Wednesday, August 20, 2008

Racing - Tuesday Night and Short Cranks

I'll be the first to admit that I don't have conclusive data on fit, power, aerodynamics, and other things which can be scientifically measured. Okay, I have the SRM, a heart rate monitor, and I can see speeds and cadence. Not much else. And I probably don't use the tools as well as they could be used - for me it's just looking at numbers and seeing if I can get a few of them higher than before.

The problem with measuring scientifically, or at least in a repeatable manner, is that sometimes the measurements are made in such a way that the data ends up being irrelevant to the goal.

My blue car came with suspension braces and the marketing material boasted about how its stiff chassis. If the chassis was so stiff, why the suspension brace? How would you test such a thing?

Well, one owner (not me) did some suspension work and forgot to tighten the bolts on one side of his suspension brace. He found that whenever he went around a corner he'd hear a set of clunks. Ends up that his brace was clunking against the bolts. This indicates that there was enough chassis flex to move the brace a bit, and, consequently, if you tightened the brace down, it would help resist that movement.

So, likewise, I've been sort of experimenting, somewhat involuntarily, with different length cranks. After about 20 years using 167.5 mm or "normal" 170 mm cranks, I made the move to 175 mm cranks. I did so because the cranks gave me much more power, and, with a rider that had a significantly reduced fitness level, better top speed and mid-power "oomph".

I used the long cranks successfully, winning my first races in a long time, even earning medals (at least one of each color I think) in the Cat 3 CT Crit championships. But as I gained fitness I found myself wishing for shorter, faster cranks. I wasn't sure if sacrificing the ability to roll huge gears over medium hills would be worth any potential speed, but I decided to take the gamble.

I got some 170 mm cranks.

Problem was that these weren't just "cranks", they were part of my SRM. Changing them would cost, nowadays, upwards of $2500 (used) to almost $4000 (new).

There was no going back.

Unless... I used my old bike. Or the tandem. Or the mountain bike. Or the spin bike. All of them have 175s on them, and I don't feel like swapping them out. Well, my wallet doesn't feel like swapping them out.

So, recently, when I busted a spoke in my Reynolds clinchers, I moved my whole night riding rig over to the Giant (with 175 mm cranks) and went riding on the group ride.

I got killed.

I mean I couldn't go fast if my life depended on it. I felt like someone had put superglue in my bottom bracket bearings. It felt horrible.

Fine, my bike weighs 26 pounds or so, fine, it doesn't have fancy shmancy wheels, but still, this was a bit ridiculous. Ends up my seat was too high so I dropped it some. That helped. But I still felt dog slow.

I don't have any computer on it though so although I felt slow, I didn't know if I was slow. Ends up that slow on that bike is pretty fast - I did my Quarry Road loop pretty quickly on the "slow" Giant when it didn't feel very fast.

This brings us to the East Hartford Tuesday night races. I went back again yesterday, August 19th, bringing the Cannondale with its short cranks and tubular tires. I tried to warm up a lot because I wasn't used to the cranks. Coincidentally the last ride on the Cannondale was the prior week's race, and I hadn't downloaded the SRM data for either one. I'd get to see two races at once later that night!

I did some jumps in my warm up, trying to get my legs used to the 1 cm smaller circles. I felt fine on the bike though, a little more "spinny", a little more fluent. Felt fast in the tailwind, felt slow in the headwind. I had to work kind of hard to go more than 15 mph in the headwind and I started dreading the race. Small fields, no hiding, lots of wind.

A fellow racer, he of the "We Chase Blue" team, merged into the warmup loop. We've gotten to chatting while we spin around, but for this particular loop I wanted to do a big jump - I'd spent the last two loops steeling myself for this effort. So the first words out of my mouth were me saying that I had to jump.

"This isn't personal but I need to do a jump."

He laughed, I jumped.

We rolled around after, talked about his last race, a gear problem he had last Tuesday (fixed now), stuff like that. We went and watched SOC win his race, attacking the break and rolling in about 10 meters in front of the next guy.

Then we raced. I had a lot of fun going through the corners. Cornering in groups is something I don't do frequently, and I got to the point where I was pulling next to riders, looking over their lower back, and sighting down the exit of the turn by doing that. I experimented with cornering hard, once going over the manhole cover (both tires slipped sideways - better to go inside or outside), going wide a lot (fine), going inside (fine), and pedaling a lot (fine, but maybe I should have rested my legs instead).

Except for one guy who seemed to have a hard time cornering (he'd turn in early, swing wide, and didn't weight the front enough to prevent the "wide" bit) who almost ran me into the curb twice, it was good. Some other guy seemed to be dizzy and almost took himself out twice, but I can't really complain about that since I almost took out he of We Chase Blue on the warm down lap doing exactly the same thing, my bars swinging left somewhat spontaneously as I lost all sense of balance.

I did focus on staying on the drops, my hands a bit uncomfortable but my back and neck fine - although I started getting dizzy like I'd mentioned before. I don't stand enough on flat courses so I tried to stand a bit more than normal.

