Ask Pinkbike: Long-Travel vs Short-Travel Trail Bike, Measuring Fork Stiffness, Heavy Tires or Inserts?

Apr 5, 2021 at 9:40
by Seb Stott  

Here at Pinkbike, we get inundated with all kinds of questions, ranging from the basic "Can I have stickers?" to more in-depth, soul-searching types of queries like if you should pop the question or what to name your first child. Ask Pinkbike is an occasional column where we'll be hand-picking and answering questions that have been keeping readers up at night, although we'll likely steer clear of those last two and keep it more tech-oriented.





Can I set up a 160mm bike to ride like a 140mm bike?

Question: Jhomas.toseph asks on Instagram: If you've got two bikes with the same leverage curve, but one's short travel and the other is longer (say 141mm vs 161mm travel) would it be possible to replicate the feel of the short travel bike simply by increasing the spring rate on the long travel bike? I'm trying to choose between the Privateer 161 and 141, which look to be almost identical apart from the travel numbers. I don't ride flat out fast trails very often, so would generally prefer a firmer more supportive ride. However, I'm wondering how much of the short travel feel I could achieve on the 161 by running higher shock/fork pressures, whilst still having the option of a plusher ride with deeper sag for bikepark/DH laps. Any help would be very much appreciated! Cheers!

Privateer's 161...
Privateer 141 Photo Kifcat Shaperideshoot
...and 141.

bigquotesI think the basic answer is yes. If you were to run 26% sag on a 161 and 30% sag on a 141, both will have 42mm of sag. And barring any significant differences in the leverage curve or the shock, that would mean they'd have the same spring rate. Obviously air shocks are non-linear so there will be a difference as the 141 gets towards the end of its travel, but in the normal "pedaling region" (say the first 100mm of travel or so) the wheel rate and therefore the feeling of support vs harshness will be pretty similar. You could add volume spacers to the 161 to get it to feel almost identical. You may never use all the 161's travel when set up like this, but that's not necessarily a bad thing - you could just think of the last 10-20mm of travel as "for emergencies only".

Normally, the problem with running less sag than the bike is designed for is it will give you a higher sagged bottom bracket height and steeper dynamic geometry. But that may be exactly what you're after for flatter, less demanding trails. Plus, the Privateer 141 and 161 have near-identical bottom bracket heights and head angles, so you'd be getting the same sagged geometry anyway if you ran the same number of millimetres of sag.

One difference is the effective seat tube angle, where the 161 measures 80- degrees and the 141 measures just under 79-degrees. If you ran both bikes at the same percentage sag, the extra travel of the 161 would cause it to sit at about the same angle once sagged, but if you set the same absolute sag, it'll be a little steeper. That's not necessarily a bad thing though, and you can always slide the saddle back on the rails if you find it too steep.

Personally, I run about 28% sag on the 161 and I find it to be a very comfortable climber. The steep seat angle makes it feel very purposeful on steep climbs and the high anti-squat suspension means its efficient under power too. It's no cross-country racer, but it pedals well and the 141 is barely lighter. 





What exactly is meant by fork stiffness?

Question: @PDXooo asks: Please help me understand something. When people speak of fork stiffness (due to stanchion diameter etc.) what are they referring to exactly? Is the flex occurring where the stanchions AND crown meet, or stanchions to lowers...?

bigquotesGood question. Manufacturers and reviewers often don't specify exactly what they mean by "stiffer", but you can measure fork stiffness in three ways: Fore-aft stiffness (how much does the axle move back and forth for a given force); torsional or steering stiffness (how much does it twist along the steering axis if a torque is applied between the axle and the stem); and lateral (how much does the axle move sideways for a given lateral sheer force). Manufacturers sometimes choose not to specify which they're referring to in order to make their fork seem better. For example, inverted forks are usually stiffer fore-aft but less stiff laterally and torsionally; their manufacturers occasionally forget to mention these last two metrics when talking about stiffness.

Where in the fork chassis most of the flex occurs is hard to answer, but I think the basic answer is "everywhere". Forks are carefully designed using Finite Element Analysis to maximize their stiffness-to-weight ratio, so it wouldn't make sense to have one component in the chain connecting the axle to the frame that was much stiffer - or much less stiff - than all the others. If you look at slow-motion footage of forks flexing, there appears to be some visible flex in all the components (crown, stanchions and lowers).

Fox and RockShox have both released forks with 38mm stanchions for extra stiffness.



Heavy inserts or heavy tires?

Question: A nice chap I got talking to on the trails a few weeks ago asks: I get punctures occasionally. Should I bother getting a set of inserts like CushCore, or just heavier-duty tires like DoubleDown casing ones instead of EXO (which has a similar weight penalty)?

Cushcore review
Inserts can prevent punctures, but so can thicker tires. So which is best?

bigquotesIt depends on what's causing you to puncture. If it's sharp rocks like flint or slate cutting a hole in the casing, an insert isn't going to help at all. If it's pinch flats, then an insert should reduce the risk of those dramatically, but I can tell you from bitter experience that they're not 100% effective. And remember, if you do puncture and you can't fix the tire with a plug, you'll have to carry the sealant-soaked insert home with you. An insert should help protect the rim from damage to a greater extent than a thicker-casing tire, but again, I can tell you this doesn't always work - I once destroyed a SRAM Roam 60 carbon wheel in the middle of an Alp with CushCore installed after hitting a hidden rock at speed.

The difference in weight between a Maxxis EXO and DoubleDown tire is about 200-250g, while CushCore weighs about 265g per end in 29". However, the thicker DD casing doesn't just add weight, it will also increase rolling resistance. This is because the stiffer sidewall saps more energy when conforming to the ground at the contact patch as the tire rolls along. This difference in rolling resistance is probably more noticeable than the difference in weight between EXO and DD tires in terms of climbing speed. CushCore, on the other hand, is claimed to maintain or even slightly reduce rolling resistance, so the EXO tire with CushCore will likely be a faster setup.

