Monday, 15 November 2010

Cross Technique

When you read this bear in mind that I've ridden on a cross bike exactly once. That was on Saturday at Vint Hill, when I did a pre-ride lap wearing a pair of tennis shoes. Tennis shoes and Eggbeater Candy pedals go together like peanut butter and relish, which is to say they don't go together at all, and I usually had some of at least one foot on the pedals. Couple that with a 2" long by 3/4" deep gash on my right instep from stepping on an oyster sheel while on vacation, which I definitely should have gotten stitched but that would have meant staying out of the water and that obviously wasn't going to happen. Every time my right foot slipped forward, which was every few moments, a pain burning with the heat of at least a very warm summer afternoon coursed through my soul. That's my CX experience.

On the other hand, I have watched quite a bit of CX racing this year and I usually watch things from the perspective of having been a pretty successful sailing coach for a while. This means I'm somewhat good at identifying critical differences.

We were set up right by the (very tight) zig zag turns at Vint Hill, and I knew that we'd see this section approached with a lot of different styles throughout the day. The more novice categories did them about how you'd expect - tentatively, with more enthusiasm and effort than discernable technical prowess. I say that not to criticize - everyone who raced did it better than I did when I did it. There were some riders who did them rather smoothly and quickly, but I thought we'd see much different technique later in the day. The A masters and elite women went through more quickly and smoothly than any previous fields had done, but still I thought we'd see something very much different out of the elite men.

It turns out we didn't. I'd half expected the elite men to do some sort of tail whip thing, which I would have expected to see in a mtb race. They didn't. Maybe cx brakes are so woefully underpowered (they definitely are not powerful) that this is an untenable technique, maybe I'm on crack for expecting to see it.

There was, however, one clear technique difference that distinguished Joe D, who won the men's elite race pretty easily (**Jared if you read this and are offended by it I'll explain below), from everyone else. This section was preceeded by a momentum downhill, and making the first turn required braking. The exit of each turn pointed down, while the entry to each turn was on a rise. I closely watched what gearing people were using, figuring that this would be a key differentiator. To simplify the discussion I'm only going to talk about the elite men, but the difference is relevant to every group I watched once I started looking for this.

Joe, like all the elite men in the lead group, was on the big ring every time through this section. I think Patrick Blair was on a 1x front setup so we have to eliminate him as a data point. Going through a section like this, my instinct would be to be in a gear that would give me something to pedal against when my back was gaining momentum out of the turns and pointing down. Most people did this, and were on the big ring and like 3 to 4 down on the cassette. EVERY TIME I watched Joe go through, he was fully cross chained to his largest cog. EVERY TIME I watched him he took a pedal stroke or two through the apex of the turn, and then backpedaled, ratcheting his crank into desired position for pedaling out of the bottom of the transition between the turns, and then quickly took a couple of pedal strokes into the turn. Most of the time, these pedal strokes were into his brakes, such that the bike was always ready to accelerate by his just easing off on the brakes.

In addition to offering what seemed to be greater speed and acceleration control, Joe's technique seemed to offer handling advantages. Other riders, pedaling into harder gears out of the bottom of the transitions and into the turns, got stood up and pushed forward as they tried to get on top of the bigger gear. Weight high and forward into a hard, tricky turn is not way to go through life. Joe, by constrast, stayed low and aft on his bike, and was more easily able to steer through the turns. I saw two riders do the "crumple" fall through these turns, pretty much definitely because they were really high up and weight forward.

There are a few caveats to these observations. One is that Joe was always in the lead. Jared was always close on Joe's wheel into the section, and I can't yet net out what affect Jared's relative position would have had on his technique. Other racers were unaffected by traffic through the section. Also, my observations are based on watching starting a few laps in - the lines were learned by that point, and didn't seem to change too too much as the race progressed. So whether consciously or not, everyone was using a chosen technique - not random.

To be able to execute this technique, your gear has to be very very dialed in. To be able to back pedal (quickly) while fully cross chained on very bumpy terrain without throwing your chain requires a really dialed drive train. Props to Joe's mechanic. Second, Joe is able to accelerate his legs REALLY quickly, so that he's accelerating his bike through rapid leg speed rather than torque. Not everyone has the leg speed to pull this off, but it's something that everyone can train.

It's not like Joe gained a huge amount each time through doing this, but he gained a few bike lengths each time. Perhaps more importantly, he was able to negotiate the section without relying on physiologically expensive torque to do it. I think it cost him less to go through this section using his technique than it did anyone else using the other technique.

Another observation is the Greg Lemond was right - it doesn't get any easier, you just go faster. It was exceedingly obvious that Joe was working REALLY hard for it, the whole race through.

**Finally to my explanation of how I come to call maybe a one second gap at the line an easy win. Joe led the entire race. Jared stuck to his wheel the entire race, which no one else came too close to doing, so enormous credit for that. But I could see the entire bottom straight and the entire top straight, and did not ever see Joe in any position other than driving the bus. Apologies if this observation is in error.

Apart from that, I'm significantly invested in learning all I can about cx frames. There is about an order of magnitude more variance between different cx frames than there is between road frames - BB heights, head tube angles, fork rakes, head tube lengths (some of these head tubes are WICKED short), cable routing, brake set up... It's sort of the wild, wild west.

Last for today, a grammar lesson from my mom about capitalization - capitalization is the difference between helping your Uncle Jack off a horse, and helping your uncle jack off a horse.

Have a good week, maybe some pictures later. We took tons.

No comments: