Boone's Aluminum Cranks Look Like They're From a 1950's Sci-Fi Film - Pond Beaver 2021

 They have what looks to be a proto crank that is stamped clamshell stainless steel that is then laser welded together. Much more interesting than just another machined billet crank. They are also working on a ti version.

www.instagram.com/p/CMNU02QlVpd

www.instagram.com/p/CMSdrA9FHzL

 @shirk-007: hollow stainless would get my attention. But these particular cranks don’t.

 @wyorider - your point C seriously doubt you have anything on 175 cranks. If anything it's roadie science. A flawed one, since top teams don't give a damn. Your logic on longer cranks more rocks strikes is flawed too. Longer crank arm = more power per pedal stroke = lower cadence. Less pedal strokes less chance to hit rocks, easier to time pedal strokes. There is no excuse to hit rocks on climbs. It is 99% riders fault.

If we go away from rocks and just spinning - it is highly individual, based on genetics, being trained in particular way or just being used to something. Shorter crank arms make you pedal faster, (higher cadence) and people who are generally more on endurance side of things, prefering higher cadence will favor shorter cranks. They make it easier for you to press fast on pedals from lesser knee/hip angle. However one cannot say it is hard to pedal fast on long cranks. BMX racers pedal incredibly fast on 180-185 cranks.

Nino Schurter uses 175mm cranks. Go rewatch the video where Mike Levy climbs this loose gravel climb with him. Levy spins fast and since he pushes faster he cannot modulate power well. If you look at Nino, yes he is a monster, but he also takes his time to push on those pedals on a harder gear. I'd argue it's more of a technique and being fine with low cadence in this situation. Then look at Levy on impossible climb attempts - he is doing it wrong. He spins out in most cases because he pedals too fast. Shorter the cranks the less leverage, the less power you can put through a single stroke, you cover less ground per each stroke... it's like starting a car up a hill in winter on snow or ice - you may need to use 2nd gear to start rolling. Except with short cranks you can't have it. Grip and rock strikes are non existent on road bikes, where ALL pedalling science comes from. And here the short crank argument is lost as well. I know for a fact that in BORA Hans Grohe team riders of similar heights will use different crank lengths, often oscilating between 170 and 172.5, in most cases 172.5. From Sagan at 184cm to my hubbie of my sister in law Cesare at 170cm. but well then they hate Disc brakes so they aren't always the sharpest about everything

If you are a high cadence kind of person then 165 cranks may be great for you. For technical climbing they are detrimental in every possible way. If only because you hit rocks and roots all the time, and you can't really down shift because you lack leverag to push the hard gear or at least make it very taxing for yourself. I keep 165mm cranks on my DJ and if I had a DH bike I'd use 165 too.

 @justwaki: www.trainingpeaks.com/blog/the-benefits-of-reducing-your-crank-length

Here you go.

And a sample size of one (very good) rider proves nothing.

And yes, 5mm extra clearance dramatically reduces rock strikes.

And no, it’s not really a “highly individual” thing. Even tall riders with long femurs benefit from shorter cranks.

Try some.

 @justwaki: get a life I hate scrolling down your paragraphs of bullshit.

 @wyorider: Well all professional cycling world is missing out then... given they are all indoctrinated by Italian and French scientists doing more reasearch than this dude. Who obviously doesn't take grip and pedal timing into account. Nope... he may stay in the lab. Good times for that.

But I can remember our conversation in case top racers start using shorter crankslike they started using fatter tires (against the lab) and frames with some level of damping (agianst the lab). I'll get back to you if you are right. Read on Types of muscle fibers meanwhile and why track/BMX racer does not look like Froomie, just like how much their power outputs differ - max output as well as sustained. Why soccer player looks differently than NFL Player and differently than a marathon runner and differently than a sprinter even though they all fricking run. Why we generate different levels of torque from different cadences

 @justwaki: false. Bike racers are often deeply conservative and superstitious about their component selections. That’s why they were reluctant to use full suspension bikes, disc brakes, tubeless tires long after those technologies had been proven to be superior. Ditto for droppers even to this day for XC.

Accepted crank length per discipline isn’t based on any research, just hearsay from over 20 years ago.

