Hope Say Their Super Short 155 mm Cranks Are 'The Sweet Spot'

Sep 27, 2022
by Seb Stott  


Last year we covered the surprisingly strong scientific evidence that, despite popular opinion, shorter crank arms don't compromise a rider's power output or pedalling efficiency, and in fact, may offer certain biomechanical advantages when compared to typical 170 or 175 mm cranks.

After making shorter cranks for e-bikes, Hope Technology have been experimenting with crank lengths over the last year with staff and athletes, going as short as 140 mm. They say that 155 mm is "the sweet spot" for mountain biking. As a result, a 155 mm version of their Evo crank is now available to buy.

You know it's science when there's a diagram.

bigquotes"The main benefit for gravity orientated riding is it allows you to get a more neutral body position on the bike allowing your hips to rotate to be more forward facing, increasing stability and having greater control of the bike." Hope Technology

Hope Say the shorter cranks offer the following advantages:

• "Body weight remains more centred on the bike increasing stability and making it easier to shift your body weight around."

• "Quicker to 'spin up' which can help when transitioning from descending to sudden steep uphill features." (This claim is supported by this study).

• "More ground clearance for reduced pedal strikes."

• "Lighter and stiffer due to shorter length."

Other than the length, the specs remain the same as Hope's other Evo cranks. They use 30 mm diameter axles with axle lengths to suit most bikes from XC, DH, SuperBoost and Fat bikes.

Because shorter cranks reduce the overall leverage between the pedal and the tyre, requiring a faster cadence, Hope recommend dropping your chainring size by 2 teeth for every 10mm reduction in crank length. So, if you'd normally run a 34-tooth chainring with a 175 mm crank, you'd want a 30 -tooth ring with a 155 mm crank. Hope make chainrings as small as 28-tooth. Note this will also increase ground clearance when the cranks are level.

The Evo 155 is in stock at dealers now.

Pricing (RRP)
Inc. Axle and Spider: RRP £290 / €360 / $365 (ex tax)
No Spider: RRP £255 / €320 / $320 (ex tax)

For more information, go to hopetech.com.






361 Comments

  • 881 7
 “Lighter and stiffer due to shorter length”
This has been my advertising shtick for years!
  • 9 60
flag suspended-flesh (Sep 27, 2022 at 10:03) (Below Threshold)
 ..
  • 27 5
 It's also what I've told the missus so often. Even tried to offer to levitate her to prove it, but she isn't buying it
  • 2 34
flag Eatsdirt (Sep 27, 2022 at 10:06) (Below Threshold)
 @suspended-flesh: Woooosh!
  • 3 1
 Oh boy...
  • 17 2
 @Eatsdirt: Nah - I moved my comment down a few threads so as not to detract from the humor.
  • 4 2
 Joke: Why do the nurses give old men Cialis while in the hospital?
  • 23 2
 This gives me Hope...
  • 1 15
flag SendItEveryday (Sep 27, 2022 at 11:52) (Below Threshold)
 comment gold @mikelevy
  • 4 0
 LOL, I betcha it never hit that sweet spot and it was never that sweet! Big Grin
  • 2 0
 @honda50r: tell me!
  • 7 0
 Pair these cranks with a 28 tooth front chainring and you may spin fast enough to start flying.
  • 1 0
 This is what she never said...
  • 2 0
 @blowmyfuse: SO THEY WON'T ROLL OUT OF BED
  • 1 0
 @honda50r: that's a winner! I mean...weaner. Beer
  • 313 0
 after years on 175mm i tried the 165m...it was really an eye opener...I saw absolutely no change in my abilities
  • 3 2
 edited
  • 34 3
 Pure fuckin gold. My experience exactly. Although less pedal strikes is quite sweet to be honest.
  • 26 6
 "don't compromise a rider's power output" but drop 2 teeth from your chainring. certainly.
  • 41 6
 @baca262: I’m sure someone else has already addressed this in the comments, but dropping a chainring size is necessary to compensate for shorter cranks (and vice versa) and it has no affect on power output. You have to spin shorter cranks at a slightly higher rpm to do the same amount of work (in physics work = force/distance). Because your foot is traveling a shorter vertical distance during the power stroke (due to shorter crank length), it has to complete that task more times (higher rpm’s) to do the same work to propel you at the same speed. So rider’s running shorter cranks will run slightly easier gearing and spin slightly faster to generate the same power and go the same speed #themoreyouknow
  • 11 22
flag baca262 (Sep 27, 2022 at 13:32) (Below Threshold)
 @TEAM-ROBOT: strictly speaking in technical terms, yes. but do go and try 100mm cranks. i'll see how far you get.

basically, it should be height dependent, like wheel size should.
  • 23 2
 @baca262: or, instead of following your thought experiment, I can look at studies that all show that crank length doesn't really matter for pedaling efficiency or maximum power.
  • 3 0
 @putin-you-ugly-mother-f*cker: That's why I got them beginning of this season, not regretting it at all!
  • 20 9
 @TEAM-ROBOT: spinning cranks at a higher rpm vs pushing a bigger chainring with longer cranks may allow you to equal The same Power output according to the studies, but your body has to work in a different way to do so. Higher cadence = higher heart rate

Kinda like the more reps at lighter weight vs fewer reps at heavier weight debate

Not necessarily better or worse, but definitely different.
  • 8 3
 @SonofBovril: Not too mention ones knees? Always my knees that scream at me first when i'm spinning out. Though maybe the effective rpm change isn't actually that much. But maybe bicylce cranks have been these sorts of lengths that we more commonly use forever, for a reason?

disclaimer: i just smoked a bowl.
  • 4 0
 @SonofBovril: but foot speed doesn't change. What you described is like going from seated 90rpm pedaling to standing 60rpm pedaling up the same hill.

What shortening cranks does is different. It's like going from 10 full reps with 10 pounds, to doing 20 half reps with 10 pounds.

Per the article linked from this one: "In other words, riding with shorter cranks requires a faster cadence (and longer cranks a slower cadence); but with the right cadence, the crank length doesn't significantly affect the metabolic cost of pedalling at a given power output."
  • 9 0
 @SonofBovril: Gotta say, in my experience higher cadence = lower heart rate at the same power output. When I've got my trainer going set at a single wattage I find it much easier to maintain a higher cadence (~100 rpm) than a lower one (say ~80 rpm).
  • 1 0
 @TEAM-ROBOT: Agreed. I moved from 170 to 165 cranks without any other changes and the extra work my legs do on the climbs is significant. Need that easier gear.
  • 3 0
 @ljblk: I went from 175 to 165. Lost two teeth on ring and seem to have the same basic gearing as before. Most importantly the granny gear. Your calculations may vary.
  • 7 1
 @woodc85: Higher cadence is proven to be lower heart rate if equal power. It's why it is so important to learn how to spin a high cadence. Although 100 is very high, and anything around 85 and up is generally considered a high cadence.

Spinning is winning.
  • 7 1
 @alexisfire: 85rpm is high cadence? Maybe for an e-biker?
  • 8 10
 @TEAM-ROBOT: so next year every bike in roadracing will now have short cranks, every bmx race bike every velodrome bike. In the whole history of cycling hope have only just discovered that short cranks are the best. No thay have not. its bolloks because hope want to sell some newcranks. short cranks are popular now purely because of low BB heights of todays bikes. And on an ebike it doesn't really matter because you have a motor helping you out.
  • 3 0
 @TEAM-ROBOT: Emphasis on the word 'slight'. Changing the ring probably depends on how much you use the giant cogs in the back.
The benefits are numerous, IMHO, from the fewer pedal strikes, the having your feet closer (I would think anyone with a moto background would appreciate, less knee bend angle, etc.
Doesn't take long to adapt.
My 165 XTs are still fairly new - and weren't easy to find - so I will hold off on going shorter, but I sure as hell won't be going longer ever again.
  • 1 5
flag blowmyfuse (Sep 28, 2022 at 8:41) (Below Threshold)
 So all of this thought implies people have the same slow & fast twitch muscle fiber activity to call upon with any given set of crank/chainring combo.

But people who move slower, but can generate more power in that timeframe, how does this help them?

I'll use track sprinters. All studies show that everyone has the exact same leg speed when running. But...the difference between you and Usain Bolt is how much force he is generating at push off of each stride that propels him forward.

Knowing that, how does it apply to guy with a bum knee riding 175mm cranks and a 30 tooth ring ?

Making him switch to 155mm cranks and a 28 tooth ring...I just don't see it being of any benefit. You're pulling 20mm of leverage off a guy who can't generate much force to begin with and removing the leverage he depends on to get that 30 tooth up a grade.

Drop him to a 28 tooth ring with that bum knee, you've taken away a relatively large 20mm mechanical advantage and given him an only slightly smaller chainring to turn...but he has to turn it faster and at more repetitions to do the same amount of work.

That sounds like agony to my bad knee.
  • 6 0
 @blowmyfuse: power is force*distance over time, right? So let's say we make a crank 10% shorter, and make the chainring 10% smaller. On the old setup we were doing 5 pedal strokes, so now to turn the rear wheel the same amount we must do 5.5 pedal strokes. The distance has stayed the same, and the force has stayed the same. I think we're on the same page so far. The only thing that changed is that we have to do more "spins" for the same distance at the pedal.