I'd also say that, in the case of CushCore especially, there's a noticeable benefit in terms of ride feel and traction. The tire is more damped, so it skips off the ground less over rough terrain and offers more traction and comfort than a standard EXO casing. A stiffer tire casing will provide more damping too, but with CushCore there's less of a downside in terms of the "wooden" feel over small bumps that you get with stiff tire casings. I've also enjoyed Rimpact's inserts, which offer some of this damping benefit, though to a much lesser extent, at around 100g per wheel. As far as I can tell, Nukeproof ARD, Huck Norris, RockStop and Flat Tire Defender have no real impact on ride feel.

Obviously thicker tires are cheaper than thin tires plus inserts, but some of the more robust inserts (again, CushCore is one of the most long-lived options I've tried) should outlast several sets of tires, and if it saves you from destroying one set of tires in its lifetime, it's practically paid for itself.






178 Comments

  • 150 30
 I find it very curious how many riders experience tire puncture issues. About me : I live in an area with long, fast rock filled trails, weigh close to 200 lbs loaded up, am pretty fast (top 5% of Strava times on just about any trail I do), and I run exclusively EXO casing tires at 21/25 psi (F/R). No inserts or anything. And yet I haven't had a single tire issue in 5+ seasons. Do I need to run less psi? Ride harder? Am I "smooth"? Just find it weird how many PB'ers have tire issues, when I never have any?
  • 395 3
 I mean, you are Superman, right? That cape probably helps out.
  • 19 0
 It probably has to do somewhat with each of the things you mentioned. Knowing a trail also decreases punctures. I would easily go a season without a flat tire, until I started to ride at Big Sky, MT more. I wouldn't even bother bringing a single-wall tire there.
  • 17 1
 The number one thing that gives me punctures here is thorns, special Gorse thorns that seem to be invisible until the moment of impact and also able to render sealant inert until all the air is gone from the tyre.
  • 5 1
 I find that at 180 lbs and similar skill/speed most of my flats are the result of trying to ride like the 50to01 lads and just blowing my bead out in berms/ruts. I think weight bias has something to do with it too, usually more experienced riders are central on the bike and aren't smashing the back wheel into stuff as hard. I think a lot of it is just luck and coincidence too!
  • 11 1
 At speed on limestone or coarse/
large crystal granite, you'd be grenading tires all day, every day. I weigh 40 lbs less and have to run Double Down (or equivalent) rear tires to avoid sliced casings.
  • 16 1
 I have sliced every exo tire Ive tried. Not sidewall I'll cut them in-between the tread. 28 psi rear 25 psi front and similair build as you. Not gonna lie I hate bringing tools with me. (other than a hex set) So now I just run a DH rear and DD front and have never had a puncture in the last few years. Ive run the same setup on my dh bike for 5 years and kncok on wood have never even flatted. No inserts just basic tubeless setup.
  • 21 3
 If you are top 5 percent in strata you are probably picking the cleanest line. Some people like plowing through things and hitting the rowdier more chunderous lines
  • 8 0
 @superman-4 I have always wondered the same - I think its the terrain we ride (given locations, I'm guessing we do similar trails). I have had a flat once in the last 4-5 years despite weighing 200lb without riding gear, and while I'm probably not as fast as you, I am famous for breaking bikes and parts. I think the rock we have is just a little more... accommodating. It looks sharp and hurts like heck when you crash, but doesn't seem to cut into tyres like it does in other places in the world.
  • 10 1
 Probably just ride very precise and know how to float the rocks really well. Most riders these days are heavy feet and light hands and that's fine for max control but does not really put you in a good spot on rocks and G outs Keep shredding!
  • 16 3
 Ive been wondering this a while as well. I think we got a lot of guys here taking bad lines frankly, 'riding heavy' and I would even argue bad suspension setups that are not doing them any favors on square edge hits.
  • 2 0
 I’m the same way. I run exo and ride very rocky fast terrain and (until a few days ago when I cased a jump and got a pinch flat) have never gotten a flat when riding tubeless. Yet I see so many people getting punctures on my local trails.
  • 20 2
 @MikeyMT: Different folks different strokes you may call it the “bad line” someone else may call it the “fun line”
  • 10 4
 @iantmcg: So fun you hit a square edged rock and get a flat because you should have just jumped over the whole rock garden in the first place Wink
  • 2 4
 @MikeyMT: I like hucking off square edged rocks. Thought honestly the few punctures I have gotten felt real random. Like after all the abuse I put my tires through that was what did it? I mean I have chased people that are real fast before and it is fun for sure but not my favorite kind of fun, I like finding little jobs, making square edge rocks into mini hucks.
  • 13 0
 Something doesn’t add up. I ride in a very rocky area, and all of the fastest dudes are running DD casings, many use cushcore, and we still destroy rims and get flats from time to time.

