Stiff like Wood Wheels
EDITORIAL

Stiffer Isn't The Solution

Words AJ Barlas
Photos Google Images
Date Feb 23, 2018

Working with Stiffness Over the Years

It’s 1999, Nicholas Vouilloz has wrapped up the Downhill World Cup Series overall and World Championship, leaving competitors scratching their heads as they try and demystify how the Frenchman can continue handing them a can of whoop-ass race to race. It’s still the early days of downhill mountain biking and every season brings quite a number of advances in bike technology but Nico still seems to be on another level. He has so much control regardless of the terrain, seldom fighting with the bike as it speeds across the terrain. 



It’s very likely that anyone who followed DH racing during this era will have heard of how meticulous Vouilloz was about bike setup, especially in regards to his suspension, but one attribute that some may not be aware of and indeed I only recently discovered, was his work on the bike's stiffness. Actually, it would be better to think of it as flex, because he was really working on how the bike flexed so that it would hold a line well, as opposed to making it as stiff as possible. Sure, Nico was a lightweight rider so a little extra give would have been helpful, however, he was the fastest man in the world, winning multiple World Cup Series overalls and World Titles during his time before deciding to step away from racing bikes. Being that fast and riding at such a high level, regardless of weight, is going to place a lot of demand on a frame. 

Come forward a few years to 2004 and Jared Graves has signed with Yeti. Coming to the brand and riding a DH bike developed with Nathan “Stomper” Rennie saw Graves swinging a leg over something that had been stiffened up considerably because of Rennie’s solid 6’3” stature and his desire to smash his bike into corners and obstacles on the trail. For Graves, the bike was stiffer than he’d prefer, not only because he’s not as big as Rennie but also because he rides differently to him. This resulted in him finding ways to ease it off a little, allowing the bike to flex more to his liking. 

In 2010 the Syndicate were officially on Enve wheels and over the years since it hasn’t been uncommon to hear tales of racers like Greg Minnaar, a rather large human himself standing at 6’3”, having the spoke tension backed off in order to get a little more give from the hoops. It’s something that Vouilloz had also done but here we were, some ten plus years later, still using the technique to help a rider get the feel and compliance that they are chasing from their wheels. 

 

16-ENVE.jpg?w=760

Enve's original M-Series wheels were very stiff, but were still a popular wheel out on the trails. 


We've Gone Too Far, Reign it Back In

When carbon began to ramp up in mountain biking around 2012, every brand was touting stiffer this and lighter that. As the years progressed more brands would release a new part made with the fantastic plastic boasting similar claims, which must mean it was a better part, right? Wrong. More recently we hit a point where a number of brands realized that the limit had been met and indeed exceeded, and instead began to “soften” things up. It surely won’t be that simple, though, with everyone enjoying flex properties of varying degrees from their bikes. Just like Rennie being bigger and more aggressive than Graves, the average Joe varies greatly in riding preference, terrain, experience, and size. 

Nevertheless, we’re at a point where more riders are coming to the realization that carbon isn't always all that it's cracked up to be on the trail. Include in that the added cost of the products made with the material and we see a number of riders continuing to stay with alloy, even going back to it. The move is most notably in relation to wheels but there are riders that won’t run carbon bars because they’re too stiff, and there are carbon frames that are too stiff for how some folks ride. 

Getting flex “right” is a tricky proposition, though, with so many varying degrees of attributes to be taken into consideration; throw in rider preferences and it becomes even more challenging. Rider size is perhaps the most tangible way to look at things but even then, some lighter riders would push their bike as hard as someone weighing 50% more than them. Then there’s the fact that a stiffer wheelset can work fantastically on a softer flexing frame, within reason of course. There’s a lot to be considered!


Stans Arch Wheels on Carbon Bike

The older Stans Arch wheels were often too soft for some but perhaps fitted to a stiff carbon hardtail they would have struck an excellent balance? 


So while stiffer definitely isn’t better, softer isn’t necessarily the way either – we don’t want to be riding wet noodles, that's for certain! This got me to thinking; what if brands began to work on grades of stiffness in their product lines, giving consumers the choice to select a product that they feel will work better for them based on how they ride and what they like the feel of? Just like suspension setups varying dependant on the rider, the flex of the product would allow us to better setup our bike for how and where we ride.