So when you say "he has to turn it faster and at more repetitions", you're right, but you're forgetting (or glossing over) that now instead of moving your knee through a certain range of motion, you're moving it through a smaller range of motion. And according to the science, the human body is similarly efficient in both scenarios.

So the question is would you rather do 10 full squats on your bad knee, or 20 half squats? It probably depends on the person, and what's going on with the knee.

For me, I'll take the clear advantages of my 145mm cranks (way way way fewer pedal strikes), knowing that the science indicates that I'm not losing any significant power.
  • 3 0
 @sdurant12: The question is how are you getting ANY pedal strikes with 145mm cranks???
  • 6 0
 @blowmyfuse: I'd say the opposite. Generating force through a knee that is at a significantly greater angle seems like more of a cause for knee pain, even if it is a greater force.



*** not a medical professional and may be talking completely out of my ass.
  • 2 0
 @sdurant12: fool can't even tell a thought experiment from an actual experiment yet he has a big mouth. can't fix stupid
  • 1 0
 @theberminator: I hear you and when I went to 165 from 172 on my road bike my ftp went up and yes I had to spin a bit more but also a bit more cornering clearance but the real gains came on my TT bike with 160 - was thinking at the time 155 may have been a little too far - can get a lower tuck (kind a opposite of the pedal strike problem on mtb) and pull a taller gear (60t) so more power more speed and at my age no more hip pain and even the odd podium……..
  • 2 0
 @ripcraft: The difference is that your knees are bending more when you have longer cranks, so when you're spinning out you're experiencing more extreme knee flexing than you would with shorter cranks. Maybe your knees are screaming at you because they can barely take it at the normal cadence.

Comparing the same power output and pedaling force, you're spinning a longer crank slower and bending your knees more than with a shorter crank.

To make an educated guess as to why crank lengths have been consistent over time, take the related example of wheel size: 26 was the standard for mountain bikes for a long time before people started experimenting with bigger sizes. What I would call 'market inertia' - the tooling already exists, everyone is making money and not looking at a high-cost way to differentiate their product - made it easy for companies to keep the same wheel sizes. In other words, no one had to think about it, so they didn't. Once somebody starts looking into it and advocating for different options (Canfield in the case of short cranks), then others start following.
  • 1 1
 @sdurant12: For my knees, the pain comes from not having much meniscus left. So the power phase of the stroke with leg extended is the painful part. More fully extended repetitions equals more pain.

Not arguing against the quasi-science, just applying it to my bones. Beer
  • 1 0
 @3dp: I left out the potential aero gains cos...this is Pink Bike. I am sure I get enough neg props for my user name alone..
  • 138 3
 Of course they are the sweet spot…… how else do you sell a product all over again.
  • 31 0
 I love 165mm cranks- I'd try these
  • 82 55
 In other news Donald said he would make america great again, guess what that was bullshit too.
  • 11 15
flag norona (Sep 27, 2022 at 9:59) (Below Threshold)
 @hamncheez: I use 160mm on my ebike and yes made a big difference, I did it because of pedal strikes climbing steep tech, but it improved a lot more
  • 35 0
 How do we increase the margin without increasing the price? Dave's got an idea...
  • 8 0
 Happy with 165mm cranks. I can see myself be happy with shorter too but I don't agree with all the claims. Yes with a staggered stance you won't be able to rotate your hips in both directions but that's why you need to be able to switch forward foot when go from a left to right hand corner. You may tuck low when deep in the corner but you'll straighten when exiting a corner and that's where you've got room to switch feet. Having a bit of distance between front and rear pedal gives you something to lock yourself in and keep hold of the bike. That said, if they say 155mm is the sweet spot and not the 165mm I have now, I have no reason to not believe them. Like most components on my bike, I only replace them as the break or wear out so I don't expect to give this a shot anytime soon. (Currently running Shimano Zee 165mm cranks and they're doing fine so far).)
  • 3 0
 @Fix-the-Spade: Best conment
  • 6 6
 I don’t know what the sweet spot is, but if you’re going to go shorter, I wouldn’t think you would feel much of a difference until you’re about to 20-25mm shorter than what you’re used to. I hear guys talking about fewer rock strikes on 170 or 165mm cranks vs. 175. I mean, if you say so. I suppose every little bit helps, but I can’t imagine less than a quarter or half an inch is going to make that much of a difference on a bike with 140-160mm of rear travel when it comes to hitting rocks. When the cranks get to be an inch shorter, well maybe you’re getting somewhere.
  • 12 3
 @TheR: I'm not pro, not even close. I'm average, but I can 100% feel the difference between 175, 170, and 165. I'm not talking pedal strikes either- its easy to feel the difference just by pedaling around the parking lot.

I'm not short, I'm 5'9", but the first time I hopped on a bike with 175mm crank arms I felt like something was off. I didn't like it at all. I kept them because I was poor at the time and everyone said you pedaled more efficiently with them, but that most likely isn't true.
  • 6 0
 @Fix-the-Spade: It wasn't Dave's Idea, he nicked it from chocolate bar manufacturers.
  • 1 3
 @hamncheez: I don’t think I’ve had a bike with cranks shorter than 175 since I was 10 or so. This includes BMX bikes from when I was a kid. I’m not saying it’s right, or that there’s nothing better, just find it strange that there was a first time you hopped on 175… seems like that also would have been the first time you hopped on a bike, as it’s been the standard for so long.

Anyway, I really can’t tell any difference between 170 and 175 in terms of just pedaling the cranks. I rode 170s on my trainer and had to check what size they were. Definitely no loss of power.

I’m not opposed to giving shorter cranks a try, and I’m kind of curious. But I think they would have to be at least 160-165 before I could register any difference. Other than fewer rock strikes, what do you feel the advantages are?
  • 2 0
 @TheR: Thinking of it, maybe it is quicker to flip the leading foot (when weaving through alternating corners). It's been a while since I switched to 165. I think I got my Zee cranks a few years ago but before that I've spent a good few years on Truvativ Ruktion cranks which were 165mm too. The cranks I had before that were 2004 Shimano Deore LX cranks (so Hollowtech Octalink, just before they moved to Hollowtech II and introduced the nearly similar Hone set). It's been a while so it really is hard to recall what it was like exactly. But I do think it was quicker through those corners as corners have always been the think I cared most about (and I cared very little about pedaling efficiency or pedal strikes indeed).
  • 3 0
 Happy with my 165 but when changed from 175 because of pedal strikes noticed an unplanned benefit: had my OneUp 210 shimmed to 190 because of a combination of my saddle height and minum insertion and could then remove partially the shims to make it 200. Wouldn't mind to change to 155 and remove all shims.
  • 2 0
 *maximum insertion
  • 2 0
 @miguelcurto: Dick Pound approves
  • 1 0
 I was gonna say... looking forward to every other rider in spring telling me they just put 155mm cranks on their bike because they're really "the sweet spot".
  • 122 0
 Canfield saying we knew this 10 years ago.
  • 18 0
 2000 and late
  • 35 0
 That and DH bikes with idlers.
  • 5 0
 Yep got 155's on my new dh build. (and 160s on my trail bike cause of those dudes).
  • 7 7
 You know it! check out my video on 155 Canfield cranks: www.youtube.com/watch?v=mKIINVxNQNM
  • 7 0
 Mountain unicycling is so far ahead of all of this.
  • 6 0
 So true, I've been running the 155's on my DH Jedi for at least 7 years. I run 160's on my Balance and Nimble 9 too. They have always been well ahead of the progression curve.
  • 2 0
 @Funkylicious: I have run Canfield 160s for a year now and am very happy with them. Have had 180s on BMX, switched to 170 and it felt much better, 175 and 170 on MTB now 160. I would like to try 165 sometime but they weren't in stock last year.
  • 100 4
 "Last year we covered the surprisingly strong scientific evidence that, despite popular opinion, shorter crank arms do compromise a rider's power output or pedalling efficiency, and in fact may offer certain biomechanical advantages when compared to typical 170 or 175 mm cranks."

Glaring typo - should be "DON'T compromise." Also, pedal (one L) ing.

Not to nit-pick, but the entire point is negated without NOT in there. Is anyone reading articles before they're published?
  • 23 0
 My brain hit an error bar at that sentence
  • 34 1
 How is anybody down-voting this comment?? The difference between "DO compromise" and DO NOT changes the meaning of the article.
  • 7 1
 @Marquis: possibly they are just reading the now-edited version
  • 15 2
 @overconfident: then they can just ignore this comment, because it was obviously fixed because of it, but PB never puts a notice when they fix mistakes.
  • 1 1
 @Marquis: agree though maybe they're just inferring the meaning from the context.
  • 6 0
 @Marquis: If I was going to downvote myself, it would be for my snarky tone and "correction" of the British spelling of "pedalling," which is actually correct.
  • 6 0
 @Lokirides: The shooter pumped rounds in to the opening paragraph before turning the gun on himself.
  • 9 1
 @Marquis: People have not had any reading comprehension skills for years, and the Internet has steadily made it worse.
  • 2 0
 @justinfoil: they should, yes
  • 2 0
 @TheR: what's with the username I love it makes me say THUUURRR like I'm all beefy
  • 3 0
 Does it even matter? We know they would come up with anything to sell the wheel again.
  • 2 2
 Short cranks do rule. I also think in many cases they are used to compensate for everyone spec'ing coils on their long, low, slack, bikes. They will sell us "More ground clearance for reduced pedal strikes." because they took the clearance away making bikes fast, low, and stable (as they should be).
  • 1 1
 Also... Two master links in the same chain? Cmon...
  • 1 0
 @SJA59: Have to do it with some idler setups.

