How Do the Pros Set Up Their Bikes for Extra-Steep Tracks? - Val di Sole DH World Cup 2017

Aug 25, 2017
by Mike Kazimer  
The Val di Sole World Cup downhill track doesn't take any prisoners - it's steep and rough, with very few spots for riders to relax their grip on the brakes. For that reason, bike setup is critical. Every rider has their own theories and preferences, but the overall goal is to find a balanced setup, one that allows them to avoid getting pulled into the bomb holes that litter the course, while also providing enough grip for the loose, slippery corners.

Pinkbike's Ross Bell caught up with one rider and five mechanics and asked them, "What changes did you make for this weekend's race?"

Brendan Fairclough
Brendan Fairclough

Brendan Fairclough's Scott Gambler
bigquotesWe've just taken a spacer out of the fork – I wasn't really getting full travel yesterday, which is kind of weird on this rough, bumpy as hell, nightmare of a track. So we just made a few adjustments to try and get the full 200 mil. I've puzzled this track for a few years now and I'm desperately trying to get my head around it. I've had a weird year, and I feel like my speed's been there, but I just haven't really been rewarded with the final run. It's been a funny one – I'm quite excited to get the year out of the way and start fresh to come in firing next year. But that's not a good way to think about it when we've still got two race runs left...

We've got a new DMR Deathgrip compound, super soft. Me and Ollie are calling it the “Sunday Best.” It's a nice new soft compound, we've got it in the flangeless option as well. We've got a 2.5” Schwalbe Magic Mary up front for the extra cushion for the pushin'.

As far as shock goes, we've still the same, with the Float X2 air on their, just to keep the back end up, to keep it from sinking into those holes. Apart from that we're pretty standard – tire pressure's the same, flat pedals still on there.
Brendan Fairclough

Damien Bideau Commencal - Ruffin Brothers
Damien Bideau Commencal - Ruffin Brothers

The Ruffin Brothers' Commencal Supreme DH
bigquotesWe try to raise up the front end to suit the steepness of the track, and we tried as well to put a softer spring on the rear, but we went back to the stiffer one. We just put a different idler pulley on the bike – we went one tooth up to remove kickback.

We put one more token in the fork to keep the support in the steep, and that's it. We tried to put more spacers under the stem, but we went back as well – it was maybe too much.
Damien Bideau

Kevin Joly Miranda Miller
Kevin Joly Miranda Miller

Miranda Miller's Specialized Demo
bigquotesSince yesterday morning the track changed a lot. At the beginning it was deep dust and really slippery, and now the lines are pretty much done. We already had a good setup to start, but here we need to be really careful about the balance of the bike because it's really steep. I think a harder fork and a little bit softer shock makes the balance better for the rider, and after we need to find the balance between a stiff enough fork but soft enough to get the grip.

The change we did last night worked good for Miranda this morning, and we're going to keep continuing that way. It's definitely a hard track to set up the bike for, a hard track to go fast but still save some energy to go all the way down with a good pace. It's easy to get tired on this track – it's all about balance, and having a good body position on the bike.

We changed the height of the front end, changed the spring to have a softer back, and are working on the rebound to make the fork return to its normal position super quick to keep the good balance of the bike.

We need to have a good balance on the steep section, but we still need to think about the flat sections. It's one of the most exciting tracks to work on this year.
Kevin Joly

Unior Tools Team
Unior Tools Team

Taylor Vernon's Trek Session
bigquotesWe've changed quite a few tires, but mostly rims, to get everything sorted from previous races. Shock maintenance, checking up everything to be race race ready – that's pretty much it.

Most riders are riding Magic Marys, but cut Dirty Dans are also an option – they're going to decide last minute, honestly. This is one of the the races we change the least – maybe because it's the end of the season everybody is ok with all their setups. No major changes to be honest. 
Chris Cabos, Unior Tools Team Mechanic

P.A Loris Vergier
P.A Loris Vergier

Loris Vergier's 27.5" Santa Cruz V10

bigquotesJust after Mont Sainte Anne he (Loris) went back home, and the only bike he had back home was his 27.5. He went for a ride somewhere in San Romo, in Italy, and he really loved it. Val di Sole is really tight, and steep and rocky, so he was thinking about going back to his 650b. I still brought his 29er, and his 650b, I made it like brand new again – it was all f*cked from the last rides that he'd done.