Like many things, arriving at this point is the result of going too far in one direction and despite there being different tastes and needs in flex, a number of products got too stiff in recent years and things need to level out a little. How far that goes is where I hope to see brands using some ingenuity and working on something like grades of flex for rider weight or style within each discipline, rather than simply by price or discipline (XC vs DH, for example). No one likes riding something that feels like a block of wood but being able to choose the amount of flex on a scale of wood (teeth rattling stiff) to wet noodle (flexy af) would be a great benefit to consumers everywhere, regardless of their size, preference, or experience. 



Comments

Vikb
+1 Cr4w
Vik Banerjee  - Feb. 23, 2018, 6:35 a.m.

Especially when I am road tripping and riding everyday for 14 days+ what stops me from riding is getting beat up especially in the upper body [ie. elbows and to a lesser degree hands].

For my new bike I am experimenting with:

  • aluminum frame

  • coil suspension

  • aluminum wheels

  • comes with carbon bar, but I'll consider swapping out for metal

  • softer grips

I'm curious to see how that all adds up for longer term body abuse and see if there is a noticeable difference. If there is I'll use this new bike for my road trips [often to the desert where rocky high speed smashing is normal] and keep my existing bike for local riding where I ride less back to back days plus trails are softer and slower. 

Reply

AJ_Barlas
0
AJ Barlas  - Feb. 23, 2018, 8:49 p.m.

That's an interesting point you bring up, Vik. Riding consistently and on consecutive days would definitely have more of an effect on the body from a harsher feeling ride.

Reply

tehllama42
0
Tehllama42  - Feb. 25, 2018, 6:04 p.m.

The additive abuse is pretty underrated as a performance factor.  That's why FS bikes are quicker over distance despite being mechanically less efficient - not having residual core muscle tension and needing to go to full exertion over medium chunder adds up to more gas in the tank, even if its being used less efficiently.  Even on my short average rides (~1.5hr), having my suspension set up softer and better damping on carbon stuff, I was setting KOMs at the end of the ride just because I was fresher than I've ever been - despite feeling like I was utterly out of shape on the climbs.

As a big guy, (I'm up near 235 sans gear anymore), XXL bikes are finally stiff enough (carbon everything) that I'm finally experiencing what everybody of normal size can get out of reasonable weight bikes.  I could do with stiffer, and make up a lot of that difference in suspension setup, even laterally.  I could also do with lighter, since I'm destroying 900g tires off and on with the strange mix of rocks and cactus we have here... so I'd argue they haven't gone too far in every capacity - they'd just gone 'too far' for the average rider, and are finally hitting the sweet spot.

Congrats to RockyMountain for having actually gone far enough in the first wave of XXL sized bikes so that their ostensibly 'XC-Trail' bikes (Thunderbolt, Instinct) can actually be kitted with Clyde friendly suspension (fork, shock) and decent enough wheels/tires that they can actually be good bikes despite having big riders.  I think that frame as set up ends up not being overly stiff (basically middle of the road once you compensate for my fat arse), and despite carbon wheels it is a plenty complaint setup, and I just love i overall.

Also, I do think that sometimes carbon bars can actually better on that front - add beefy ESI or Gum Rubber (Sensus) grips, and I've been impressed with how much less arm strain I'm having.  Ditto on moving to a TopazT3 shock - coil-like feel, and though it visually bobs slightly when pedaling (despite an oval chainring), I'm actually at the same energy level at the top of climbs, and able to charge much harder downhill.

Reply

cooperquinn
0
Cooper Quinn  - Feb. 27, 2018, 1:11 p.m.

Suspension losses (but confusingly, not BICYCLE suspension) are a very real thing. 

Its.... complicated, but kind of boils down to all the friction inside your vibrating tissues - especially higher speed/frequency vibrations. Like those that might be more likely to be transmitted to you, Dear Rider, if your bike is overly stiff through the wheels/frame/bars. 

So that fatigue you feel over several days? Its real. 

And I'm with Tehllama42 - ESI Grips FTW.

Reply

craw
+1 Vik Banerjee
Cr4w  - Feb. 23, 2018, 7 a.m.

As a taller/heavier/stronger rider I'm loving the stiffness. I think a lot of frames are engineered for someone more average so when you stretch out the numbers to XL bikes ends up a bit noodley just from the added ength and rider leverage. I'm sure some companies vary the carbon layup schedule for bigger sizes but I don't know which ones.

This current generation of bikes suit me just fine. Carbon wheels too, especially 29". But I could see how it might be too much.

Reply

Vikb
+1 Merwinn
Vik Banerjee  - Feb. 23, 2018, 7:10 a.m.