You could have them all quick/master links if you wanted. Berm Peak did it, worked great, but $$$.
  • 3 0
 @jimmyconnors: It’s just the return of the brother, keepin' you up to par.
  • 1 0
 @SJA59: When the BB center and the swing arm pivot center are far apart combined with an idler and a bit of suspension travel determining chain length can be vexing.
  • 1 0
 @SJA59: I had to do it on my commuter ebike to make a longer chain. 52t front to 48t rear requires all the links... If it ever breaks from 1000 James Watts of peak power I'll come back and update this.
  • 67 1
 Bare in mind you'll have to raise your seat height to allow for the shorter length and this may affect how your stack height (when seated) feels.
  • 5 63
flag 5afety3rd (Sep 27, 2022 at 8:39) (Below Threshold)
 not necessarily true
  • 6 4
 You can also lower you BB height ?
But you also have to use lower gears, & spin gears faster to gain same power output!
  • 11 2
 Umm, kinda has to be true if you want to keep the same knee angle unless you were compromising previously (for leg length differences or something). If you don't raise the seat you will have less extension. When you raise the seat it changes your seated fore/aft weight distribution. I ended up moving to a 50mm rise bar (from 25mm rise)after going 165->155 cranks.
  • 3 1
 @BigHerm: Does suck that most bikes are design around longer cranks?
  • 2 8
flag BigHerm (Sep 27, 2022 at 9:11) (Below Threshold)
 @aljoburr: I don't entirely understand the premise. Cranks are just a requirement of the machine and the length doesn't have much to do with bike design (that I'm aware of). Now chainring size is related to anti-squat and if you go too small it affects that, but I'm back and forth between 30t and 32t (trail/lifts) which is the proper/specified size for my bike.
  • 12 1
 @5afety3rd: I guess you don't HAVE to raise your seat, but the distance from your seat to the bottom of your pedal stroke just gets shorter. Which means you won't be extending your leg as much. Most people don't like this, but you can leave your seat right where it is.
  • 3 2
 @BigHerm: crank length changes the height of the center of mass of the rider, which is an input to the anti-squat calculation. Anti-squat specs should, but generally don’t, list the height of the center of mass they used in the calculation. Regardless, changing crank length definitely changes how the suspension works when seated.
  • 26 0
 Hmm, I went with a longer dropper on my new bike and it is just about 10-15 mm too tall with the dropper collar slammed to the seat tube collar. I could get shorter cranks and kill two birds with a single expensive stone...
  • 3 0
 Came here to say this. My saddle to handlebar drop is already bad enough that I'd rather keep the 170mm cranks and have a few pedal strikes
  • 8 0
 Well thanks everyone for making it way too complicated. I'm out. Brain hurting.
  • 24 1
 @melanthius: the change in CoM of a rider due to +/- 20mm of crank length, is something under 1mm with all things(static riding position being unchanged). literally nothing.

take 2 6ft tall sticks and make them touch at the top and put their bottoms on a flat surface and seperate their base by 350mm(175mm x 2). now measure the height. the answer is that it is only 1/3rd of an inch shorter than 6'. now do the same for 165 cranks and you get a delta between the two of .76mm.

so it does change the CoM, but only be the length of your penis.

(sorry, that joke was the entire reason I did the math. don't @ me. LMAO)
  • 5 0
 @conoat: your math is valid for standing CoM, which is basically irrelevant for anti-squat measurements. His is why I specified “while seated”.
  • 1 0
 @melanthius: Didn't know that. I'm not too concerned since I have short legs and my saddle height is about where a longer legged rider with longer cranks would be.
  • 6 0
 @fly4130: I think it goes "get two birds stoned at once"
  • 2 0
 Bear*
  • 1 0
 The great thing about that it can let you run a longer dropper.
  • 1 0
 Yep and with xl seat tube lengths the way they are, I’m gonna need to buy that 240mm dropper that doesn’t exist.
  • 1 0
 @gticket: the Oneup 240 dropper doesn't exist? I could have sworn I read a press release about that not too long ago.
  • 2 0
 @Spencermon: Oneup does make a 240mm dropper
  • 1 0
 @souknaysh: it appears @gticket did not know that.
  • 1 0
 nah dude low posting is all the rage now. drop saddle, nose up the saddle, get a huge ass.

Idk I built a track bike with 165s, I'm low posting af on that thing, and 50+ miles on that thing is less painful on my knees than my road bike where I can coast. All confusing, but my road bike has 175s - not saying short cranks are better for your knees, but I think the whole leg extension thing has more to it than ppl think.
  • 61 0
 CB: short cranks sweet spot
MTB community: BLAH
HOPE 10 years later: short cranks sweet spot with colorful chart
MTB Community: Innovation
  • 5 0
 Had shorter cranks on my riot, will never go back. Lower bottom bracket and fewer pedal strikes!
  • 3 0
 Charts and illustrations are more persuasive than mere words, no matter how scientifically serious the explanation.

That and more bikes have been coming with shorter cranks than in years past. People are more accepting now, because they’ve been on shorter cranks.
  • 3 0
 Hope. All the bike nerds will buy in!
  • 1 0
 Been on 165mm cranks for over 20 years, for everything. I'm 5"11. I've never really thought about it, I just wanted my feet to be closer together for jumps.
  • 44 0
 BRB about to cut my 170mm eewings down to 155mm
  • 45 8
 175mm for life mo fos
  • 34 0
 @jimoxbox : how many 26 inch tires do you have hoarded away?
  • 15 0
 @justinfoil: maaaany
  • 4 9
flag Aburjakowsky (Sep 27, 2022 at 14:52) (Below Threshold)
 All day, I know the article/product is geared for "gravity fed bikes" but for the average enduro that still needs to climb I want leverage.... not tiny 155 cranks where I lose top end and getting out spun by my mates
  • 5 0
 @Aburjakowsky: for the same gear ratio you have more top end on shorter cranks since you spin smaller circles. Track racers have been on short cranks for like 100 years.
  • 6 3
 @sspiff: You're right, and for road biking I like a shorter crank but for technical climbing on an MTB I prefer having the longer crank, slower RPM, and better fine motor control as I'm picking my way through weird stuff. 175's on my long travel enduro bike and not going back. Worse on long smooth climbs but awesome on technical uphill stuff.
  • 3 2
 @Aburjakowsky: this is for the beer drinking shuttle riders and park rats who nac nac and crank flip. Not for your pedal ride.
  • 2 0
 @TEAM-ROBOT: Your technical uphill must be different than some/most. Around here there is a lot of either dodging things with the pedals (ratcheting) or hitting things with the pedals. "better fine motor control" (explain more?) becomes useless when you're ratcheting every stroke or scraping rocks every other stroke. I actually feel shorter cranks give your more fine control, because your feet trace a smaller circle so they go "over the top" quicker, so your leg spends less time in a mostly bent position where power and adjustments are hard to make, and gets back to the power zone faster where you can easily make a fine adjustments and even ratchet quickly.
  • 2 0
 @leviatanouroboro: Did you miss the part where power isn't really affected?
  • 1 0
 I actually think 175mm cranks and 26" wheels are the easiest for chunky climbing.
I can feel my way climbing up a rock garden better with this combo.
Maybe it doesn't match what the adverts, but its my experience.
  • 2 0
 @acali: No matter what they say about 26" I love them the most for riding nature. 29 makes some sense but 27'5 get the outfook, just so they could sell again. 29/26 is a way better mullet too. No tests and science on that one...
  • 34 1
 We all know where this is going... let's just jump ahead and attach our pedals directly to the axle for the ultimate sweet spot, crank arms are overrated
  • 5 0
 the evolution of the fixie
  • 51 0
 @overconfident: evolution of the ebike
  • 7 0
 I've made the suggestion countless times to DH park riders that they need to mount 155mm cranks parallel so that both are hanging down and ride them like moto pegs, but nobody is listening to me.
  • 4 0
 @blowmyfuse: after being ejecto-blasted out of my bike on a couple of occasions due to pedal strikes, that idea would make be ride in straight lines only
  • 2 0
 Shhhh, you’re spoiling the Grim Donut 3.0.
  • 3 1
 Future of e-bikes...
  • 17 0
 I've been on 165s since 2015 - no ragrets. There is a subtle sense of being more 'spin-y' when I pedal to the trail head, but on any kind of dirt it completely disappears and the ground clearance and overall feel is fantastic. I worried I was going to short back when I tried them, but there was zero adaptation time for me and I haven't looked back. I look at 155s and think...maybe too short, but I wonder if I tried them I'd be even happier. I also think Canfield deserves major props for pushing shorter cranks for technical riding. Those guys have been beating this drum forever, and I feel like 165s are now almost standard, or at least a common option.
  • 50 1
 Not one? Not even a single letter?
  • 15 0
 @DBone95: I don't think he has any regerts at all...
  • 5 1
 @DBone95: ...now that was funny!
  • 7 0
 NO REGERTS
  • 9 0
 for those who don't get it i.imgflip.com/1f2zwq.jpg
  • 7 0
 @hamncheez: Oh man, don't take this from me. You know what I'm sayin?
  • 1 0
 @DBone95: My guess is he played for the KC Chefs before taking up mtb. So no, no regerts.

www.youtube.com/watch?v=WPOZbG7ibEE
  • 4 0
 Yep. I'm a tall-ish guy, 6'3" 36" inseam (190cm, 91cm). On road I ride 175 and have experimented with 177.5 and even 180. My MTB came with 175s and I was thrilled with the change to 165. Far fewer pedal strikes, and I don't notice a difference when climbing.