Maybe it's the KIND of rocks? I'd imagine lots of round rocks, or sandstone, is very different than knife-edge, square-edge, all-over-the-place hardly-any-dirt kind of rocks (which is the case where I'm at).
  • 1 0
 @superman-4 My guess is you pick relatively smooth lines and/or the rocks in your area may not be very sharp. I have never been a rim or tire destroyer in my 5-6 years of riding, and I've spent the majority of those years riding some very rocky trails in the southwestern US. I always figured it was because I'm a pretty light weight guy (~145 lbs ready to ride). Then last year I was riding an unfamiliar trail that had some sharp small to medium sized rocks that were partially covered in leaves and hard to see. I managed to break a brand new Ibis S28 Carbon rim running about the same pressure in the rear as you do, and I honestly didn't feel like I was riding all that hard since I didn't know the trail. Luckily Ibis offers free crash replacements on those rims, which I never thought I'd need and wasn't really a consideration when purchasing them.
  • 2 0
 @iantmcg: agreed. countless times Ive stopped to be like for sure Im screwed and nothing. The flats I get happen after something seemingly benign.
  • 1 0
 @iantmcg: Yea fair enough man. I run Cush Core with EXO casing on my trail bike and its been a while since I've had a flat. on the DH bike, DH casing and cush core...do destroyed rims count as flats? lol
  • 1 0
 @gonebikin143: I with you on this one. The few time I have had a pinch flat, they were do to hitting flat edges at speed and on trails I was unfamiliar with. I have never had a flat on my local trails.
  • 4 0
 3 years on nothing but EXO, only flat was from a broken spoke. I also don't understand how people flat so often. Derailleur hangers I mangle weekly. Everyone's got their vices.
  • 3 0
 What width are your tyres? The difference between a 2.3 and a 2.6 at those pressures is enormous. I am a bit lighter than you and 21/25 on 2.3 trail tyres would be pushing my luck, but safe as houses on 2.4+. If you are on 2.5" or more then I can believe that you do OK, but 21/25 isn't going to give the best grip.
Currently I'm running 13/16 on 2.6/2.4 (with a special insert) and the grip is phenomenal.
  • 1 0
 I wonder the same. I’m the same weight as you and rarely have issues.
  • 2 1
 @superman-4: LOL I guess you are superman and flying down too fast to notice you got a flat before your tires went flat! Are you one of those fella's that yell Strava every time you hit the top or at every segment end? I actually yell out Strava when I see a rider go zooming by at the peaks without stopping - it's just to remind them that this should be done Wink Big Grin
  • 1 0
 @G-Sport: special insert...go on.... also your pressure is crazy low...I thought my 18/20 on 2.5" tires was low.
  • 2 0
 Hope you're knocking on wood
  • 3 0
 @MikeyMT: I’m 2.5 on dh bike
And 2.4 on trail
Both I run 23/27
I’m 185lbs
Cush core on both
DH casing on DH and exo front and rear on trail
  • 1 0
 @MikeyMT: if that's G-Sport George, I'm willing to bet he either designed and/or made it himself.
  • 3 0
 Dude. You just jinxed yourself
  • 1 0
 You sir just jinxed yourself. I am similar, in size, gear and terrain. I went 2 seasons without so much as a trailside flat, last season, i destroyed 4 tires. 2 of them within 2 weeks on install. Just shit luck.
  • 2 0
 I'm heavier that you but experience similarly. I found even with tubeless I'd need to run quite high pressure not to rim strike so I would always trade flat/impact resistance over grip/feel/performance. Now with Tannus tubeless inserts I can run nice previously-unsafe pressures (20-21psi) and still not flat or pinch or rim strike. But I still run EXO+ tires. I rarely tear sidewalls.
  • 16 0
 I weigh 400 pounds and only ride my road bike on double black diamond trails. 5 psi with latex tubes and turbo cotton tires. I've never flatted and I'm banned from strava for being too fast.

(I'm 190, pretty fast, and cant run less than 28psi with double down casing or I'll destroy rims)
  • 3 0
 It's sooooo terrain dependent. Flats were a constant for me when I lived in Arizona. Not an issue at all in Northern California.
  • 3 0
 I weigh a little less than you and I'm not as fast as I used to be, but ditto... the only tire related issue I ever seem to have is needing to add a little sealant once in a while. I like the idea of CushCore but I can never get past the idea of adding any additional weight to my wheels
  • 2 0
 @ljfran2383: REAL TALK
  • 18 0
 @superman-4 I'm nearly the exact same boat except tall and a little lighter- 178. I run the same tires and PSI as you and with sealant have never had a single tire issue since tubeless was invented.

I have a buddy who isn't top 5% like me, he's top 1%. He runs cushcore with DD and blows up two wheelsets a season. Here's my explanation: there is a huge gap between top 5% and top 1%. The twenty or so seconds I've managed to follow him on double blacks have been violent beyond my ability. Those extra seconds come from intense forces and lines that wreck bikes.

Tl;dr 5% on strava doesn't mean Fast, and Fast destroys bikes.
  • 3 0
 Same. I’m lighter than you at 160 but Ican count the flats I’ve had on one hand since going tubeless back in 07.
  • 2 0
 @Mtmw: I think this is the answer. 5% on strava is probably quick but once you hit top 10 for popular trails you're doing things to your bike most riders would never attempt
  • 3 0
 you are what we call "someone with good line choice", very uncommon these days....
  • 3 0
 Exo tires self-destruct in despair when ridden properly over Apennines limestone.
  • 1 2
 Fat old cunt, Still running tubes. Tubes NEVER burp, high pressure by todays standards 26-32 in single ply tyres, always go for smoothing the rough lines. Punctures around 2 or 3 years....... Guess I'm just lucky
  • 2 0
 @jjjared: Yep. The rocks are much different in a place like Phoenix where one can get cuts in the tire between the treads than in a place like Sedona or Flagstaff (or Tahoe area). Places like Phoenix also have tons of cacti/thorns unlike other areas but those at least are more manageable.
  • 1 0
 .... Intant Karma/Sods Law is bringing you flat tyres for the next month
  • 1 0
 US/Canadian bike trails have a ton of work,most videos I watch the trail is very refined and clean,man made thing everywhere.
Trails around Madrid are "natural",we ride a pile a rocks and junk,nobody can work on the trails,it is not allowed.
In my enduro bike I ride DH or DD tires and inserts.I lost the count on how many wheel sets I have to rebuild in the last 8 years,at 145 pounds going reasonable quick.
EXO means nothing here hahahaha. My last EXO tire flat destroyed my rear wheel so fast I have no chance to save it or minimize the damage.
  • 1 0
 @Superman-4: 3 possibilities, your rocks are rounder, your lighter weight, or you need to go faster (saw you crush strava).
  • 2 0
 @MikeyMT:

Yea I’m 175pounds and on EXO 2.5” and I’m currently running 24/28 bc I didn’t my rear rim when I went lower.