Good point. I'm 200lbs geared up to ride and my GF is probably 130lbs. We don't need the same level of burliness in our bikes and in fact overly stiff parts can work against lighter riders.

Reply

dtimms
+3 LWK Cr4w Scroggins
dtimms  - Feb. 23, 2018, 8:41 a.m.

It is a great idea having stiffness levels in frames but all I hear is that costs will go up do to stocking different flexes in all sizes. One thing that is already available is the ability to purchase bars, wheels etc... to get us closer to the feel we want.

Reply

LWK
0
LWK  - Feb. 23, 2018, 9:25 a.m.

this, exactly.   dont give the manufacturers any ideas!

will be interesting to see how your Knolly Warden carbon vs. aluminum test will play out in this regard

Reply

tehllama42
0
Tehllama42  - Feb. 25, 2018, 6:07 p.m.

I think they already should be - the intent of the bike (and rest of the build kits to some extent) should inform bike manufacturers which layup stiffness targets to shoot for.  End user adjustments (wheelset, suspension setup, tire pressures) can make up a lot of that difference too.

I think for entry level stuff, it's a really good thing that aluminum wheels without super-high spoke tension are a good thing (just pair them with decent rubber, please).  At the higher end, then trying to run carbon fibre everything starts to make lots of sense... maybe for the XL sizes on things, try and make up some frame stiffness if the components aren't going to change underneath (because to be honest, us clydes don't mind an extra half pound of bike weight if it means having uncompromised handling - particularly on price point complete bikes that will have wheelsets and forks which are great on median riders, but be at their limit with us on them).

Reply

cooperquinn
0
Cooper Quinn  - Feb. 27, 2018, 3:41 p.m.

To your point - think about bike weight as a percentage of body mass, not as a stand alone number. 

W/kg is more important than W.

Reply

Scroggins
+1 JVP
Scroggins  - Feb. 23, 2018, 8:53 a.m.

Very good points. Being a 200+ pound rider myself, I value carbon "stiff", bits I get to ride these days. In my opinion there are loads of companies that are offering bikes and components in a variety of stiffnesses.

Take Race Face for example. They offer a crank, handlebar, stem to pretty much suit anyones preference on compliance and stiffness, carbon or aluminum. And there are many different wheel manufacturers that offer aluminum rims that are even "weight weenie" approved, all while feeling less harsh then carbon. 

I think that all I'm trying to say is that although the bike industry might have gone to far, which it usually does. It ended up creating bikes/components that are the most reliable, trustworthy, and capable then they have ever been. Some might remember that although the bikes may have been more compliant in the early years, racers were going through frames like they were going through underwear.

Reply

JVP
0
JVP  - Feb. 23, 2018, 5:12 p.m.

This ^  If it's more reliable, I'll accept a bit of harshness.  MTBs are freakishly good and reliable these days, especially for the weight.

Reply

bart
+1 Cr4w
bart  - Feb. 23, 2018, 9:39 a.m.

road bikes have been doing size specific carbon lay ups for years - about time the MTB side of things figured out how to achieve the same.

Reply

Xorrox
+1 Scroggins
Brad_xyz  - Feb. 23, 2018, 9:44 a.m.

For mountain bikes, I'm definitely one of the "stiffer is better" proponents.  I'm an outlier at around 235 lbs riding weight with foot ball player legs, so for me frame and wheel stiffness (at least laterally) are a must if I want peddle mashing efficiency and stability in the rough.  I always have to tension my spokes to the max on both carbon and aluminum wheels or they come loose all the time no mater what spoke prep I use (short of loctite which I may try next time).

I prefer a very stiff full suspension bike and wheel and then to fine tune my vertical compliance with suspension adjustments, tire size, pressure and insert options (I'm a big fan of ProCore but wish they would release a version with a longer valve stem for higher profile carbon rims) and bar / grip choice. 

That said, the level of stiffness I crave would likely be harsh for a lot of other riders out there.

Reply

alexdi
0
Alex D  - Feb. 23, 2018, 10:01 a.m.

I question the desirability of frame flex with FS mountain bikes. These frames are rigid to provide a stable mount for suspension. Flex changes the suspension kinematics and introduces undamped rebound. The result is unpredictable handling. Ride quality suffers for lighter riders not because the frame is excessively stiff, but because for a given bike configuration, they reduce the ratio of sprung to unsprung mass.

There's an argument for engineering vertical frame flex into hardtails, but even here, the effect would be modest (perhaps even imperceptible depending on the configuration) relative to the tires. 