The first run on training he loved it, so he said he said, 'All right, that's it.' You know when you have something in mind, like you want to try something you have to, otherwise you're just not happy, so he tried it and he loves it. So yeah, we'll see how it goes.

We put the Buzzworks on to make it a little longer, so the reach is 8mm longer. This is a size large, so this puts it between a large and an extra large – the 27.5 extra-large was a little too big.
Pierre-Alexandre Roche

Jack Moir Intense
Jack Moir Intense

Jack Moir's Intense 29er
bigquotesThe frame has the same reach numbers and everything as the alloy prototype he rode at MSA, so as far as fit and everything like that it's identical. For the suspension, because it's carbon and is actually quite a bit stiffer than the alloy is, we've tried to make some changes in regards to that to try and compensate for the stiffness of the frame. We've been playing with different tunes and shim stacks, but I think we've found something we're happy with.

Tire pressures are the same, but kind of like at Fort William I've detuned the wheels, reduced the spoke tension a little there just to help the bike track a little bit better, because it's so loose and rocky all at the same time. You kind of need that, especially when the frame is so stiff.

For the fork, we went down 2 psi from MSA, and we did one more click of low-speed compression, but other than that the fork is still the same. He's running air, he has been for the last three World Cups I believe. He was running coil most of the season, but the last few we switched just to give us a little bit more of an adjustment range. I think he's pretty happy with what he's got right now.
Chappy Fiene


  • + 183
 Minaar now testing a fully adjustable floating head angle... Not sure it's gonna catch on
  • - 104
flag Dickiescbb (Aug 25, 2017 at 13:15) (Below Threshold)
 clearly, u only looked at the picture and not read the comments....
  • + 69
 @Dickiescbb: clearly you've not been looking at other news...
  • + 37
 @mickeywillis: yea, what about the solar eclipse
  • + 12
 It'll take just a bit of core strength...
  • + 26
 Trump looked directly at Greg Minnaar's bike during the eclipse without sunglasses. What a fucking idiot.
  • + 10
 why do these guys get so much attention to bikes I never set up my 2004 Kona super stinky and I go faster
  • + 0
 beat me to it
  • + 62
 so they want to make Jack's new carbon frame feel more like the alloy one... remind me why we need carbon again?
  • + 95
 The weight, I heard the climbs there are brutal.
  • + 4
 The stiffness, or is it the compliance? IDK
  • + 2
 @EagleOfFreedom: that's what the lead shot we saw at fort william is for
  • + 9
 For the dentist
  • + 61
 you know you made it when 2 psi makes a difference.
  • + 13
 Placebo perhaps
  • + 73
 I don't even notice a slow puncture until the rim starts to hit every rocks
  • + 27
 5 psi make quite a difference for me, 2 for them seems reasonable
  • + 17
 And one click of low speed compression
  • + 1
 There are times when I can feel that my chain needs lube, and then feel the difference after I clean/lube, I can see feeling 2PSI no problem when you ride this much.
  • + 22
 Ok that Commencal spacer setup is too much, that needs to be one spacer, not five. And the bolts need to be shoulder bolts of a decent grade. A higher rise bar or drop crown would be a better solution. Seems sketchy, even just to try for a run.
  • + 36
 Ah, judging by your giving recommendations, I assume you have ridden the Val di Sole World Cup track.
  • + 33
 @Neechy: I don't think he is questioning the setup as such, just the way it has been achieved - e.g. With higher rise bars rather than lots of spacers and the use of higher tensile bolts as they get longer.