I probably need to try some inserts
  • 1 0
 @gonebikin143: I rode Big Sky for the first time last summer. All the local advice was 40 psi or more. My friends and I aired our tires up to 40 in the rear and 35 in the front and had no issues. But man is that place rough! I've no doubt that running the 25 psi front and 30 rear we get away with in the PNW would've been tire suicide.
  • 2 0
 @justinc5716: I run 23f/27r at big sky
  • 1 0
 @jjjared: Yep. I borrowed a new EXO while waiting for a replacement for my torn bead tire and on ride #2 punctured between the tread. That tire now has 6 holes and patches. Ran 26-28 PSI & Cushcore all on familiar trails. Have to love AZ Hawes and SoMo. Most holes were at Hawes where it is relatively smooth.
  • 1 0
 @justinc5716: lol...40 PSI with a tube maybe. Its my local bike park...I'm running 21/23 with Cushcore DH casing. Never had an issue.
  • 1 0
 I'm only 75kgs ish and I almost never puncture, but I'm running fairly burly tyres having learned the hard way that flint punctures lighter tyres round here. And I'm running double Rimpact, and glad I do, as at my last race something sharp flatted my rear tyre and i rode out the last minute of the stage on the insert. 30s later with a tyre plug at the bottom and ready to go again, with only a slight ding in the rim to show for it. Would have been a whole race weekend ruined without the insert.
  • 1 0
 Vittoria Air-Liner anyone?
  • 41 1
 Bottom 5% on Strava, 2 bills, no flats, run continuous track tank treads on my class 8 ebike. Alpine, 12” subs, 400 watts.
  • 3 0
 sounds like you're having good fun
...
at least here, in the comments "department"
  • 27 2
 Cushcore stretches out after 5-6 tyres. Put it in the dryer. It'll shrink back.
@superman #4.
I am very surprised you top 5 everything and have no flats ever, but that's cool. I use dd and cushcore and get no flats, just rips. I'm 80kg. Run 21-24 psi and can ride a bike. With out cushcore my rims last a season. Sometimes less.
  • 19 1
 @solf This is all because that person lives in Calgary and you live in Pemby. I know from experience Pemberton has some of the rockiest rocks I've ever seen. Calgary, Bragg Creek, even Canmore don't compare to Pemberton.
  • 8 0
 My cushcore is significantly looser now. What settings do you use in the dryer?
  • 11 0
 @pcledrew: ...some of the rockiest rocks I've ever seen.

Brilliant!! Wink

I have seen some of those round my way too, you'd recognize them instantly, they are just so damn rocky.
I have named one of them Rocky McPointyRockface..
  • 9 0
 @Piazzano: permanent press... don't want to have iron out the wrinkles.
  • 4 0
 @Piazzano: low. 15-20 min. Check at 10 min just to be safe.
  • 1 0
 @pcledrew: PEMBY!!! the best.
  • 2 1
 @Piazzano: I run 87 psi, 4 clicks of compression and 15 clicks of low speed rebound with no volume spacers
  • 1 0
 100% gonna do this. For maybe the first time ever, going deep on reading comments actually pays off!! You just saved me a few hundred bucks. Even if it’s a joke at least I’ll have a good laugh Wink
  • 2 0
 @OpeSorryAbootThat: I run the same in my rear tire. I have negative rolling resistance.
  • 1 0
 Almost summer here in AZ I'll go leave mine outside or in a car and check the diameter.
  • 2 0
 @rrolly: Nice! I'd share my washing machine settings but I've got a custom tune
  • 16 2
 You all have to check out Tannus Armour. I’ve run all the inserts and it’s the best, half the weight, half the price, and way better feel than Cush core
  • 3 0
 Tannus tubeless?
  • 1 0
 @AvidTrailRider: @milesofpain asks, because there's a Tannus system with tubes
  • 1 0
 I haven't ran Cushcore to say its a "way better feel", but the weight savings over Cush, ease of installation, improved small bump from lower pressures, and pinch and rim protection has me sold on Tannus Tubeless.

I run a Dissector rear currently, and a DD without insert is 1176g and a Exo+ with Tannus is 1103. And I can ride less pressure by 1-2psi. I've certainly put a few dings still in the rear from going too low but haven't flatted when I did.
  • 2 0
 @vhdh666: I know. I'm pretty sure tmtb999 is talking about the tubeless stuff cuz the tube-in one can't be half the weight of cushcore, it's 310 g.
  • 7 0
 I did exo casing + cush core for a while. It's fine but it feels odd having the flappy soft casing vs the firm/damp insert. You can notice the step change when one part of the system is engaged va the other. The tire system feels much better with cushcore + DD. If I had to step down in weight I'd go DD with no insert or exo with cushcore xc
  • 1 1
 Yeah for cornering support you need to keep the tread area from folding. CC helps somewhat but I think you're better off distributing that weight/support across the tread too. A light casing
+ CCPro + low pressure gives the illusion of support by not feeling squirmy in sub critical cornering situations.
  • 2 0
 I think cushcore XC is a good compromise, maybe EXO+ with the XC inserts would be good.
  • 10 0
 @RadBartTaylor: I've ridden it all. Cush XC is just expensive rim protection... no support. Cushcore pro is awesome but very heavy.