Unlike with road biking where I'm in the same position for hours, on the mountain bike I'm all over the place anyway. Difference cadence, different body position. Shorter cranks seem like the least of the changes going on.

Maybe my pedal strikes were due to bad form. I'm willing to accept that. Regardless, problem solved. 155 seems a cm too far for me, just because it's no longer necessary. Then again, a crankarm weighs about 200g, so shaving 1/16 off two of those is a solid 25g savings!
  • 1 0
 Chuckie Finster was my favourite.
  • 2 0
 @DBone95: well I’m awake and I speak the English language…
  • 16 1
 You're also potentially buying a new chainring with any brands' shorter cranks. Costs add up. I can see why people would reluctant to spend money on diminishing returns. It's not like you'll suddenly be competitive in EWS by switching to slightly shorter cranks. You'll suck at riding just as much as you did with longer cranks.
  • 12 0
 But have fewer pedal strikes while you suck at ratcheting.
  • 14 2
 I'm 6ft 2 and ride an XL and I'll never get cranks longer than 165 again even for a full 29er. 160 for mullet
  • 16 6
 I hate the feeling of short cranks. They feel unstable and awkward to me, im 6 foot 4. I'm very surprised to read that they increase stability because in my experience its the opposite.
  • 9 2
 I've seen the argument that the wider stance gives more stability, which also makes sense to me.
  • 5 4
 At 64 your 175s are like the 165s for the average height rider. Just like all the bike/suspension tests from 150 lb riders, your results will differ. My bet is that you could put different length cranks drive side and non drive side and 75% of peoples would not notice.

I think part of this is profit driven...hey we can make the cranks use less material, ship more in the container and charge the same price. Now how can we convince them this is a good idea? Get on it VP marketting.
  • 2 0
 On the other hand..... I'm a smidge over 6'4", and decided to build up my new hardtail with 170mm cranks, and have been loving it Smile
  • 2 0
 @pink505: most people would definitely tell with different lengths. They might not be able to pinpoint it, but they'll know. Just a tiny percentage height change in a single step in a staircase will make most people notice, and many people will trip or stutter. Now repeated it for every "step"? Definitely noticable.
  • 2 0
 Same. I actually went from 165s to 170s on purpose on a dirt jump bike because I felt better with the wider split stance.
  • 2 2
 It’s logical that taller riders need longer cranks.

Yes - short cranks spin up faster, makes sense. No way to the claim that short cranks have same power, the longer lever has more power. This is why they suggest smaller chainrings- you can’t push the same gear up a hill with 155mm cranks thst you can with 175mm.
  • 3 1
 @S4-916: @S4-916: Barring some biomechanical factors, power is indeed the same: the ultimate power limiter is your cardiovascular system, and that is (hopefully) completely independent of crank length. The effective gearing is different between 155s and 175s, hence the need for a chainring size change. Look at the ratio between crankset radius and chainring radius.
  • 4 0
 @MaplePanda: So I should switch from my 175/30T to 155/26T (my gearing for BC riding), for almost exactly the same power, and ostensibly some better movement on the dh, but a higher centre of gravity due to the 20mm higher saddle height. This is now my understanding of what they’re selling.
  • 2 0
 I read a few things from BMX companies (FITBIKECO and another maybe ECLAT) saying that having your feet closer together gives you more pop! The science says feet closer = jump higher. Not as important for MTB but I thought it was worth trying 165 on my BMX and now I run 165 on my hardtail too. Feels fine, pedaling is the same but many along got harder/adjustment time.
  • 2 0
 @S4-916: Dont forget fewer peddle strikes and less weight ( shorter cranks, smaller chainring and 4 fewer chain links) and all you need to do is peddle at a 13% higher cadence on the uphills in that monster 52 tooth cog.
  • 1 1
 @S4-916: Higher center of gravity only when seated and pedaling, won't affect CoG for DH that much). You also may find you don't need to match your saddle increase to your crank decrease. Since the top of the pedal stroke is 20mm lower, a 15mm or 10mm saddle raise might still feel great since knee flexion is lower overall. This also might really help some folks who have toslam their long dropper but still find it a tiny bit too tall.
  • 1 0
 Same. I went 160 on the ebike this year and the standing position bothered me more than anything else. Felt like my legs were too close together and less stable if nothing else. But I did get used to it and now I love them.

Also running 165mm on the regular bike, looks like those are obsolete now?
  • 1 0
 @pink505: my frame seems to have a minimum chainring size of 32t (smaller than 30t rubs on the chainstay, 30t is too close, and noisy, for comfort), but i'm still going shorter next time I get cranks, and I'll guess i'll just make 13% more power with 32t driving only a measly 50t cog.
  • 4 1
 In mountain biking it's important to sell the same story to everyone regardless of circumstances. Crank length, stem length, saddle length/width, bar backsweep/upsweep/width, mullet vs dual 29: one answer for everyone because we're too dumb to handle nuance of any kind. Manufacturers pitch a single story so they don't have to accommodate anything but their own convenience.
  • 2 0
 @src248: Wider stance isn’t always better for kinesiology. Our hips limit how much width is beneficial for movements. Squat stance is a good example.

Also, the stance isn’t exactly wider with longer cranks. It’s purely more hip and knee flexion. To be wider, your pedals would have to wider. Hope that makes sense.
  • 1 0
 @pink505: I’ve never tried a 26T / 52, but I know 26T / 50T is almost unrideable, I put it on my gf’s bike and it’s so slow on steep uphills, tough to balance.
  • 1 2
 It's a Hope pre-release so I'd take it all with a giant pinch of salt. If you added up all the 12-18% (it's always around that mark, coincidentally) increases in power that every iteration of the Tech lever has had over the years, the Tech 4 should be able to stop the Earth spinning on its axis.

See also their claims about the Pro 4 flanges being fractions of a mm wider and how that would be a huge improvement on wheel stiffness (despite then changes only affecting spoke length requirements by about 0.2mm for most), then making their own narrow hub standard for their first complete bikes.

I just find it hard to believe anything they say, no matter how many colourful charts and infographics they make. See also: Magura.

The thing with the length vs. stability for me is that if you have someone stand in front of you try to push you over, your feet being spaced further apart fore-aft will make it easier to resist than having your feet closer together. I know that's not a parallel for riding, but in almost all instances extra width improves stability (to an extent obviously, we don't all need 820mm bars).
  • 1 0
 @CleanZine: Longer cranks mean more leverage, a la easier to move around. When you get jostled on a rock the wide spacing of your feet allows for more freedom of movement whereas closer spacing provides more resistance. Great points regardless. I’ll probably still buy a pair, the difference is extremely advantageous between 175 and 155 for me.
  • 1 0
 @S4-916:
Even 34T /52 is almost unridable, tough to balance if the cadence is low.
26T /52 doesn't have to be slow, if the cadence is fast enough.
  • 1 0
 @Hexsense: Depends on the mountains you’re riding. Around here in BC, climbs are steep and long. Most people ride 30T I think. 34T you either need to be pro-level fit, or you’re walking.
26T/50T is so low a gear that you’re spinning like crazy, but going so slow that you’re wobbling around. 26T/52T needed for 155 cranks would be unrideable.
  • 1 0
 @S4-916: with shorter cranks your feet don't go around as big of a circle, so higher cadences are much easy to handle. It's like a long stroke vs a short stroke piston engine. The long stroke will develop more instantaneous torque at low revs, but the short stroke can rev much higher and makes more power overall. You might have to spin faster with shorter cranks, but it will be way easier to spin faster. You also may be able to make more power because you leg doesn't have to bend as much, keeping it closer to the sweet spot of max muscle power. Really, it's all benefits for shorter.
  • 9 1
 Without designing the frame around the shorter cranks, the biggest advantage (lowering COG when descending) is arguably lost here (unless you have a ton of pedal strikes to deal with on your existing bike).

In the era of dropper posts, shorter cranks make a ton of sense. Prior to droppers/2010 or so, the reduced saddle to crotch clearance descending was just too much to deal with.

I actually built some bikes for super short cranks for tests (published in Mountain Flyer about 6-7 years ago. They were pretty great and there wasn't a power output disadvantage, but it was too hard of a sell for most people.
  • 2 0
 This is why I'm putting short cranks and 27.5 wheels on a 29er (pivot firebird)! Just waiting on the spokes to arrive
  • 11 2
 How do shorter cranks reduce saddle to crotch clearance? When standing at 3 & 9, the triangle between your feet and crotch is narrower, and thus taller, with shorter cranks. That increases saddle to crotch. With one foot dropped, since your saddle shouldn't have gone up any more than the cranks got shorter, you should have the exact same saddle to crotch distance.

How are frames designed around cranks? Beyond having a reasonable minimum for BB height?

"but it was too hard of a sell for most people"

Ok, but why? What did they not like?
  • 6 0
 @justinfoil: if you're cranks get 30mm shorter, then for the same leg extension at the bottom of the pedal stroke, your saddle will need to be 30mm taller.

Your stance does get narrower, which does mean you get a little higher. But not much. Going from 175 mm down to 145 mm cranks, you would raise the saddle 30mm, but only end up 10mm higher up when standing (based on a 30 inch leg length). Meaning you've lost 20mm of clearance.
  • 2 0
 @sdurant12: excellent, I did that to a sentinel. The handling with the ultra low bb was amazing, and since you’re not changing bb drop, just lowering the entire mass, it still pops and manuals as designed. The only downside was chainring strikes in rocky areas, but I got used to it and learned to pick lines accordingly.
  • 2 0
 @ivemadeahugemistake: I'm excited! The spokes just arrived an hour ago. Is this on the current sentinel? If so I guess you ended up very low, as that bike starts 10mm lower than my firebird in the high flip chip.

Did you go for +20mm on a 27.5 fork, or did you stick to the 29er fork? Or something in between?

And did you go to a super small chainring? I'm considering a 28 tooth combined with an e13 9-45 tooth cassette to get some ground clearance back.

Sorry about all the questions, just excited to hear from someone who tried something similar. Hopefully your username isn't referring to this particular setup Big Grin
  • 2 1
 @sdurant12: full 27? nah, go mullet!

...unless you really need the slightly lower stand-over, or lower stack...
  • 2 0
 @justinfoil: I *want* to go mullet, but I'll end up with a slacker seat angle than I prefer if I do. Unless I shorten the fork but I don't want 150 front/165 rear.

So 180/165 full 27.5 it is.

This is for my park/shuttle/winch and plummet bike. I am planning on getting a lightweight trail bike with 29er tires to cover the rest. Crank length on that bike is TBD - probably in the 155-165 range, depending on the BB height of the bike. All of this depends on how the full 27.5 conversion goes. If it's more versatile than I'm daring to hope, it could end up being my only bike.
  • 3 0
 @justinfoil: To get your usual leg extension, you have to raise your saddle. So if it's normally 75cm from the BB with 175mm cranks, you need it at 77cm with 155mm ones.

The stance being shorter makes a tiny difference but it's not enough to worry about.

If you want to test what it feels like on a rigid post bike, you can just wait until the top of a downhill that doesn't require any pedaling and raise your saddle 20mm and see how it feels. You probably won't like it much, and that's why nobody really tried to use shorter cranks on mountain bikes in the 80s or 90s or 2000s.

With a dropper, of course, it's no problem. But those weren't common prior to 2010 or so, which is why we're all still on the same 175mm cranks still - the bike industry moves slow.

-W
  • 2 0
 @waltworks: My point is that you might not need "normal" leg extension" because the entire pedal stroke becomes shorter. In the example of 175 to 155, the bottom of the stroke is 20mm higher but the top of the stroke is also 20mm lower, so raising the saddle by 20mm is not always necessary since you won't get the same maximum flexion.

Considering how many times I've heard bike fitters mention how common it is to see too high of a saddle and the associated hip rocking, robbing people of power, and potentially causing joint damage... well, perhaps not needing to send the saddle sky-high to make it feel good at max flex is a good thing overall.

"If you want to test what it feels like on a rigid post bike"

I don't want to. I have droppers, I will always have droppers, and shorter cranks often allow the use of a longer dropper: since the top saddle height is higher you're that much further away from having to fully slam the post.

"wait until the top of a downhill that doesn't require any pedaling and raise your saddle 20mm and see how it feels."

I have. Yes it's weird, but less weird with 180+mm of drop, even it's kinda like 160-170mm since that bottom height gets raised. But it's not world ending, can be gotten used to, and again, matching the saddle raise to the crank shortening numbers exactly is not always necessary.

I know I mentioned droppers a lot, but that's because if you're high-medium-posting with a rigid post, maybe short cranks just aren't the right fit for that ride style any way. Many of the benefits of super short cranks, like better/easier bike-body separation, easier to get real low without burning up your rear-ward calf and glutes, etc, just don't matter as much if there is a tall saddle in the way.
  • 1 0
 @sdurant12: current one. Bb ended up just under 330mm static, so yes it was very low. I used a 180mm 27.5 fork, but had a -1.5 angleset which canceled about 10mm of the extra axle to crown. Also had a cascade link to bring the rear travel closer to front. And a 30t chainring for clearance, which was honesty the only downside to this setup. I Spent a lot of time in the highest gears of the cassette, but otherwise it was a cool park bike, it loved corners and it pedalled as well as a stock sentinel, minus the slower rolling wheels.

I ended up getting a new patrol, because that’s basically what I wanted from my sentinel, and the 29er up front is great for taking the harshness out of brake bumps.
But if you love a full 27.5 setup I think Frankensteining a 29er is a really viable option. Enjoy!
  • 1 0
 @ivemadeahugemistake: crap. Braking bumps being harsh is one of the things I'm worried about with a full 27.5 setup

I built up the rear wheel yesterday. I will see how I like the mullet and then maybe make the move to full 27.5

As for the small chainring, I may end up running an e13 helix gravel cassette with a 9-45t range to help. Something to consider.
  • 1 1
 @justinfoil: Well, I mean, I've actually *done* the experiment (with a power meter and oxygen consumption tracking, in a lab!) with bikes purpose built for short cranks, but if what you want to argue is that getting full extension doesn't matter, that's fine, I guess.

You really need to try doing a sustained ride with with short cranks with your normal (for 170/175 cranks) saddle height, then try the same ride with the saddle raised to get full extension. I think you'll find out quickly which you prefer.

-W
  • 1 0
 @waltworks: I'm curious - it sounds like you've done a lot of experimenting.

What did you find to be a good bottom bracket height with shorter cranks? Did you find yourself able to lower the BB as much as you shortened the cranks? Or did you find that if cranks get 20mm shorter you can only go, say, 10mm lower? Pedal strikes don't always occur at the very bottom of the pedal stroke, so I'm wondering what you found to be a good compromise
  • 3 0
 @sdurant12: Believe it or not, if you go down to 155mm or shorter cranks with correspondingly lower BB, and you're not running a tiny chainring, what we started to find was that chainring hits (while still rare) were a bigger issue than pedal/crank strikes.

In theory, you could put 110mm unicycle cranks or something on a mountain bike and run a super low BB, and while your pedal strikes wouldn't be a big problem, you'd wreck your chainring/chain unless you ride really smooth trails.

Overall, though, you can basically drop the BB about the same amount as you shorten the cranks.
  • 12 0
 Is no one bothered by the two quick links in this pic??!?
  • 3 0
 Must need more than one full chain for that high pivot.

I have 2 quick links in my chain because I tried a smaller (oval, too) chainring and shortened the chain for it but didn't like it, and a second quick link is the easiest way to put the missing one back.
  • 3 0
 @justinfoil: I have two quick links in my chain because I suck at setting up the chain length the first time every time.
  • 1 1
 @warmerdamj: And you suck at making up stories to "explain" 2 quick-links
  • 14 2
 Pick a crank length and be a dick about it
  • 8 0
 Can't necessarily choose the length of your crank
  • 9 0
 Pick a dick and crank it
  • 13 4
 Just more bullshit...you just open up a can of worms let's buy shorter cranks marketing..oh shit now I need a longer dropper..oh I need a higher rise bar..oh I need a smaller chainring..ect ect.. meanwhile.your bike was fine
  • 2 0
 This is definitely true, but then in 5/6 years time when you buy a new bike, it's got lots of small improvements that add up to a better/faster bike overall.
  • 9 0
 I hope this proves that tis better to pick a crank length and be a dick about it, than pick a dick length and be a crank about it.
  • 2 0
 You know what they say about a rider with short cranks?
  • 10 3
 I run Canfield 155's on my Lithium, I will confirm that this is the sweet spot. It makes me giggle to read and hear all the naysayers, some folks can't see the forest through the trees.
  • 7 0
 I think that there is still a lot of different body types and people that have a preference. Even if it's better, it can still take some getting used to, and for some people that have been riding a long time, they might not ever get used to the difference.

edited to add: unfortunately in this article, it does not state if this applies to every inseam and leg length or just the average. Hard to say that everyone should ride one crank length. Kinda how we don't recommend everyone ride the same width handlebars.
  • 9 1
 Man, I bought into the hype and tried 155's and 165's last year and found myself gasping for air on uphills. I'm just over 6' and subjectively I felt like I couldn't get enough leverage. Went back to 170's and it was a huge relief. If I was shorter or just rode park I could see more of a benefit. To each their own.
  • 2 1
 @dirtdiggler: did you also get a smaller chainring?
  • 1 2
 @sdurant12: nope, that’s a misnomer about short cranks, there’s no need to change gearing.