The only cycling discipline where crank length has a logical reason is track racing, where longer cranks would mean pedal strikes on the banking. And even the biggest track racers put out big watts on 165s.

 @wyorider: sorry this article isn't even lab, this is some dude interpreting someone's data, telling a fricking incomprehensible analogy, in a way saying that energy exertion doesn't change, then giving an example of tall dude saying short woman should have shorter cranks, off course supporting his OPINION of short cranks, 145mm cranks don't exist bladi bla, as if fricking 195-210mm cranks existed. READ what you are reading he basically said that what he got from the research papers he read, is running short cranks is like riding on a shorter track... and then he says that leverag doesn't matter in the whole picture... except TT bikes have almots exact same gearing and outer diameter of the wheel so the only variable is fricking crank length. Sorry, this OPINION article, no just no...

 @wyorider: longer crank > more leverage to push harder gear > ability to push harder gear in certain locations > more distance covered per pedal stroke > better modulation > less chance to hit a rock (easier to time a pedal stroke) and spin out on an edge of slippery root or rock.

When I rode my DJ on 175 cranks I could easily ride up the hill to dirt jumps on 34t to 15t rear. On 165mm I have a hard time on 32t, so well, yeah... leverage ain't matter... or maybe it does

If you just sit in the saddle and spin fast through a rockgarden expecting to not hit anything, using momentum as the only way to get up = sure you have a hard time on longer cranks. Learn from Nino, don't ride like Mike Levy. Spun out on wet rocks being on 50t cog rear and possibly 32t front ... well no fkng waaaaaay

 @wyorider:

Any other resources on this? News to me and I can use any advantage I can get.

 @ryan77777: www.redbull.com/us-en/how-long-should-mtb-cranks-be#:~:text=Shorter%20cranks%20can%20help%20with%20acceleration&text=The%20results%20showed%20that%20there,accelerate%20up%20to%20maximal%20power.

 @ryan77777: Most studies show that conditioning is the most important factor in how hard you can pedal. Skills need to be developed through practice (skill drills/sessioning challenging features). A shorter crank isn't a miracle or magic bullet, but especially as bottom brackets have gotten lower, trails have gotten burlier, and riders are more likely to be on full suspension bikes that sit EVEN lower when the suspension compresses, a little shorter crankset helps reduce pedal strikes (a little). 165mm may feel too short (they do to me, except on a track bike and I haven't been on a velodrome in 17 years) but 170s still give plenty of leverage and a bit more forgiveness.

 @wyorider: Shorter def is not a magic bullet. I could and would never ride 165mm. I can already tell the difference between my current 170s on my 2020 bike from the 175s on my 2015 bike. I wouldn't go back because I do appreciate the pedal strike issue on the modern bikes, but I sure miss my 175s. Just like the feel better and still think I can get more leverage and torque. Other's mileage may vary.

 @wyorider: Step 1: Yeah! Pick a crank length and be a dick about it!

As much as I hate to take Waki’s side on anything... are you really reading the articles you’re posting?

They are not remotely as conclusive as you claim. They’re a continual stream of “no difference” and “could” when discussing study results. The training peaks article is basically nothing but a rant about the fact that tall and short riders ride similar length cranks, with no MTB relevant claims of superiority for one or another. The other article only identifies one clear benefit (faster ramp to peak power) and following the link to the abstract leads me to question whether this is just an artifact of the test design.

None of those articles acknowledge that individuals differ from the average and may benefit from different setups than the averages reported in studies. And they have absolutely zero evidence to support your claim that “Even tall riders with longer femurs benefit from shorter cranks.”

 @Blackhat: but modern bikes all have hella low bottom brackets. The articles I’m posting suggest that crank length isn’t a huge determinant of performance.

So......if we’re riding modern bikes with the bb close to the ground, and crank length has a minimal (if any) effect on performance, then yeah, 175s are outdated.

Might as well not be snapping pins or grinding cleat retention bits as much.

 @wyorider:

They suggest that they’re not a huge determinant of performance among a POPULATION. None of the linked articles said anything related to the variation experienced by individuals. And come to think of it, a great way to find “no difference” in a scientific study is to have a ton of variation so that the P values are high. So if some riders performed better with long cranks while others better with short cranks, you could easily get articles saying the study found no difference.

