How Did Gwin Win With No Chain?

People have been talking a lot about Aaron Gwin’s chainless downhill win. Do you think there is anything to the theory that full suspension bikes perform better with no chain tension affecting their suspension performance?

Sincerely,

Hot for Gwin

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Dear Hog:

Oh man. Thank-you Internet. This is a fairly technical question and Uncle Dave has some ideas, but thought it would be best to reach out to an expert on this subject. We asked a well respected, full suspension bicycle engineer, responsible for the design of countless kick ass, race winning bikes for comment. Here is what he had to say.

We have done a number of studies on this particular subject. We found that chainless bicycles are, in fact, slower – but only on flatter trails (you could graph this out). We also found a direct correlation to speed and use of brakes, with brakeless bicycles being the fastest. This test was performed in China on a set of stairs recently. 

So, from an expert, no, it doesn’t seem like Aaron Gwin won because his bike had no chain. But let’s dig in further.

Point #1 – Full Suspension Bicycle Design Science

Did you realize that many companies have put a tremendous amount of resources into designing their full suspension bicycles?  It’s true. A large part of what they try to do is:

• Minimize chain growth
• Minimize the effects of pedaling
• Utilize chain forces to counter some of the above effects

Old suspension bikes pedaled terribly. New suspension bikes don’t. They remain active under pedaling and they don’t bob a whole lot. Yes, designers have kept some of the pedaling forces in their designs to counter pedal induced bobbing…but that’s under full pedal load, not coasting through a rock field at 50 km/hr. Bikes remain active under full pedal loads, so why is the suspension action now compromised while coasting downhill? This makes no sense.

Point for Uncle Dave

Point #2 – High pivot idler bikes

Even though this theory doesn’t hold water with me, I’m going to help you with it. There’s a school out there that speaks reverently about high pivot downhill bikes with a “rearward axle path”. They’re amazing! You’ve never ridden a bike so smooth through the bumps! The interesting thing is that all of these bikes come with some kind of high mounted idler that essentially creates a zero chain growth suspension design. They’ve engineered chain effects out, both the good and the bad. And what if these bikes perform so well not because of the “rearward axle path” but because of this total lack of chain forces? Shit.

Point for the Internet

Point #3 – Slapping chains

This one caught me by surprise, but there is actually some kind of pseudo scientific use for Vital and all their g-out project photos, other than providing a few minutes of time wasted at work gawking at downhill bikes looking strange. Check out this thread here. Yes, okay. In this one here, under full compression, the chain does seem to be under tension. But the other 19? Chains slapping away (i.e. chains slapping away because they’re not under tension). No tension means no chain effects on the suspension. And this makes sense. What happens when you hit a big jump on your bike? Do you land and think about how quiet and serene everything is? Do you not eke out that last few millimeters of travel because your chain tension got in the way? Or do you bottom that sucker out while the chain bounces all over the place and makes all kinds of noise? The forces that cause your bike to bottom out are far, far larger than the forces from your chain.

But Dave. It’s not under full compression that the race is won. It’s on braking bumps and other smaller stuff that the suspension really shines. That’s where a lack of chain really shines!

Really? Okay. The last time I skittered across braking bumps my chain jumped all over the place i.e. no tension and therefore minimal chain effects on the suspension. But I’m going to spot you one, Internet. You win this round. But what do you think this magical lack of chain tension that you’re only obtaining because I’m being nice gains you? Like, a second a run? Two seconds? Never mind that race teams spend tens of thousands of dollars and man hours tuning their suspension to gain fractions of a second. If only those stupid idiots would realize there were seconds to be gained just by removing the chain.

Point for the Internet (because I’m being nice)

Point #4 – You can’t pedal

Are we forgetting that when your chains fall off, you’re unable to pedal? And even the steepest and gnarliest of DH courses have a bit of pedaling on them? And how many seconds are you going to lose by not being able to pedal, course dependent, of course. I’d be shocked if there was a DH course that didn’t quickly eat away the 1-2 seconds we’ve gained due to our insanely supple suspension.

Point for Uncle Dave

Point #5 – These are World Cup racers, not You

Have you ever read an article where some shmoe rides a pros bike? You have, right? And what is the first comment? Always?