The best set-up is a light set of rims, EXO+ casing and Tannus tubeless armour... Tannus is light as CushCore XC yet all the benefits of CushCore Pro (support, damping and rim protection). Also way, way easier to deal with and install. Last time I put them in, I only needed to break one bead and didn't dump my sealant.
  • 2 0
 @islandforlife: I have been hesitant to try it because the Tannus non tubeless is so bad, but so many people like the new tubeless I think I’ll give it a shot.
  • 2 0
 @RadBartTaylor: as island said, the xc doesn’t really offer any support. It is just a rim protector. I run the xc with exo on my short travel bike and the pros with exo+ on my bigger bike.
  • 2 0
 @islandforlife: Same! I've tried more inserts than I care to mention and I landed on this exact setup--carbon rims, EXO+, and Tannus Tubeless. Only downside is the lack of run-flat capability. Never tried it with the Tannus but it doesn't seem like it would go well.
  • 2 0
 @Jabber127: you’re right it doesn’t go well. I had a sidewall tear while running Tannus tubeless and trying to ride that out was a sh$& show.
  • 1 0
 @islandforlife: I disagree that they don't offer support, I run the XC's on my 'downcountry' bike and it's a hell of a lot better than without, can run lower pressure much more confidently with than without them. Obviously nowhere near the pro's, but it's a step in the right directly IME.
  • 1 0
 @islandforlife: How much PSI are Tannus Tubeless riders finding you can drop (from no insert) and maintain good feel?
  • 2 0
 @Dr-Courvoisier: depends on a lot of factors including terrain... but 2 to 5 psi
  • 2 0
 @thechunderdownunder: Tannus tubeless armour is nothing like the tube version. It's everything @islandforlife says it is. He is also right on the money recommending EXO+ with it. I run this and you definitely feel the benefits of the Tannus inserts
  • 6 0
 Get a new Tannus tubeless insert and leave the tube at home. It is I think among the lightest, and it freaking works. It also helps prevent burping as it pushes the bead outwards. It also makes airing up a tubeless tire easy without a compressor....

I say "leave the tire at home" when a mile up my ride this morning my presta valve decided to retire early, and I had to walk/hike back to the car....
  • 2 0
 I’ve had a tannus front and cushcore back with no families on either for a bit. May eventually go tannus in the rear too to save weight
  • 1 0
 Tubolitos weight hardly anything. I haven't actually had to use it, but previous walk of shames has me hesitant to fully ditch a spare tube.
  • 6 0
 I've been using the tannus tubeless insert for about a year and am very impressed with it can run lower pressure for more traction and still has better sidewall support it weighs less than most inserts and it's supposed to be easier to install then cushcore I didn't find it that easy to install but never used cushcore
  • 6 0
 If you're setting up your longer travel suspension for the type of terrain/speed/aggression the fork/frame is designed for, it will effectively ride like a shorter travel bike on mellower terrain?

At least that's what I've found. My suspension is set up to use ~90-95% of travel on the more steep/technical/fast trails, and thus only uses ~75% of travel for the milder trail systems. Works well and no set up change required.
  • 1 0
 Less aggro terrain more stiffer less sag because why not
  • 1 0
 i often ride more tokens in bikeparks for a plusher feel but yes with a more linear setup running my 180 fork on home trails works good, i come home with 30-40mm not used
  • 1 0
 Regarding this question, no matter what bike you buy, no matter what modifications you make, there will always be advantages and compromises. There is no perfect bike. Get a bike and set it up “perfect” for you. Then ride the hell out of it.

Personally, the bikes mentioned above, Privateer 140 and 160, have so many similarities in geo, I’d just go with the longer travel and be done with it.
  • 5 0
 Cushcore XC has a lot of the benefits of the pro insert without the weight. The lower tire pressure dramatically increases traction and the sidewall support gives you more cornering confidence. Just wish they were easier to install.
  • 2 1
 No... no, no, no. Cushcore xc has only one benefit, rim protection. Nothing else. Used it for a few months after using cushcore pro. Sold the xc because it was useless for how much it cost.
  • 3 0
 Tannus tubeless Armour is the real champ, light as cushcore xc but actually has all the benefits of cushcore pro, plus way, way easier install... and cheaper.
  • 1 0
 @islandforlife: have you tried the Tannus Armor ( the kind that runs a tube)? I run CC, but am sick of sidewall slashes and would guess the Tannus Armor with the tube would be bomb proof..
  • 1 0
 I have xc’s in one bike and pros in the other. It is a pretty big difference in support. The xc is also really easy to install in comparison.
  • 2 0
 @islandforlife: Since you have experience with both, how does CC pro and Tannus compared in the ability to limp home with a deflated tire?
  • 1 0
 @CDT77: Haven't used the Tannus with the tube... only heard bad things.
  • 1 0
 @CaMKii: That's probably the one benefit where CushCore Pro trumps Tannus... you don't have the same limp-ability. Where I ride, sidewall slashes from rocks are super rare... so I just need to carry jabbers/bacon/CO2/pump and I'm good.
  • 1 0
 @islandforlife: Care to elaborate? Genuinely curious... because ironically.. I want a superior solution to CC as am getting sidewall slashes (often).. and we live pretty close to each other I bet!
  • 2 0
 @CDT77: Maybe it's more down to my rising style? I ride and race (well, no racing now), up and down the island but spend most of my time around Victoria (Hartland and Skirt), but I find most of the island (while chunky and rocky, especially in Victoria where I ride the most), it's not razor sharp rocks like some areas have to deal with. So, if you're getting a lot of sidewall slashes, the only real solution is DD or DH casing tires. There's still some great benefits to running an insert with heavy casing tires, but then it's a lot of weight. I don't tend to care to much about weight and just ride what works for me... but with an option like Tannus, if you're going to run an insert, it just makes so much sense... vs cushcore.
  • 1 0
 @islandforlife: 100% agree re DD or DH casing - ran that f/b in Whistler (on a different bike) and was great.. however, the best I can get (for my choice of rear tire which is a 3" HRII) is EXO (not even EXO+) ergo the Tannus armor with the tube seems a sensible choice - was curious re your comment 'only heard bad things' re tannus w the tubes were as its hard to get honest reviews on those things online..
  • 7 3
 Double Down casings may roll a little slower, but they also offer a lot more damping and support. And they don't get gutted like a fish every time you look at a line through some limestone or coarse/large crystal granite.