Read it back, it's pretty obvious he isn't criticising his bar height etc just suggesting other ways of achieving things.
  • + 26
 @Neechy: I think he was talking about the stress those bolts have to whitstand with all those spacers
  • + 1
  • + 17
 @Neechy: My comment was related to structural integrity only. I indeed reserve comment on whether a bar of that height is actually needed because, as you point out, I have not ridden that track.
  • + 1
 @dugglesthemuddled: Check out pictures of Minnaar's and Peaty's setups from a few years back, when they were still on 26" and boxxers. They were regularly using drop crowns plus stacks of spacers to get the bar height needed for those tall guys. Also I don't think the bolts are a big concern, since they are a disposable item at the WC level. They get replaced so often that fatigue isn't an issue, plus they can use Ti or fancy alloys to get the strength they need.

As far as riser bars go, they are very rare in WC DH, even for the tall guys. I have never heard an explanation for this, but my guess is that the rise creates potential for greater torque at the bar-stem interface. The last thing you want on a course like VDS is your bar rotating at the stem.
  • + 7
 only one way to find out, fucking send er.
  • + 4
 @kabanosipyvo: Renthal racers constantly use 30 and 38mm rise bars.
  • + 3
 Maybe looks a litte ugly, but it´s stable enough. This makes sense because it´s easy to test more different stack heights with that spacers while keeping the rest of the cockpit as used. To test different bars and stems between practice runs is more complicated.
  • + 4
 Maybe instead of critiquing the best mechanics in the world as doing something unsafe, why not say something like "wow, I didn't realize you could use that many spacers and be totally fine?"
  • + 12
 Just so you know, the longer the screw, the better elasticity it got. Longer screws are tougher than short ones.
Critical assemblies withstand better when the length of the stack up is minimum 3 times the screw diameter.
Yes I work as a mechanical engineer Wink
  • + 2
 @gonecoastal: I guess I wasn't clear in my last comment; I meant high-rise bars like 50mm+ as hardly anyone runs flat bars either.

But it's just my armchair opinion, after all.
  • + 25
 Can you do a bike check of Minaar? I'd love to see how his bike adapted to the track!
  • + 15
 He seems to prefer his bike wrapped around a pole and broken in half as his ideal bike setup
  • + 9
 He is running the new Santa Cruz invisi-link frame. Constant on the fly reach adjustments from the looks of the video I saw...
  • + 6
 Variable Wheelbase Technology
  • + 12
 it sounds like the intense is a little too stiff, witch i think alot of carbon bikes are, especially dh bikes. The stiffer is better idea is one of the great oversimplifications of the bike industry.
  • + 3
 I can see the next big step in carbon frames being controlled amounts of flex, similar to hockey sticks.
  • + 2
 @derrie: road bikes have a similar approach
  • + 5
 As a big fat weekend warrior i welcome the excessive stiffness real athletes suffer with.
  • + 11
 29 front and 27.5 rear would be perfect for this track! Let em have it UCI!
  • + 4
 Been saying this forever Smile
  • + 5
 Holy b***s, I've been looking for verification on changing the spoke tension for that very reason for awhile. When my wheels are up to spec tension it feels like I'm a pinball in rock gardens. much bike porn. That and Vernon going with Hope tech 4 DH rims, f***inoath mate
  • - 1
 Yeah, it seems some riders are looking for less lateral stiffness in their wheels for better tracking. Reducing spoke tension is one way. Downsides are that under very high impact loads spokes may become unloaded which is bad for fatigue life. The alternative would be to have hubs with narrower flange spacing so that you can still run high spoke tension. It may take another hub standard in a couple of years.
  • - 3
 Lowering spoke tension does not affect the stiffness of the wheel.
  • + 2
 @vinay: AFAIK spoke tension doesn't affect lateral stiffness. If I remember correctly it was mention in the article about Giant team data acquisition tests
  • + 9
 @ORTOGONAL555: The summary of that thread was that, because the Young's modulus (i.e. the stiffness) of a material is basically constant, lowering or raising spoke tension literally cannot make a difference to wheel stiffness. There are caveats to that though: if you have such low spoke tension that impacts to the wheel can completely de-tension any of the spokes, those spokes aren't going to be offering any wheel support during those impacts, so the spokes which still remain tensioned are now going to each be carrying more load, so stretching more, allowing the wheel to flex more than it would, if all the spokes were still supporting it.

