The absolutely staggering thing is how much more wattage a Clydesdale cyclist can put out with proportionately size cranks. I mean staggering...

With clown cranks (175mm) you can't effectively climb, and a ridiculous cadence is the only way to try and move the bike. If anyone has ever put bigger tires on a Jeep without regearing you'll kind of understand the problem with cranks that are too short. While the cyclist may have power, the cyclist/bike can't get that power to the rear wheel.

You have to be careful with proportionately sized cranks. I deliberately didn't choose 215mm cranks, or even 210mm cranks. I went kind of conservative on my touring bike, and even more so on my tandem.

The problem is that any bigger guy probably played a little competitive basketball or football, and has stronger legs. You can get yourself in trouble all of a sudden pushing ridiculously high gears, which isn't good for your knees. The trick is to realize what your natural cadence is.

The problem is that what worked for Marco Pantani isn't going to work for a Clydesdale that is at least 100lbs heavier and probably at least a foot taller than El Pirate was, in terms of spin.

Zinn now rents adjustable cranks on the website. You can take different rides and set 'em for all kinds of different lengths to figure out where you "should" be. The problem is that any serious cyclist will take at least a couple of weeks to figure out their natural crank length after a lifetime on clown cranks. The trick is to find that perfect length...

I think it would honestly take me a month with the adjustable cranks to settle in. Then again, I'm the guy that bought a Look Ergostem because I like to keep dialing in fit across different bikes (and its instrumental in fitting women and showing them that their frame is just WRONG for them - top tube length).