Crank Length
 

I know this has been talked about here before, but I can't seem to find what I'm looking for. Currently I'm running 170s on both my track bike and my road bike. I'm always seeing all of this stuff on here about people running 165s on their track bikes, or maybe just fixies? Anyways I was thinking about getting some new cranks and was wondering if there was actually an advantage of running 165s vs 170s while racing on the velodrome. (I don't ride my track bike on the street. That's what the road bike is for.)

I'm 5'6", I believe I have a 30 inch inseam, and I'm riding a 49cm Motobecane Track which I believe is very similar to the Fuji Track Classic.

As long as you feel comfortable on your bike, and arent having pedal strike I would say stick with what you have. Those two are pretty important when it comes to crank length, everything else is all about guessing and science in a vacuum.

Thanks, that's kind of what I was thinking. I actually found a pair of 165mm cranks (some cheap ones) in my spare parts bin today. I'm gonna put them on and just see what it feels like.

I dont know if Id do that. It would definatly require raising the seat, probably adjusting it front to back, and maybe moving the bars around. If you realyl want to try it out Id wait till the off season so you have lots of time to play.

Have a look in here: http://www.bikeforums.net/showthread...-bike-frame-up

I'd suggest 165mm based on your height and not knowing about your riding style.

If you try the 165s, I would suggest not raising the saddle, but moving it back a little.

Hmmm.... well I put them on there, still need to adjust the saddle. I'm gonna give it a try tomorrow, I'm going to a training ride at the track, so it'll be a good test. Btw, I tend to lean towards the higher cadences on my road bike. Not to sure what I hit on the track bike as I don't have a cadence sensor on it. But when I TT on my road bike I tend to ride in between 110 - 120 rpm. I guess I'll just have to find out myself how it feels, I'm just worried about not setting my saddle properly and feeling more of a difference from that then the cranks.

Don't sweat the saddle height.

The 5mm shorter cranks will give less leg extension (making your saddle feel lower). But people often ride with slightly less leg extension on the track, so it might net out to the same as far as seat post extension.

Depends on the track and the type of racing you do. If you're riding MTV, Northbrook, or Kenosha, you can probably ride pretty much anything for anything.

Home Depot Center is 46 degrees and doesn't restrict crank length-- we have people riding anything from ~150 (kids) to 175 (mostly pursuiters) and one guy riding custom 190s or something (crazy long enough that it actually looks weird). If you're on long cranks on a steep track you just have to be aware of how it may limit your riding-- I've tapped a pedal on the banking at Blaine with 165s and not gone down. I don't think I've ever seen anyone at HDC touch a pedal to the track without being on their way down already-- the wood is less grainy and ends up being effectively slipperier than at Blaine. If you're riding a lot of match sprints on steep tracks you probably want to be on the shorter side, though there's a lot less low speed stuff in sprints these days. I have a friend who rides 175s in a big gear on his pursuit bike at HDC, and when we're at the balustrade together I have to keep the speed up higher if he's behind me and we're supposed to be in zone 1 or 2.

Pedal strike is a combination of track angle, crank length and BB height. You really need to know all of those to know if there is going to be a problem. If you are averageing 110-120, then you should be hitting near 150 in the sprints (dependant on your gearing and style). It sounds like 165 would be good for you.

I just ride at Northbrook and Kenosha, I'm not concerned with pedal strike, as I don't seem to get close even with 170s.

Hmmm, haven't adjusted the saddle yet so maybe I'll just leave it and then change it if I feel that I need to.

http://weightweenies.starbike.com/fo...k+crank+length

Bit of a dredge but 11.4's post (scroll downa bit) deals with the biomechanics of what's going on.