Think of shorter cranks like you might think of a shorter whitewater paddle: back in the day, whitewater boaters used really long paddles, > 195cm, but over time the paddlers found that using a shorter length improved efficiency and increased cadence.

Too ess as ch their own, but I learned about short cranks years ago while riding muni, found 150mm cranks to be the sweet spot, so no surprise that prefer the same on a bike.

For perspective, I’m 6’ tall, riding 150-160mm cranks on all my bikes.
  • 2 1
 @dirtdiggler: nah, it wasn’t the crank length, it was climbing a hill with inadequate fitness Wink
  • 2 0
 @sdurant12: Not at first, but eventually went down 2T. It was a little better but I still couldn't get adjusted after a few months of riding. I'm not against it, it just didn't work for me out on the trail.
  • 3 0
 @sanchofula: If I stuck with the short cranks I would have definitely increased my fitness! My heart rate went up at least 15-20BPM over my 170mm cranks as I was spinning the shorter cranks much faster to make it up same hills. When I went back to 170's I felt like I was riding an e-bike...lol!
  • 11 3
 As a 6 foot rider who's used 155mm crank arms I can say for a fact are horrible to ride compared to 165mm or 170mm crank arms.
  • 8 0
 Great for an Ebike where pedalling is just for show anyways. I cant imagine pedalling up steeps on a non-Ebike with 155mm cranks. No way
  • 6 0
 Love my 155mm Canfields. Don't love the Canfield GXP BB that smoked a NDS bearing in 7 months. Fingers crossed the Wheels MFG replacement lasts a bit longer. More options more betterer. Good on ya Hope.
  • 4 0
 I put the 155mm @canfieldbikes cranks on this spring and am in love.

However, I bought their GXP BB to go with it. Just like your experience - HOT GARBAGE. That BB was trashed in 3 months. Cleaned it and repacked perfect and the cranks still had play (torqued perfect) and sounded like gravel. Disappointing. Never reached out to see if they could help me, but maybe I should have.
  • 1 0
 @Nwilkes: Yeah, after researching GXP BBs I just concluded that they (all) kinda suck and are ticking time bombs. I went with the Wheels one so I can just replace the NDS bearing when it inevitably blows up. I didn't bother contacting Canfield, wear items just seem like the cost of the sport. Also, I think mine was included with the cost of the cranks?
  • 5 0
 @BigHerm: I actually use a Hope BB with their GXP adaptor...lasted about the time that 2x SRAM ones would have so far, with zero issues and zero maintenance
  • 1 0
 Have them too for good few years, changed the bb myself start this year as bearings fecked. just changed the bearing for a stainless-steel version off ebay and pressed in into the canfield bb cup. The gxp uses the same bearing as hollowtech but with an insert if can't find the special size gxp
  • 1 0
 @BigHerm: It's an additional $35 to throw the Canfield BB in your cart at checkout.

I just bit the bullet and found a decent deal on a Chris King GXP BB and have been happy days ever since. Noticeable reduction in drag.
  • 10 1
 According to SRAM 153.99mm is the optimum.
  • 5 0
 Currently running 155mm NX cranks, and I'm unconvinced...I think 165 are better for me. I prefer 165 over 170 anyhow. (5'10"/176cm tall) The interactions between seat height and bar height and crank length are sort of fun though
  • 5 0
 I have big legs - short cranks make me feel like I can't fully extend and use my leg strength. Feels like I get more lactic acid build up. Also I feel like I'm pedalling a hamster wheel. I must be alone in this? Guess I need to do more testing..
  • 4 0
 You are not alone....
  • 4 0
 I’ll Just continue to follow what the pro xc guys ride, if there’s an advantage to be found they’ll find it. Nino runs 175 mm with 38 tooth chainring, so why doesn’t he run a 155 if it’s an advantage? We’ll because uphill and downhill biking are quite different I’d assume.
  • 7 1
 Anything shorter than 172.5 and my knees hurt. Personally short cranks are a no-go on any bike meant to be pedaled uphill.
  • 1 0
 I had the same issue, except with 165. I can run 170mm, but still prefer the 175's. I would try 155's, maybe the inbetween hurts. But I am not spending that kinda money just to find out they hurt my knees.
  • 1 1
 It's been my understanding that shorter cranks are easier on the knees?
  • 6 0
 Heck yeah! Though personally gonna wait for Shimano to release theirs autumn 2042.
  • 6 0
 The human body is a large enough variable that a "sweet spot" for anything related to fit and biomechanics cannot exist.
  • 6 0
 Oh that explains why the bin full for 155mm cranksets I have for sale suddenlly became popular...
  • 3 0
 Ah yes, with wheel sizes already firmly revamped it's now time to correct the next thing we've been doing wrong this whole time. After 10 years of getting everybody on 155mm cranks it'll be time for the 5 bolt disc rotor and hubs. What idiots we are, using 6 bolts or a lock ring. 5 is clearly the sweet spot.
  • 2 0
 @barp: those crazy sons of bitches.
  • 3 0
 At the moment we only have three cranks lengths commonly available, 165, 170 and 175mm. That’s only three sizes with less than 3% change between each size. Imagine if a small bike was only 3% smaller in reach than a medium and a large was only 3% bigger - and you only got three sizes to choose from. E.g. Small = 447mm, Medium = 460mm, Large = 473mm

Having such a small range of crank lengths available is more convenient for bike companies but worse for riders.
  • 5 0
 Is there a typo in the first sentence? I had to read it like 3 times and I'm still confused
  • 1 0
 They fixed it now...
  • 6 0
 The 'sweet spot' for who? Humans are fairly varied in dimension.
  • 1 0
 I think you can assume an average human, an average rider, or perhaps an average male phenotype, depending on their sample pool. Take your pick.
  • 2 0
 Been running short (Canfield 150 and 5dev 145 mm) cranks and like them, even though I'm 6'4. Free clearance with no significant downside imo. I'm a fan for pedal days (up to 60 miles/8k vert) and park days as well. Might go back up to 155ish for the pedal bike, because chainring clearance becomes the main issue anyways, so there are diminished returns going to 145
  • 4 1
 Noted: "...main benefit for gravity orientated riding..." Depending on where and what you ride, climbing performance can suffer significantly. Fire road/green trail grinds, no problem; technical and steep, less advantage.
  • 1 0
 Yeah, I wouldn't want short cranks on my trail hardtail. My 165s on my enduro bike aren't so good for scenarios where you want to get a signal pedal stroke in. Short cranks don't feel to different for consistent power, but they feel way better for high rpm sprints.
  • 2 0
 When I went from 175mm (which were way too long) to 165mm I did not feel the need to drop a chainring size. My technical climbing improved, and I can now effectively get up and pedal out of the saddle which I could not before.
I am now trying to find 165mm cranks for my road bike. The 172.5s feel absurdly long.
  • 6 4
 Elephant in the room. There is less torque on the rear wheel (in same gear) with shorter cranks. Short cranks will tire your legs quicker unless you are spinning like a roadie. Spinning like a roadie while going up technical trails is bogus, you all know that...
  • 3 0
 I just watched a video from Gene Hamilton (Your MTB Cranks are Too Long) that was saying the shorter cranks put you in a better squat position, which kinda makes sense. So if it's putting you in a better power position it might not be all bad. I also would take the pedal clearance all day. I'll be testing 155s on my next bike and if I hate them I'll write back Big Grin
  • 3 0
 hips even doesn’t translate into more stability imho. wider stances = stability. a bigger leverage arm = more stability. Shorten the arm in a lever, and it becomes more twitchy.
  • 2 0
 Other than reducing your ring size to compensate, you also have to raise your post for full extension climbing. I noticed this when I dropped from 175 to 165 this year, and I do feel noticeably "over" the bike, though for climbing it doesn't matter so much. However, something to keep in mind.
  • 3 0
 Bike Industry- Whatever you are using now is bad, whatever we are trying to sell is good, we have no reason to lie. 155 cranks are the 840mm bars of 2022. Most people should be on 170's, smaller or bigger is for outliers.
  • 2 0
 I'm a short guy and I'm all for shorter crank availability, however just looking at that diagram it seems to me you would have more stability on longer cranks, the closer your feet are together the easier you are to push over. I want shorter cranks mostly to help reduce pedal strikes going uphill on techy terrain.
  • 2 0
 The cadence you feel good at individually can be influenced to some degree by training at different cadences keeping power output constant. This requires indoor training imo in order to stimulate different muscle groups at different cadences. Then maybe higher cadence on shorter cranks results in same power output a n d equal heart rate compared to lower cadence on longer cranks.
  • 5 0
 "Do Not Remove". I like challenges.
  • 1 0
 I'm 6'1" / 185cm and really love 165mm cranks. After running 175's forever and having 170's on my other bike, the 165 is really comfortable on the knees, seems to get up to speed quicker and the higher cadence keeps me from blowing out my legs on techy climbs. The extra bit of clearance with modern low BB's is pretty sweet. It does affect seat height though—have to put another 10mm spacer under the stem as well.
  • 5 0
 please won't people think of the single-speeders
  • 2 0
 I was just thinking how awful this would be on a single speed.
  • 4 0
 I have a bike with 165, one with 170 and a road bike with 175 and I notice absolutely nothing.
  • 5 0
 And that's a pro for even shorter cranks. If you did ride in places where pedal strikes are inevitable, you would notice. And the fact that you don't notice at all in the pedaling/riding aspect means if you did have a want to minimize strikes, shorter is an easy decision.
  • 2 1
 @justinfoil: when the climbing gets technical I’d probably walk
  • 2 0
 @makkelijk: you're doing it wrong
  • 4 0
 Maybe we can shorten the cranks all the way to small pegs, and put a motor on the bicycle
  • 4 0
 Just put Canfield 155mm cranks on my bike: I’ll never go back! All benefits, no downsides for me at least.
  • 3 0
 had them good few years myself. Wouldn't change now.
  • 1 0
 It does make sense in terms of keeping traditional hip angles with seat tube angles so much steeper.
And being more forward does make sense in terms of balance with how much longer frame reach is.
And shorter makes sense with lower bottom brackets.