That also means that, if you try to massively tighten all your spokes, your wheel won't get any stiffer either. You'll probably just pull a nipple through the rim, or strip you spoke threads, etc
  • + 3
 My entire experience with this is entirely isolated: I changed the tension on my rear wheel up to spec, after letting a friend who happens to be an experienced downhill race mechanic loosen the tension on both wheels.

The next ride I went on after going back up to spec it felt as if the wheel was transmitting more feedback/force to the suspension which resulted in a very harsh feel, where I could feel every pebble in the trail through the rear end and pedals especially. That and the rear brake makes a little noise now.

So the way it was set up by my friend sounds "detuned" according to the article. It doesn't effect stiffness of the overall rim profile, bit it does effect how much force is absorbed or transmitted before the suspension comes into play, similar to how tire pressure and unsprung weight can effect suspension performance and bike feel.
  • + 4
 He's not wrong though. One of the first things you learn in materials engineering is that a material's stiffness cannot be altered, since it relies on the strength of the bonds between its constituent atoms. A material's stiffness essentially tells you how much it will extend, per unit of load applied. Think of it like a coil spring - a 10N/m spring will always extend by 0.1m, if you increase the force on it by 1N.

If you put it under 8N of tension, it'll extend by 0.8m. If you add another 1N, it'll extend by 0.1m to 0.9m. If you only had 4N of force applied, adding 1N of force would still produce 0.1m of extension. That's why, for a given impact force to a wheel, it will always deflect the same amount, regardless of spoke tension - the deflection depends on the stiffness, which is always the same, not the tension.

Young's Modulus is the concept which is important here, for anyone interested.
  • + 0
 @Smevan: but reducing tension allows spikes to move more, giving the wheel more compliance. Imagine if the spokes were an inch too long (ignoring the problems that would cause with rim tape and such) you would be able to move the rim by hand and it would flex substantially, no?
  • + 2
 @Smevan: nevermind, I just read up on it and yeah, you're absolutely right, and the example I gave would be the exception, when spokes are loose enough that they're slack. Pretty interesting
  • + 2
 @kleinblake: The comment thread that @ORTOGONAL555 is referring to was the first time I'd really thought about the effects of tweaking spoke tension (or the lack of effect) and it was an interesting read. Always nice to see some of the physics from school actually be useful, sometimes
  • + 3
 @Smevan: I'm looking forward to using the physics I learned on pinkbike in school!
  • + 1
 It's curious that the Pros are "De-tuning" their wheels by reducing spoke tension when it seems to be common knowledge that this doesn't have a noticeable effect on wheel system stiffness. One commonly referenced (but dated) test to prove this idea can be found here:
Personally I find data much more convincing than anecdote even if these anecdotes are from world class racers and techs... even those individuals may fall victim to pseudo-science. It seems a lot of other commenters are right on the mark with questioning this logic.

Edit: not to mention this idea can be dangerous if it is taken to the extreme; leading to complete wheel failure if the reduction of spoke tension exceeds a certain threshold...
  • + 1
 @BadMotor: I agree with you. Another one that gets people is clipless vs flats for pedaling efficiency, where data doesn't at all back up anecdotal claims, and yet there are still pros that swear by pulling up when pedaling. My favorite is Commencal and their anti-vibration stickers that use "quantum entanglement." I mean really? Just get a wizard to cast an anti-vibration spell on your components, that's what I did.

Anyways, a little clarification from my experience: I do feel more harshness in rock gardens with spoke tension up to spec with my rims. The front wheel is doing great with a "detuned" set up and I haven't broken any spokes, the decrease in tension in the front wheel is just below the spec'd minimum tension, on just a few spokes, the average tension of the front wheel is right in spec. The rear wheel is in spec, no spokes over tensioned.

Based on the difference in ride feel in the rear end, changing only the spoke tension, and riding the same test trail back to back on each set up, my ability to track a line didn't change based on wheel stiffness, it did change based on how much feedback was getting sent through the rear wheel into the suspension and frame. Low tension, within spec, is comfortable and smooth, if I want to I can set the bike up to ride on a mattress through rock gardens. High tension, still in spec, makes it feel like my rear shock turned into a jackhammer, so it's not that I can't hold a straight line and track like I could with lower tension, it is just awful feeling.