I started cramping about 25 minutes into the race, starting to regret doing that third and last jump. I tried to drink water but I had no electrolytes, no sugar. I kept at it though, as first my left calf started twinging, then my right, then, in the last five laps, my left quad started to go. I started dropping my heel to stretch out my calf, started using much bigger gears to avoid spinning, and tried not to make any unnecessary efforts.

I also kept checking my watch. When was the 45 minutes up and the lap cards out? 7:20? 7:25? It seems I was looking every lap and getting more and more impatient with the lap card folks.

Finally, at about 7:30, the cards came out. Well, I missed 5 to go, but I saw it was 4 to go. I rolled up to the We Chase Blue guy and told him I was cooked. I also rolled up to SOC and told him the same because he'd been trying to look after me in the race, and I didn't want him to be looking after me while I cramped right out of the race.

The laps wound down pretty quickly, and with two to go I was pretty far back for the group - 10 or so back in the 20 or so field. I moved up a bit, decided that my legs weren't really good for this, but the adrenaline (and the focus necessary to take all the turns smoothly and aggressively) kept me from sitting up.

But, of course, at the bell, I was sitting in the field, perhaps 10 or 15 back, and feeling like I had maybe 5 or 8 seconds of sprint in my legs. We flew through the first and second turn, a pro to my inside letting me ease ahead of him in the second turn. The field went pretty wide in the third turn (with manhole cover) and I tried to stay out of the wind by staying left, to the inside.

We passed the spot where Secondo jumped last week, then where I jumped. Guys were sort of milling around, a group of maybe five detaching slightly. I think they were the break, and although I sprinted last week and no one complained, I wasn't sure of the ettiquette of sprinting when a lap down. The left (sheltered) side was completely clear though, like five feet worth, and just screaming "Jump here! Jump here!" You know, like a little kid in gym class. "Choose me! Choose me!"

I listened to the gap, waited until I thought the line was prudently close, and sprinted into the superhighway along the left side fence. I rolled by the guys milling around in the front and rolled to the line, sitting up at some point, not throwing the bike, not doing too much. I thought I sat up well before the line but it never appeared so I think I sat up after the line.

Then, after the aforementioned almost-taking-out-We-Chase-Blue, some congratulatory words to SOC, and escaping with only two mosquito bites, we left. After we got home I downloaded the data from the two East Hartford races.


In my crampy 10 second sprint, I didn't break 1000 watts, essentially a moderate effort if out of the saddle. Not impressive, but at least I have a benchmark for me for a poor sprint. As a reference point I'd make the same effort when responding to P123 surges at Bethel up the hill.

I did do 1583 watts in one of my warm up sprints, my max effort ever (!!), and I did 1400+ in another one of them. The other two "sprints" were more form-sprints and I did only 800-something on one, 600-something on another, focusing on rocking the bike rather than going fast, getting ready to do the bigger efforts.

In contrast to my crampy sprint this week, last week (when I felt good in the sprint) I did a 20+ second sprint, holding 1000+ watts for 10 seconds, over 900 watts for 20 seconds, and peaking at a somewhat normal 1300 watts in the sprint. Nothing great (1450+ would be really nice) but sustaining the effort is good, and in races it seems I don't have the same peak power as I do in isolated sprints - in the past few years I haven't gotten the whole "sprint 100%" thing down in a race situation.

So, it seems that when I went and got on short cranks after being on long cranks for about 6 hours, I had much more power than normal. Is this causual? I don't know. Is it correlated? Yeah, because it happened.

But I don't know how to interpret this data.

One more week of East Hartford. Then I have to start looking for races. There are other things on the horizon as well, significant things which are not cycling related.

But tonight there's a group ride. And I'll be using the Giant with its 175s. Can't hurt for next week, right?


Anonymous said...

Crank lengths will be debated to the end of time. The truth is, riders adapt. I've used anything from 165mm to 180mm and am 6'2" tall. I like the idea of shorter cranks in order to spin-up quickly and more easily hold 120+rpms for long periods.

Keep on posting,

Anonymous said...

I was going to send you an email but I guess I'll do it here.

Due to my crash, I hadn't really ridden much summer. I've gained 5-10 lbs which I want to shed before next spring and I haven't really fit myself to my bigger frame in the real world.

I went out for a 13 mile ride the first day after being back on campus. I was seeing similar speeds to what I saw earlier, but my recovery and climbing sucked. I was winded very fast after a hard effort, but my cruising speed was about the same maybe around a mile less so not a big deal.

I did try a sprint though and I hit my fastest recorded sprint at almost 36 mph on a level road after gaining some momentum on a downhill.

The kicker?

It wasn't even close to the hardest effort I could have mustered...


-Young rider.

Anonymous said...

PS- Congrats on breaking your sprint power record!

Sweet deal!

Aki said...

YMCA - I still don't know about crank arms. Longer for training, shorter for racing? Adjust for different terrain, sort of like using a TT bike for flatter TTs and a light bike for uphill TTs? So rollers means long cranks, flat means shorter, and hills... well, I can't climb anyway so I'm lost there.

YR - I think your new frame with more appropriate sizing will do wonders. You can focus on getting super comfy on the bike, super comfy in a group, hone handling skills, and basically build a wide, solid base from which you can start racing again next year. And thanks on the power :)