So if all other things are equal (and I'm not arguing they are or aren't), this otherwise makes good sense in keeping up with frame design.
  • 1 0
 Why would you be more forward with shorter cranks? You have a narrower stance which makes you taller on the bike but that should just give you more freedom of movement.
  • 1 0
 @ashmtb85: your back foot at its furthest from the handlebars (9 o’clock) is closer to the handlebars.
  • 1 0
 9 o’clock on drive side.
  • 1 0
 @pbandjam: true but it's balanced out by your front foot being closer to the BB with a shorter crank at the 3 o'clock position. Your fore aft balnace shouldn't change
  • 1 0
 @ashmtb85: it is very subtle but for things like jumping your back leg will be straighter. Of course your front leg is further back, but if it’s more bent it’s not the limiting factor.
  • 5 0
 As long as I can route 'em through my headset...
  • 1 0
 What crank manufacturers should do to sell these is offer a demo set. It’s expensive to buy a set of shorter cranks only to find that the taller saddle position requires a taller bar etc. that’s a lot of cost to find out that you don’t care for short cranks. I’d love to try it though. But as others said, I think you’d want a frame with a lower bb drop commensurate with the shorter crank. Lower cg from more drop would be a positive.
  • 1 0
 I rode 155mm Canfield cranks with a 30 tooth chainring + 10-42 cassette in the Northeast for 4 years. Moved to Colorado and needed a lower gear. Tried 28t cr and didn’t like the feel. Switched to 165mm cranks with a 32t cr and 10-51 cassette. Found my sweet spot. I won’t go longer than 165mm crankarms, but am probably not going back down to 155mm.
  • 2 0
 So your saying there is a "sweet spot" for all on handlebars too? and frame size? The real math/science is a question of if you want stability or maneuverability more from your crank length, bar width and frame reach.
  • 2 1
 There's no quicker way to make my legs feel dead (like riding the next day after a mega ride), than 20mm less leverage/mechanical advantage per leg.

Now... on an eBike it makes sense. And with the direction eBikes are going with the likes of that TQ motor... I may actually own an eBike in the next 5 years.
  • 3 2
 Hope: Science
Reality: Our marketing team

The fact, is that everybody has different length legs, different amounts of flexibility and different sized feet, and therefore require wildly different crank lengths. Shimano produce cranks for their world tour teams in almost limitless incremenets for this exact reason.

If you turn an ignorant blind eye to all the well documented facts about bike fitting, sure, everybody needs 155, but otherwise it's just absolute nonsense.
  • 1 0
 I'm struggling to understand how shorter cranks (feet would be 8.8% closer together when descending as compared to 170mm cranks) would have any meaningful impact on your "hip rotation".

At my local gymnasium, I am regularly engaged in activities like heavy, weighted lunges, where my feet are nearly 3' apart, combined with 170 lbs of added resistance and knees/legs articulating asymmetrically. Low an behold, my hips are scarcely rotated, even in this extreme condition.

Now, what I would buy is that shorter cranks would allow frame designers to lower the BB by 10-15mm, which would absolutely have an impact on trail performance.
  • 1 0
 Alright I'm convinced. I love me a sweet spot, so if by any chance I need to get a new frame and they are all too low in antisquat, I'll reduce both chainring size and crank arm size to get my preferred antisquat characteristics.
  • 1 0
 All I know is that nothing gets me through a long day of big climbs more than the technique of standing up, usually shifting up a gear or two and dropping my body weight on each slow pedal stroke. Maintains the same speed I had while sitting, gives my glutes a break, and slows the heart rate. Short crank arms feel like shit for any pedaling other and sitting and spinning.
  • 1 0
 I went from 175 to 165 and didn't notice anything other than fewer pedal strikes. I actually went up 2 teeth eventually, but not because I felt my power was negatively impacted. My main concern was that spinning too fast with flat pedals would cause feet to lose contact, but it was a non-issue.
  • 1 0
 A lot of things, if not all things, could be opimized in size rider to rider.

Obviously, my legs at 6'4" do different things to someone whos 5'nuthin. We ride different frame sizes, so why not anything else?

annoys me that a taller rider just gets their seatpost extended (basically), so where a shorter rider is balanced centrally on a bike, a taller rider is sat on top of it, weight pushed forward over the bars more. This was massively mitigated with the advent of longer travel 29ers. A few companies have dabbled in connecting wheel size to frame size, but i think it should be the norm', along with bar width and crank length.
  • 1 0
 Done! Bought a pair and fitted them yesterday with smaller chainring (oneup oval) and rode today. To be honest I was a bit distracted at start of ride and had completely forgotten that I’d changed - new trail so a lot going on. They feel completely ‘natural’ and the 170s will be on eBay as soon as I get back from Scotland
  • 4 0
 Buy cranks based on your inseam and riding style. It's not rocket science.
  • 1 1
 What does riding style have to do with it? If there is no performance difference, might as well as go short and get the benefits. What are the benefits of longer cranks?
  • 1 0
 @justinfoil: It feels very different to me during downhill riding, the longer cranks don't allow you to move around as much on the bike
  • 1 0
 @IsaacWislon82: That's a benefit. No one can tell why anyone would want to stick with longer cranks.
  • 4 0
 usually too worried about staying on the bike to consider crank sizes...
  • 4 0
 Or you could get the Canfield's for a bit less.
  • 1 0
 How comes that having your feet less spread apart gives you more stability?
I switched from 175 to 170mm cranks and will never go back, but I tried once 165mm and everything was just too twitchy.
  • 4 0
 The truth is the sweet spot is whatever comes stock
  • 3 0
 My buddy Darrell CNC'd me some 139s a couple years ago and I haven't looked back. #shorterisbetter
  • 4 1
 Bored industry needed something, anything to sell, so here we go with a solution screeching loudly for a problem.
  • 1 0
 I wanted Canfield 160s but they were out of stock. I was going to push send on the 155s last night but hesitated. So... Just went a bought a set of Canfield 155s before they sell out Big Grin
  • 1 0
 Ive been running 165mm cranks on 2 of my bikes for about a year and a half and I love the length. It does feel strange when jumping on an xc bike with 175mm cranks though. :-P
  • 2 0
 I have been riding 154,5 mm cranks for years and they have been awesome. I would not go back to SUPER long cranks (155 mm) ever!
  • 1 1
 My son's BMX race bike has 155mm cranks on it. I have a BMX race bike as well and I run 175mm, down from 180mm and I'm 5'7", and I'll put money on the line that I can spin faster on that than 90% of PB readers on those cranks. I'm not buying into the BS--there is a noticeable difference in torque from a 20mm shorter crank arm. Maybe if you have a dedicated park bike, this makes sense, but anytime you have to pedal anywhere that requires a fast application of force, I'm questioning anything shorter than a 165mm.
  • 1 0
 Yes, nice work! I’ve got pretty long legs and prefer 165mm cranks (to 170 and 175 - haven’t tried shorter still) so shorter ones are obviously needed for 80%+ of the population but hardly anyone makes them.
  • 3 0
 It feels like 51% of the industry is posturing new products, for ebike applications.
Are short cranks trending in XC???
  • 1 0
 No, Nino runs 175s
  • 1 0
 Canfield cranks, as short as 150 for $199 including Bottom Bracket, DH rated. These seem on the expensive side for aluminum cranks. I am a big fan of shorter cranks on all my bikes.
  • 1 0
 Clearly what we need is electronically activated cranks that can change length at the press of a button. SRAM - get on it - you could sell an overpriced battery for each crank
  • 1 1
 Apparently I'm some kind of freak, I should be in a circus. Because I put 170s on my bike from 175s and could tell a difference when climbing steep stuff immediately. I understand the physics that if you are on a trainer or riding a road bike the crank length can be compensated for by higher RPMs but what about when you are at max effort on a steep climb barely turning over the cranks to grunt up a section of trail? What happened to me was I couldn't push has hard on shorter cranks. I was climbing sections of trail I have done a hundred times in a lower gear. than with the 175s How is that not slower? It sure felt slower. I gotta call BS on putting a 28T chainring on the front and saying you are going just as fast. No way are you compensating by increasing your RPMs up an out of the saddle super steep punchy climb. Also, how many XC racers are running short cranks? I'm not an XC racer and I do have 170s on my park bike but for a trail bike I'm keeping my 175s. You all drank the kool aid IMO.
  • 1 0
 Why shorter cranks are likely better, lots of science as well as professional opinion: www.singletracks.com/mtb-gear/are-mtb-cranksets-too-long-for-a-lot-of-riders-they-might-be
  • 1 0
 So the article quoted in your link states "test subjects ride a stationary bike with adjustable crank arms" "average power output for each length. Martin found that the max power output of the test subjects only varied by about 4%" I have read this article and as I said above on a stationary bike this makes sense. I don't ride a stationary bike however. See my above comment.
Another study quoted in the link above for "female XC riders. Macdermid found that riders reached their peak power nearly 1 second quicker on 170mm cranks than they did on 175mm cranks." This was also done in a fitness lab on a stationary bike. iAlso female XC riders have shorter legs on average than your average male. So this could easily be a confounding variable that was not take into account.