I think this happens a lot, where what we think we're feeling and what's actually happening have a disconnect. It would be easy to misconstrue the change in ride quality as due to wheel stiffness. In fact before I read through the articles posted here I would have felt that was a reasonable explanation.

All I know for certain is it feels different, for whatever reason. I don't have the nicest wheels either. I have fixed a fair few dents in my rims and I don't think my experiment counts as vailid without using several sets of identical and new wheels to test on, and of course more than one test monkey.
  • + 1
 @ORTOGONAL555: Could you refer to that article? I'm interested.

As always, discussions like these are difficult without the ability to communicate graphic material. I'll give it a shot.

First of all, I don't think stiffness in radial direction changes with spoke tension as long as they stay in their elastic range. Agreed that is not what this discussion was about but then again most of the arguments brought forward do indeed count for the stiffness in radial direction. Under a rim load from below the top spokes are stretched by the same rate as the spokes below are allowed to shorten (that is, reduce their preload).

What is different with a lateral deformation is that left and right spokes strain at a different rate, even if they're symmetrically laced (EVO6 or similar). That's due to the spoke angle. If the tire is pushed to the right, the spokes left will strain more than the ones at the right will "shorten" (by which I mean reduce their elastic strain due to the unloading). For most metals, the elastic region is considered linear hence the tensile force is considered linear with the strain. So if the change in strain is not equal between these sides, so isn't the change in tensile force. There is an absolute difference between these forces. And if the preload is higher, the absolute difference is proportionally higher too.

Now this is already a very much simplified model. First of all the rim won't shift parallel to the wheel axis. Instead it will shift only slightly but most of all it will tilt. The same applies as mentioned above (that is, above the axle the same will happen but in the opposite direction). Then it also isn't easy to look at spokes in a 2D plane. Unless it is a Crankbrothers wheel, the spokes don't pull in exactly the same spot. And unless the wheel has been laced radially (which can't be done with mountainbike disc brake wheels), the spokes also have a huge radial component.

Now I wouldn't necessarily say that this is the cause for the added comfort and tracking people experience. It is one explanation, the other is that the lower spoke tension has a lower eigenfrequency hence transmits lower frequency vibrations to the rider. But if people aren't even sure whether it is actually experienced or just perceived, it calls for a blind test.
  • + 2
 @vinay: You're right to point out that the trigonometry of the wheel is important here. Once you get really specific though, the number of factors influencing wheel compliance and whether you even notice changes in it, becomes pretty large:

- initial wheel dish, plus the rate and direction of change of the drive and non-drive spoke bracing angles
- the fact the spoke tension is lower at the bottom of the wheel than at the top
- the roll, pitch, yaw and 3D translation of the rim about the hub
- the deformation on the rim itself (both in and out-of-plane) and therefore the rim construction/design
- the fact that cross-laced patterns leading to spokes being statically bent in one plane, but potentially also
bent unevenly in a second plane, as friction at the crossings means the majority of flex, under acceleration,
happens in the spoke sections between the rim and crossings
- the deformation and characteristics of the tyre (casing construction, pressure, tread, rubber compound, etc)
and whether that's more, less, or equally significant as wheel compliance
- frame flex and whether that's more, less, or equally significant as wheel compliance

There are probably more, but just based on this, I suppose the admission has to be that the "stiffness is constant, so wheel deflection doesn't depend on initial tension" argument is, at best, only a half-truth and that all this massively depends on the rest of the kit you're running.
  • + 4
 Now I'm kerrfuzzled-