You haven’t even attempted to show how much pedal strikes affect performance. You just take it for granted that pedal strikes are a major issue that all riders should optimize for. Nor have you considered that factors like better leverage or the ability to put out more controlled power as mentioned by our dear waki might offset the pedal strike risk.

The problem here isn’t that you’re wrong. Maybe short cranks are better. But your confidence and aggression are 9’s while your evidence is a 2.

 @wyorider: also:

“all the current biomechanical research shows that 175 cranks are inferior to shorter ones, not to mention that longer cranks=more pedal strikes.”

That was your statement. Your claim was very clearly about biomechanics, with pedal strikes as an afterthought. And if very clearly said that one was found to be better than the other.

Don’t try to weasel out of it now.

 @Blackhat: I didn't find him aggressive at all. He posted some sources, it's still a sign of progress in human interaction on the internet. it's me who was a bit of an ass I think even though I stand by my opinion. I value such discussions a lot.

My biggest issue with first article is that there is an obvious bias of the writer and he believes all humans are built the same, only height changes. By this measure we could say that Olympic lifter could become an Olympic Marathon runner if they only chose this path when they started. Second article is better in a way that it is a bit clearer that it is an opinion. Acceleration point is valid at least theoretically. Initial acceleration is indeed better on short cranks I also belive they are a bit more comfortable on long rides. I could add that manualing, bunnyhopping and generally hip drive related movements, standing on a "shorter" platform is beneficial. For people who drop pedal a lot for corners in rough terrain, it's also a factor.
But they suck in low cadence scenarios and don't provide as good balance in steep climbs. I have lots of that in my area, but in my home town with most climbs being fire road climbs it would never be an issue.

Cheers!

 @justwaki: I don’t think he’s personally aggressive (eg insulting others), but I do think he’s stating his position aggressively and leaving no room for debate. Which is fine by me when the evidence supports it, but that’s not the case here.

On top of your list of pro/con situations for each crank length (which is good) we can add that some riders just don’t have the coordination, muscle fiber or skills to spin smooth power on smaller cranks. Perhaps such a rider could make an effort to remedy the situation, but for an average rider with typical weaknesses that would be like 146 on the list of mountain bike skills holding their riding back.

 @Blackhat: Coordination is a whole another bag of worms. it can be said both ways. I believe that there are even fewer people who can spin like BMX racers, 120+ RPM on 180-185 cranks. I did however get much better at spinning fast on short cranks, in fact all cranks, it's a matter of getting used to, with minimal differences in end result based on genetics/ training adaptation.

I believe though there is another problem (to open another can of worms). Most people think they should pedal at high cadences at all times. The holy 90RPM of the road world sure made it's way to MTB in a slightly uneducated manner. The problem is that folks just shy away from low cadences (and standing pedalling!) thinking they are inefficient and draining. It's another adaptation one can make, especially with help of resistance training. Almost all beginners I see in the woods just spin into stuff counting on generated momentum. yes there are some amazing riders like Ryan Leech or Thomas Oehler who spin fast and then hop a lot, but they are outliers and an educated eye can quickly spot that their body composure makes it very likely that they are fast spinners by genetics, as opposed to beefcakes like Rude or Graves.

I bring up this example again. The episode of Humbled with Levy VS Schurter. I claim that if Mike only cranked on a harder gear (was more used to pushing against that hard gear) like Nino, he'd get to the top. But having lower gear and not being able to modulate power equally well he was wasting energy with his wheel spinnig out here and there. He just tried to power through by maintaining his momentum with not much sensitivity for what his rear wheel does. And I would take it as staged if not his attempts at impossible climbs in Field Tests, showing same technqiue. Off course he'd be equally spent, or maybe more, but he'd make it to the top.

youtu.be/IP90fFtO94c?t=135

 Man you sure know how to have fun

 @wyorider: If reducing crank arm length is so beneficial (aside from possibility of reducing pedal strikes) why do we have crank arms at all?

With your logic I'll be better off if I swapped to 145mm cranks from a children's bike? LoLoLoL