If you live someplace where you can dodge the weight penalty of beefier tires, by all means rock some EXO (or equivalent) casings. But if you end up in Vegas, on the Front Range, or anyplace else with a lot of pointy rocks, you'll end up with a sliced tire pretty quickly.

As for inserts, if you only ride buff jump trails I guess they make sense...........maybe?
  • 2 0
 Agreed and good points. I've recently switched to DD after flatting with EXO. Choice was to run EXO + insert or DD. Chose DD because same weight but less hassle changing tires. I prefer that damping you talk of. I feel that my tyres roll through the chunder better because a more supple tyre would get deeper into the rocks / skip across the tops less. I'm very happy. And I recently punctured my DD with a very sharp rock and so glad I didn't have to mess with an insert to patch the inside.
  • 4 0
 It would be great to have some baseline flex ratings for forks (fore-aft and torsional) as well as handlebars. There is so much anecdotal assessment going on with these products. There should be one organization that's responsible for all the tests.
  • 1 0
 Totally agree. At the price point of some forks there is actually little hard facts to make an informed decision on buying or not. Same with comparing two different models, but I understand that this is something manufacturers don´t want.
  • 7 0
 I think the answer to “cushcore or double down?” is “yes”
  • 2 0
 I like CushCore. Been riding a ground control and purgatory which have done a great job holding up! No issues since the CushCore install! Tires weight about 1100g a piece but just bought some maxxis that weigh less! Look forward to comparing the two!
  • 5 0
 If you are at pinkbike you can run a 140 bike as a 160. That's what they did with the Status at least.
  • 2 0
 I was running 10 and 12 pounds in my tire down a jump trail the other day no issues and no inserts. Spank oozy wheels with Conti der baron project 2.6 tires. Painful combo to mount up but I got 2 and half seasons on them and just ch aged the rear out as the front looks fine still.
  • 1 0
 I like Conti too but yeah they're tight. Any rim damage removing the rear tire, or did you just cut it off?
  • 2 0
 Local trails are lots of sandstone rocks and fast trails. 180# rider. Never had a problem with EXO casings on the trail bike when they were brand new with proper pressures, but I always wore down the sidewalls well before the tread and then they would tear once the threads were showing (rear tire usually).

After combining trail and DH bike into a single bike, I've always run a rear DH/DD casing, lighter front.

Currently running a rear DD aggressor and the side knobs are shredded with the sidewall threads showing after only 130 miles. Trails here eat wheels and tires. 28 psi rear, 25 front. Any less and denting rims. Never pinch flatted a DD or DH casing.
  • 2 0
 It would be an interesting bit of research to see if 'older riders' like myself who proportionally are more likely to have started riding on a hard tail with minimal /no suspension (Me, Specialized Rockhopper, 80mm RS Judy) now experience less punctures today. Did those formative years instil the subconscious choosing of smoother lines that are still at work today and result in fewer flats and broken equipment.

One for the puzzlers.
  • 1 0
 My140mm Pike Select + seems too harsh at beginning of travel. If I removed air pressure the sag is at 40% ... seems like I lose potential travel if there is too much sag. Compression is backed off completely and rebound somewhere in the middle.
  • 4 0
 You might just be used to more travel because normal fork sag is somewhere around 15-20% for manufacturer recommendations.
  • 7 0
 how old is the fork? might need a lower leg service
  • 9 0
 @njcbps It's counterintuitive, but at a certain point increasing sag starts to actually make your susp ride harsh. The reason is whilst riding you are now deeper into your overall travel, which is basically mid-stroke. This is NOT going to feel plush since you're now deep into the stroke. This is why you actually want to ride higher in the travel (with more air) because plushness is at the beginning of the stroke. This is why modern suspension uses larger negative chambers, it allows the bike to ride higher in the travel. Also, make sure you're not running too much low speed compression damping!
  • 1 0
 What year is it? Mine came with an older air spring or something. When I bumped it up to 150, I got the new air spring. It improved off the top performance noticeably. Sorry I don't have proper names for these air springs can't remember.
  • 1 0
 @tdel010: It's the Debonair air spring.
  • 2 0
 @mybaben: Good point, the travel gets more progressive.
  • 1 0
 @DanielP07: It's a 2020 Pike, without about 500 - 600KM on it. It's been the same since new.
  • 1 0
 @SeanDRC: The fork I owned prior to this was a 2002 Manitou ... 100mm? Rockshox recommends 30% (according to the fellow they interviewed on one of the Pinkbike podcasts).
  • 1 0
 @mybaben: Thanks, that's it-too many concussions. Here's some explanation of what I was talking about. It was an inexpensive improvement for me youtu.be/oaNV_PPvR5g
  • 3 0
 @mybaben: This could be exactly it. I'd try 20 - 25% sag @njcbps more sag does not mean more supple.
  • 2 1
 The select plus comes with the rc damper which is known for being stiff and harsh. It's because the rc damper has a very stiff shim stack to allow a lockout when you turn the compression dial all the way up. I'm unsure if they changed it for 2.1 charger but even the 2.0 charger had the harsh rc damper. I bought a rct3 damper and the harshness went away.
  • 1 1
 @njcbps: Speaking of progressive I felt that my suspension(esp. front) feel became increasingly progressive with the Cush Core. I did experience the damped feel but when I ran into things I felt it made my bike harsher, despite the lower pressures. Anyone else or am I out to lunch a bit???
  • 1 0
 I run a 100mm Pike RCT3 and it also felt a bit harsh for a while before I played with the settings. I was running 35% sag, 6 tokens, and compression mostly open and the fork felt nice and soft in the garage, but it dived, felt like it hit a wall deeper in the travel, and bottomed out a few times each ride. After taking out 2 tokens, increasing compression damping to somewhat firm, and increasing the pressure by 20psi, the fork feels much more supportive and composed, and the fork is ramping up much smoother. In short - I'd try taking out one or two volume spacers, pumping the fork up to about 24% sag when standing, and increasing compression damping a couple of clicks.
  • 1 0
 @Frankie2021: I'm sure it feels 10x better. People run their forks way too soft imo. I like 15-20% sag so it doesn't dive much. Granted that is on a coil fork. Air I suppose I would stick around 20 and go lighter on the lsc. It really surprises me how far in the travel people have their forks when they are on the front brake and have their weight forwards. Looks like it's at 80% of the travel a lot of the time. That is a sign of a fork that is much too soft I feel.
  • 1 0
 Pull a token or 2 out
  • 1 0
 Run inserts and less air in the front tire.
  • 1 0
 @Civicowner: good call. I used this fork for thirty hours with little intention of keeping it and without checking for tokens, and probably mistakenly concluded that it was too stiff for its weight. I detest tokens/spacers--waste of space. Mezzer et al ftw
  • 1 0
 @jasbushey: Do you mean tokens?
  • 2 0
 @njcbps: let us know if you find any tokens in there, and if removing them helps. According to manufacturer, their effect on topstroke is insignificant, but it's an easy place to start, and no cost if you've a lockring tool
  • 3 0
 @ceecee: "accordng to manufacturer" lol ...