I will grant that shorter riders may benefit from shorter cranks. I'm 6' tall with a 36" inseam so for me I don't get knee or hip pain from spinning 175s but I see how some people could. Less pedal strikes would be nice. shorter cranks hit rocks less. If you like shorter cranks I'm happy for you. I am interested in sharing peoples experiences with different crank lengths on pinkbike. I think the current science does not represent real time riding conditions and thus it's conclusions are incomplete at best. I think people should have a wide variety of crank lengths to choose from. It's just not as simple as 175,165 or 155 are best.
The article you posted a link to concludes with "Don’t let others decide what size cranks you should use." I agree.

Lets get Levy back on the impossible climb on the same bike with different crank lengths for some real pseudoscience.
  • 1 0
 @Dookiedoodle: "Lets get Levy back on the impossible climb on the same bike with different crank lengths for some real pseudoscience."

Hear Hear!!! Smile

Yea, I basically agree with you, and ultimately choice is good. I only shortened mine on one bike that was really bad with the strikes, not for any knee or efficiency issues. With todays low BB and big BB drops, designing around shorter cranks with the knowledge that they likely won't actually cause issues, could be a great thing.
  • 1 0
 I have noticed a slight leverage improvement in longer cranks especially when doing a lot of climbing. However, the shorter cranks does have benefits like less pedal strikes, lighter, stiffer, and better fit ergonomically.
  • 3 0
 I sure Hope they are right!
  • 3 0
 Remy Morton joined the chat...
  • 3 4
 Anything less than 170mm feels like I'm riding a child's tricycle up the trail. Run proper sag and pedal strikes are a rare occurrence for me with thin profile pedals. Guess it just depends what type of trails you frequent too, but I feel more comfortable 170-175mm
  • 2 0
 i remember people when people were putting 180mm cranks on their mountain bikes...
  • 3 1
 It's a nice way how to save some material while ask for more money. Well done. I'd try them anyway
  • 4 1
 Here we go, crank sizes are the new wheel sizes...
  • 2 0
 Breaking news: Perfect crank length found to be 155mm, signed Peter Dinklage.
  • 1 0
 I see the benefits of a shorter crank, like weight savings, more ground clearance, and more durability, however, wouldn't a shorter crank have less leverage on the chainring?
  • 3 0
 Pick a crank length and be a D about it.
  • 1 2
 1 running a smaller chainring means you’ll be using more of your cassettes smaller gears which in turn makes your dérailleur clutch pretty much useless.
2 your 12 speed cassette will become redundant because in the easiest gear you’ll be spinning like a cat on acid
3 smaller derailleur cages could make a comeback - a positive
4 - 10 speed even 9 speed cassettes could make a comeback - positive
Personally I’ll sticking to 165mm & 34 tooth chainring
  • 1 0
 Nothing new... Canfield have had short cranks for a while now. I've been running 150mm with a 34T for the past year and it's been great.
  • 1 0
 I'm 6'2, went to 165's on the road and I can now make tighter turns while pedaling with absolutely no compromise. Anyone want my 175mm 5 yr old white industries M30s..
  • 1 0
 Going from 175 to 165mm was pure bliss. Now I still get away with 170's on my trail bike, but 165's on an Enduro/Gravity bike is a must.
  • 1 0
 I got rid of my 165s because they just felt too different to all of my other bikes running 175s. Felt weird every single time I rode that bike and gave me knee pains.
  • 1 0
 I want the elliptical version. And I'm already running a 20T. Where do I find a 16T? I don't think you can even find a 20T anymore. They were made by a one man shop.
  • 3 0
 Of course they are...
  • 1 0
 Sadly it's really hard to get shorter cranks than 165 mm... But yea, I've been swapping every bike I had to 165...
  • 1 0
 Canfield all day!
  • 2 1
 Ahhh yes...we all corner with our pedals completely flat...fake innovation still flowing strong with cycling
  • 1 0
 Maybe you should try it more. It also means you can drop the BB and still not hit stuff when your outside pedal is dropped, so they helps all cornering, even if you are exclusively a pedal dropper.
  • 2 0
 It seems a bit odd to offer 155mm but not 160mm
  • 5 0
 Did you miss the part where they said 155mm is the "sweet spot"? In theory, Hope should stop producing other lengths of mtb cranks if this is actually what they believe.
  • 1 1
 @thisc*nt: one sweet spot for somebody 4'9" or somebody 6'4" ??
Not convinced
  • 1 1
 @naptime: phew! I was concerned that you were until I saw this. That's a weight off my shoulders.
  • 1 0
 Nothing new in 155mm size I've been running canfield brothers 155mm as years on my dh bike.
  • 2 0
 180's for life. Long legs matter...
  • 2 0
 2025 mullet crank be introduced
  • 2 0
 Is this a result of so much 'lower and slacker' 'evolution'? And mullets?
  • 1 0
 So if I read that correctly if you go with 155mm cranks you should run a 28 tooth chain ring ?
  • 1 0
 Yes, but only if you are currently on a 175 crank with a 32t ring. Or, you know, run whatever you like. That's why I have a bike with gears.
  • 2 0
 Hope Say Their $365 Cranks Are 'The Sweet Spot'
  • 1 0
 Does that mean the dropper post must be raised higher to compensate for the reduction in length?
  • 1 0
 Well my 2020 Ransom came with 175mm I switched to gx 165 32tooth 29er .so comfortable.love the short cranks
  • 1 0
 Isn't it like the chocolate brand that makes tests and proove chocolate is good for your health?
  • 1 0
 I swapped from 175mm to 165mm long cranks other then less pedal strikes I didn't notice a bit of difference.
  • 1 0
 My girlfriend told me I can t buy these. " if you can find mine, you cant buy another" . bruh...
  • 1 0
 I could stand to lose 10mm of crank on my Patrol MX... 165mm not short enough if there's anything resembling a rock.
  • 1 0
 Maybe should do a study that correlates middle leg length to crank length. Cm-Cm.
  • 1 0
 Want to get some for my significant other, who is 5 foot nothing. Anyone actually have them in stock yet?
  • 1 0
 Anybody tried 145mm cranks?
  • 2 0
 Best crank for shagging?
  • 2 0
 Depends on the terrain
  • 1 0
 I’m Hopeful there are more brands that follow
  • 2 1
 Actual real science or the last few years "The Science ⟨™⟩" ?
  • 1 0
 Sweet! Just not the price!
  • 2 0
 Shrinkflation......
  • 1 0
 (Glances at his SRAM cranks while holding a hacksaw.)
  • 1 0
 6’3 tall with a BMX background waiting for a 145mm crank
  • 1 0
 Nope. I prefer to have some actual torque in my pedal stroke....
  • 1 0
 Did I miss the Ford vs Chevy jokes?
  • 1 0
 two quicks links and no one says nothing about it
  • 1 1
 Are they gonna make 26t chainrings as well? If not, I won't get up the hills with my 11sp setup.
  • 1 0
 Laurie Greenland has been running them with Saint stickers on this season
  • 1 0
 Run 155 Canfield cranks on my dh bike LOVE IT..
  • 1 0
 This is not new, Canfield knew this forever ago.
  • 1 0
 I was hoping for 156mm.
  • 5 0
 Flip Chip cranks to give you the final few mm of adjustability - you read it here first!
  • 2 0
 @eddieantifreeze: axs flight attendant dynamic length cranks, you read it here first!
  • 1 0
 @spencer-funk: dang! They beat me to it - I guess I won't be going to the patent office today then!
  • 4 3
 I still miss my 180's.
  • 2 0
 I don't miss mine, because I run 180's on all my bikes.
  • 1 1
 ah the new "saints" finally revealed
  • 1 0
 Yeah, nah... nah
  • 2 5
 I’ve been saying this forever: the shorter the crank the better.
  • 5 1
 Reaching the obvious conclusion that 1mm cranks are the absolute peak of performance. Very tiny little circles. Think of the ground clearance! Seriously, I do think these are a much needed option for people with short legs, children, small women and what not.
  • 5 1
 @SunsPSD: I’m thinking pegs and a motor.





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