> there are riders that won’t run carbon bars because they’re too stiff

You can't make uniform judgments by material. Some carbon bars are very stiff. Others are not. The only way to tell which is to test them.

Reply

AJ_Barlas
0
AJ Barlas  - Feb. 23, 2018, 8:53 p.m.

Having ridden a couple of carbon DH bikes that had a front triangle that was too stiff compared with their alloy counterparts, I'd have to disagree. Definitely, there needs to be a stable mount for the suspension, totally agree, but it is possible and has happened, where it goes too far and the bike starts to deflect off obstacles where the alloy would provide a smoother and more accurate ride. But yes, it's more commonly felt with wheels rather than frames because as you point out, it needs to provide a great base for the suspension to function properly.

Reply

Kenny
0
Kenny  - Feb. 23, 2018, 1:37 p.m.

I think frames should be as stiff as possible to minimize the number of variables. Adjust stiffness with wheels, bars, stem, maybe even cranks to a certain degree.

Reply

Varaxis
+1 Cr4w
Dan V  - Feb. 23, 2018, 1:51 p.m.

When it comes to increasing the strength of the bike, stiffness is the answer. Materials can only withstand so much stress before they yield and no longer return to their original form. The problem is determining how much stiffness is appropriate, as too much leads to a poor experience.

The holy grail is holistic design. A complete bike designed as a system which is optimized for a certain rider, riding style, and terrain. Ideally, riders wouldn't feel a desire to change big things out. If stiffness was properly tuned as a whole, a rider shouldn't consider swapping a Fox Float 34 with a 36, citing that the flexy fork is holding back the stiff frame. The opposite shouldn't be felt either, going weight weenie since some parts feel like overkill and make the bike feel sluggish. 

Categorizing bikes based on travel, geo, and/or other simple parameters should be eliminated. One clyde's XC bike for forest riding could be considered one lightweight guy's aggressive trail bike for hard rocky terrain. Maybe they just have to advertise this relative stiffness, or its duty level (between heavy duty or light duty), between bike models. One bike might be a moderate duty 160mm long legged all-rounder bike (e.g. Marin Wolf Ridge), while another bike could be a heavy duty 140mm hard hitting speed demon 29er Enduro race machine (e.g. SB55); categorizing doesn't show the bikes for what they are individually. People don't have time/attention span to read wordy reviews, and these end up being bunched into the same category at first glance and prematurely judged based on narrow-minded bias (e.g. believing 160mm travel is overkill or that 160mm bikes demand to be ridden like FR/DH bikes). The closer I examine the bikes, the harder it should be to group bikes together--I can't say a Radon Swoop fits into the same category as a Marin Wolf Ridge just by looking at it on paper (inc. reviews and linkage analysis). I can only confirm it if I ride them back to back, but I can make a solid prediction if I had more context such as riding many other Radon bikes, a Polygon with the same susp as the Marin, and bikes with the same spec.

Having shoot-outs between bikes optimized for different things is quite a demand. Between an all-rounder Orbea Rallon vs gravity-oriented Evil Wreckoning, the bike that wins is the one that suits the rider, their riding style, and terrain best. A beginner looking to overcome their DH fears, someone with all-around skills looking to replace a quiver, a DH junkie that wants to session local trails... we all know this, but how do we get a personalized answer? Should we expect a bike shop salesman to figure this out, instead of trying to move what's in stock?

Reply

jitenshakun
0
Jitensha Kun  - Feb. 23, 2018, 2:41 p.m.

Geared up I'm 230lbs on the bike and this new gen of "stiff" bikes are about right for me.  It isn't that long ago that road riding meant watching the BB sway back and forth and trail riding meant listening to the pivots creak.

Reply

dorse
0
The Big Picture  - Feb. 24, 2018, 12:38 p.m.

If I never hear the word stiffer in  bike advertising again. it will be tooo soon.

Everything is stiffer right.

Reply

dave_f
0
dave_f  - Feb. 28, 2018, 9:59 p.m.

What a lot of people miss is that lowering (or increasing) spoke tension has no effect on wheel stiffness -- unless the spokes are going completely slack at times, which might be happening in downhill racing.  It would definitely shorten the lifetime of the wheel.

As far as frames go, it would be nice if frame manufacturers would modify the tube cross-sections/layup depending on size, otherwise a smaller frame ends up being stiffer than a large one. Just the opposite of what would make sense.

Reply

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