Tokens are a plague honestly, they have their place but everyone just crams them in because they think only using 70% travel before it returns with the force of a cannon is better than using 90% travel. But hey, it made my fork bottomless

All while sitting 35% into the travel so a 170mm fork feels like 120mm
  • 2 0
 @njcbps: nope, tire. He said “beginning of stroke”. To me that’s not a token issue since tokens only affect the end 25%. If he had said mid stoke or harshness through chunk, maybe but in my experience beginning of stoke can be handled with less front tire pressure. I actually had the same sensation the start of this season mostly on slow speed or little bumps. I dropped a few psi in the air chamber but didn’t like the dive and mid stoke support, and settled on same air in fork and 1-2psi less in front. Just something to try.
  • 2 0
 @jasbushey: tokens definitely affect the start of the stroke. more tokens will make it sit lower with a similar effective overall spring rate

Here is an example using more tokens and lower overall pressures. Notice for the middle part of the stroke there is no difference in slope, yet one will get 40mm and the other will get 60mm sag

Original comment was complaining about having to run 40% sag to get the right spring rate (slope)
imgur.com/a/iZg1PrX

Also notice no change in ending force. In this case the fork with more tokens will bottom out more easily because it is not able to absorb as much energy, so in reality the more tokens setup will need to be pumped up more to prevent bottom outs, effectively increasing spring rate, while sitting lower than the no tokens
  • 2 0
 @Civicowner: so y-axis is Newtons of force and x is travel in mm? I'm comparing this to the graphs in the adsorption article...it's confusing because one can't actually use 70psi with three tokens w/o bottoming, and at 100psi the three token line (lowest line at 100mm?--I'm color blind) would have the highest N in the 32-42mm topstroke after sag? Would be nice if the coil weight were specified, despite the imperial unity.

It's no big stretch to think that tokens/spacers are a progressive crutch which reduces travel, and that the biggest manufacturers are in a competition to produce plastic waste
  • 1 0
 @ceecee: Yep, this is just an example/proof of concept of what happens if you set up diff setups to have equal bottoming force and overall spring rate. You should be looking for sag at a given N, because the rider weight is a constant.

And yep, lowest line is most tokens, highest is least.

The top air spring line (0 token) rises 400n in the space of 66mm. The line is relatively flat in the middle area, so it's roughly 6n/mm or 35lb-in. The lowest line looks a touch softer at the same area. The coil spring is 8n/mm or 45 lb-in. You can really see the air spring effect of firmer initial stroke and bottoming stroke, but soft midstroke. 0 tokens will have less sag than the coil, but offer less support due to the lower effective midstroke springrate

Tokens have their place, the only use for them IMO is to increase spring rate without increasing ride height, to maintain geometry. ie i'm at 15% sag and i want to run it firmer but that would further reduce my negative travel and impact my geo. So you can pop a token in.

Sorry for the wall of text i just found that graph interesting
  • 2 0
 @Civicowner: that's no wall--save those for the patent office, the taxman, and Marcel Proust. I too was engrossed by unattributed graph. Most appropriate use for tokens is--XC racing? Thanks for the help
  • 2 1
 @SebStott "If it's sharp rocks like flint or slate cutting a hole in the casing, an insert isn't going to help at all." I disagree.

What pops/cuts easier? A balloon blown up super firm to max inflation or a soft balloon blown up halfway that can conform around sharp pointy things? With cushcore you can drop 5-10 psi from the psi required to avoid wrecking rims & getting pinchflats. This then allows you tire to conform around the pointy sharp razor rocks on the trail and reduces the chances of sidewall slashes and punctures. Can it still happen, of course. But it happens alot less then a rock-hard sidewall
  • 7 0
 I see what you're saying, but in my experience it's more like 3psi that I'd drop from a tire with CushCore. Much more than that and you still get squirm in the turns plus a noticeable increase in rolling resistance.
  • 1 0
 @seb-stott: I'm 170 lbs and anything more than 18 psi in the rear feels too hard... I think I must be used to the squirm at this point. 16psi in the front w/CCxc.
  • 1 0
 I will argue that you can make bigger suspension travel feel the same as less travel...in the case mostly for people who like to run stiffer suspension and don't like the feel of softer suspension.. I personally switch from a 120mm bike to a 140 and notice a big difference in the riding hight of the bike! but I run my suspension with a 2-5% sag so of course ill notice the difference but only took a ride to get used to it! but I also personally think the average rider now a days (at least in Ontario) run their suspension way way to soft! I see people bottoming out over the smallest things and using way to much of their suspension not things that don't need a lot of travel
  • 1 0
 210lb rider who is not the smoothest and has has been on dual crowns since 1999.I'm still missing that stiffness coming from a Lyrik. Maybe the 38/Zeb/Mezzer would give me that direct response and control back? As far as flats... never needed an insert and have only had 3 flats on Michis(one nail, one tear and one rim failure) over the years. I have never run any other tires long enough to feel the suffering of others
  • 1 1
 cushcore & carbon rims & DD or DH tires is an absolute nightmare, especially to remove. good luck breaking that bead.