Oh my god the suspension is so stiff!

These are World Cup DH pros. Their bikes are not set up for supple relief over braking bumps. They’re set up so that the riders don’t kill themselves when they hit massive holes, rocks, bumps and jumps. So now, all of a sudden, we’re winning races because we’ve obtained a tiny amount of increased suppleness? That makes absolutely no sense at all.

Point for Uncle Dave

Point #6 – This has happened before

Do you know how many times people have lost World Cup races because their chains broke? I’m thinking, quite literally, that this has probably happened one thousand times. One thousand times somebody has started a world cup downhill race, pedaled along, broken their chain, and then lost that race as a direct result of their chain falling off.  (Okay. Maybe not a thousand times. One hundred times? One hundred times this has happened.) And now, twice, people have had successful results despite losing their chains and people think that is the reason for their success? That’s just crazy. That’s like watching the Carnie calmly and easily throwing the ring onto the neck of the bottle and then spending your paycheque trying to win a stuffed bear because it must be easy to do because you watched it happen once.

Point for Uncle Dave

Sorry, Internet. Uncle Dave wins.

But why did he win? He being Aaron Gwin. Not Uncle Dave winning his imaginary contest.

Bear with me here. My scenario to explain this is going to plunge into an alternate universe with a cast of several characters. Sorry, but an outlandish Internet theory needs a similarly outlandish comparison to level things out.

Now, imagine this alternate universe. In it, everything is the same as it is now, except Tom Brady and Giselle have made their fortunes not as a quarterback and a supermodel, but as competitors in a reality TV show where they compete for the affections of a member of the opposite sex in front of a live audience.  They line up against 80-100 other similarly talented competitors, and rely on their charm, looks and other talents to sway a judge into determining they are the most superficially amazing humans present that evening. So, basically the Bachelor/Bachelorette but with successful people and a bunch of money on the line.

As you can imagine, Giselle/Tom Brady are really successful at this. They are charming and attractive and humble and they win a fair number of events. But the competition is hot! They have to work hard to stay on top and victory is no longer assured. And worst of all for them, they recently changed shoe sponsors and things haven’t gone well. But they’ve made a recent return to form and are a threat to win on any given evening once more.

But there’s millions of dollars up for grabs! Despite being Giselle/Tom Brady, man, they’re nervous when the competition comes around. What if they don’t win? What will people think? They won all those past events…what if they never win again? It’s a mental nightmare.

The night rolls on and its Giselle’s/Tom Brady’s turn. They walk out onto the stage, and just as they’re getting into the magic/witty banter/swimsuit portion of the evening, disaster strikes! One of their shoes falls off! And they’re wearing a ratty, holey, smelly sock underneath. Their night is over. Nobody has ever won a competition wearing a ratty, holey, smelly sock. It’s happened dozens of times before…for some reason people don’t think to put on fresh socks before a competition.

But Tom/Giselle keep going! Not only do they keep going, they’re thriving! All that pressure…it’s gone. Nobody can possibly win with a ratty, holey, smelly sock. It’s like a thousand pound weight has been lifted off their shoulders. They’ve never performed so well. They win! They’re the superficial champion of the night!

Now. Did they win because of their ratty, holey, smelly sock? Did they win because all expectations and nervousness and pressure were removed? Or did they win because they’re Giselle/Tom Fucking Brady and that’s what you do?

To finish off, I have a few more things that did not cause Aaron Gwin to win any race, ever.

Because Trek bikes are the best.
Because Eric Carter imparted some kind of Gandalf-like wisdom on Aaron Gwin through magic.
Because Specialized bikes are the worst.
Because Specialized bikes are the best.
Because his new suspension linkage is made of aluminum, not carbon fiber.
Because God told him to.
Aaron Gwin wins because Aaron Gwin is a bicycle racing animal.

Sorry,
Uncle Dave

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Hot For Gwin, because this is an Uncle Dave Special Report, you don’t win anything. Not anything besides this, that is. Your prize is being serenaded by Uncle Dave.

Sorry.

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Uncle Dave is thinking he needs a week off next week, after his insane production the last three days. Only your questions will get him back to the keys. Fire away…