Every review bangs on about the bike stiffness, wheels stiffness etc and now we need to de tune our wheels and go to ally as it's too stiff? Zut alors delboy
  • + 7
 All I want to know if the tree is ok?
  • + 3
 Chappy Fiene said he reduced spoke tension to make the bike track better. Some tech wizard from the internet better go beat him over the head with Jobst's book.
  • + 4
 Carbon rims...too stiff?
  • + 2
 hahhaahha!!! so accurate

to be fair Jobst was a roadie, and before carboners...(albeit one who rode blown out dirt roads on tubulars)
  • + 1
 So, what difference does a different size idler pulley make? It never occurred to me that it would matter at all, I just assumed you'd use the smallest one that would roll smoothly.
  • + 5
 Different sizes create different chain angles. The larger the pulley, the steeper the chain angle. And vice-versa. The differing angles will react differently to the suspension path just as other suspension designs do with different size chainrings.
  • - 1
 I understood pedal kickback as being a result of chain growth, in which case, I don't see that a bigger or smaller idler should make any difference - the suspension geometry would be the same, so the chain growth for a given amount of compression should stay the same. The idler is concentric with the main pivot, increasing its diameter should increase the tendency of pedalling to induce suspension squat, but wouldn't do much else.
  • + 5
 @Smevan: it does effect chain growth and more importantly antisquat. Moving the chain angle closer to the pivot point reduces antisquat. It's all about where the line from the the hub axle to the pivot point intersects the line from the chaining to the cassette cog that the chain is on.
  • + 0
 @panaphonic: The idler on the Commencal is concentric with the main pivot, so the chain is always running above the main pivot and you can't get anti-squat if the chain is pulling above the main pivot, no matter what size idler you're running. The direction of the chain tension is always going above the main pivot, so the rotational moment its producing is always acting to pull the swingarm into compression - the tension would have to pull under the main pivot, if it was going to produce anti-squat under pedalling.
  • + 3
 @Smevan: @Smevan: Th idler on the commencal is not concentric with the main pivot. Wink
  • + 1
 @faul: Looking at it from the side on, it's always looked like it is. You're right, it's actually located a little bit further down the seatstay. Regardless, the path of the chain is not below the level of the main pivot, so the original point stands - there's no anti-squat characteristic to the suspension, under pedalling.
  • + 3
 Is Val di Sole steeper than Andorra? There wasn't this much hype about the steepness then
  • + 1
 Yeah I don't get why loris said he would ride 27.5 because it's too steep but in Andorra he was riding 29 with no problem. I have never been to VDS or Vallnord , so I can only judge from Pinkbike picture but Andorra looked steeper. Anyone have been to both ?
  • + 5
 @zede: Andorra is probably steeper, but as mentioned in the article he made the switch after trying the smaller wheels back at home
  • + 9
 It's a mental game. He feels better on the 27.5 so that's what he is running. You can throw all the data you want at a rider, some of them will go on data, but most are going to ride on feelings.
  • + 1
 @ORTOGONAL555: yeah but I'm more referring to the vital interview where he specifically mentioned the issue of steepness+29. That being said he knows his stuff better than me so why am I even discussing it
  • + 1
 @zede: I think it's more cause it seems like Val di sol is tighter than valnord, I could be mistaken as I haven't been to either but I think he and a few others mentions how tight it is
  • + 0
 @treymotleyDH: it made me think he was saying 29 was better because that's what they told him to say. You know, keep the hype train rolling. Now he's had a few fast qualis but failed to put it together in a race run, he's doing a Hart.

I said everyone will be on 29 next year but now I'm changing my mind. f*ck it I have no idea.

Money McGregor anyone? No idea!
  • + 2
 @jaame: hahah two competitions I have no idea what the outcome will be! But as far as the 29 thing, I think the lack of testing from brands was the downfall for some for this season. Greg pretty much told loris to ride the 29 because he was faster on it and he could've been but it wasn't like they had a huge offseason to practice on them. It was near the end of the season that all that started to come together. I recently got a 29 and love it but it's not for everyone, and every bike has its advantages. Give it two more seasons and I think 29 will be the more common choice.
  • + 3
 @zede: pure speculation on my part, but a steep track may remove the advantage of 29. 27.5 may be easier to control your speed and the steeper the rock garden the less need for rollover as you will be going over those rocks lighter than you would on less of a grade. Again, this is pure speculation. I'm sure very few PB readers have ridden a 29 dh bike and can give much definitive insight.
  • + 1
 That Commencal looks like it rocking the old ATK 406 chain torque eliminator technology.
  • + 2
 Green foam rims give you green light split times!
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