I’ve installed them by hand on aluminum rims. carbon is another story.

Like others, I haven’t had a single flat since switching to DD/DH casings. when I ran exo casings, random little things would slice my tires.


I ran cushcore for 3 years, and then took it out and barely noticed a difference.

The cushcore users end up running shitty xc tires with lousy grip/bad tread patterns or zero side wall support, and then claim the insert makes up for all the shortcomings of the tires. They also run crazy low pressures that increase the rolling resistance, as well as the insert creating a flatter tire profile and increasing the resistance.

One of my good friends was a long time cushcore rep. that claim cushcore makes about being about to finish your ride on a completely flat tire is BS. he destroyed his rim just riding a fireroad back to his car.

I run DD style tires, and 23-24 front/25/26 rear. maybe i’ll run 22 in the front if it’s super steep.

That low rebound effect cushcore claims is actually more of a result of the rubber compound in your tires. Some times are very bouncy; otherwise shave been engineered with rubber that rebounds much slower. it matters.
  • 1 0
 Heavy tires and inserts for me. I rip sidewalls for some reason and I ride carbon wheels (downhill) on my Enduro as I'm on Aluminum (for now) no inserts but heavier casings. When I go carbon wheels it will be both .
  • 4 1
 Did Richie Rude answer the heavy insert or heavy tire question.....
  • 2 0
 I'm a fan of inserts, but that occasional ride home wearing one like a bandolier sucks.
  • 6 0
 No need for that, at least with Cushcore. youtu.be/8ZwsZqyP6vw
  • 1 0
 You should check out the Barelli insert.
  • 3 0
 Long-travel vs Short-travel There is no replacement for displacement.
  • 1 0
 By now Pinkbike has so many slow-mo huck to flat films and they choos to post the one with the pole bike. @pinkbikeaudience still not over it?
  • 1 1
 I find it very hard to believe that inverted forks have less lateral stiffness, I can't see physically how that could be true.
  • 3 0
 Since the stanchions (the lowers, in this case) are able to move independently, the thru axle is the only thing preventing differential travel on the two stanchions. Any torsion of the dropouts or elastic stretching of the axle would manifest as lateral flex. At least, that's my understanding, as a dilettante.
  • 2 0
 @barp: That is an excellent point and probably exactly what the article is referring to. I would say "lateral stiffness" is a bad/incorrect term for that though, as that is not really a simple bending moment in the lateral direction on the stanchions like the compliance being described by fore/aft stiffness but rather a torsional moment on the axle/wheel in the lateral plane. I also wonder how much the difference in that "lateral stiffness" between fork types even matters on a mtb since a mtb wheel already lacks so much stiffness in the lateral direction that the compliance of the wheel is likely to give up much more lateral movement than either fork type.
  • 1 0
 @barp: The axle does nothing more than clamping force,like 16-20 nm. What really supports all the load it is the hub-forks interface.The hub has another axle(bearings run on it) who rest in the axle cups,then axle cups contact with the forks or dropouts. Peak Torque made an excellent video about that.
You need a good amount of torque to hold the wheel in place,in MTB bikes it is not a problem,but in some other bikes it is.
  • 2 1
 Don't worry about taking the cush core out, or putting a tube in with a stans dart. I don't even bring a tube anymore.
  • 2 0
 I run dh casing or double down with cushcore and barely ever get problems
  • 1 0
 Everyone rides Maxxis? Weird. Michelline wild enduros, 25 psi. Crushes in Moab and Big Sky.
  • 2 0
 What about medium travel bikes....
  • 2 0
 DH or DD and tire insert for the win!!!!
  • 2 4
 Wanna know what is even more effective to prevent flat tires then any kind of gimmick insert ??? f*cking line choose and rider skill.
If you don’t want to get flat tires, try improving your bike handling skills and line choice, instead of relying on a gimmick to prevent flat tires.
  • 3 5
 I run both heavy insert and heavy tire when riding in the mountains... I punctured DD tire through Procore having 25Psi in the main chamber... weigh 80kg with full equipment.
  • 2 0
 My dude
  • 3 0
 Not an issue if you do your RDLs
  • 3 1
 Learn how to ride mate.
  • 1 1
 @diegosk: I blame wide rim + semi slicks in the rear. But I can’t give up semi slicks... can’t quit’ya!
  • 1 0
 (Ask pinkbike)
Make a mobile app
  • 1 0
 The front wheel on that Raaw seems to be dished incorrectly...
  • 1 0
 140 is literally the exact same as 160. It's a trail bike.
  • 1 1
 ...fork stiffness and inserts....hmmmmm
  • 1 1
 Stiffer in fore-aft, loobed better = better in and out action?
  • 1 0
 crushcore good
  • 1 0
 Inserts and heavy tires
  • 1 0
 Loving these answers
Below threshold threads are hidden

Post a Comment



You must login to Pinkbike.
Don't have an account? Sign up

Join Pinkbike  Login
Copyright © 2000 - 2021. Pinkbike.com. All rights reserved.
dv42 0.020748
Mobile Version of Website