Road Bike Racing - fixed gear training question: crank length

Lots of fixed-gear riders (Sheldon Brown, and the crowd form the SS/fixed forum) would suggest that running 165mm to 170mm cranks are the norm (faster spinning, less risk of pedal strike, etc.) But if the goal is just fixed gear training for road racing, should your crank arm length be different from your road bike?

I'm asking because I ride 175mm arms on my road bikes, and I don't like the idea of having my fixed gear bike fit differently...

Thx.

Might depend on the geometry of the bike. Most track bikes have a higher bottom bracket and because of that some prefer a slightly shorter crank. But unless you're worried about pedal strike, I'd say run the 175s. Shouldn't be a problem if you're careful on corners. (I've never once had a real pedal strike. A few times, on clips and straps, the edge of the strap just barely brushed the ground. That feedback alone was enough for me to just gauge it from then on).

The higher bottom bracket shouldn't affect crank arm choice. It's just there for better pedal clearance (on a velodrome). I'd say stick with 175s if you just want to train on the road, but if you're looking to practice spinning at a high cadence, you'll have an easier time with that on shorter cranks.

The higher BB will also help with pedal clearance on the road-- it's helpful at low speed in the corners on a track, but at higher speeds in turns on the road (when the bike is leaned over).

I'm not sure it's that big a deal to switch crank lengths. I ride 172.5 on the road, and 165 on the track, and probably half my mileage (and almost all my racing) is on the track. It's usually not that noticeable, and only takes a few minutes to adjust usually.

Same, 172.5 on the Road, 165 on the Track. Really doesn't feel that much different.

175 road
170 track

Somewhere I read crank length is over-rated. I believe it.


chuckle chuckle

I use 175 mm cranks on the road and had a winter bike with 170mm cranks. I could definitely feel the difference, and I tended to pedal a cadence of 5 or 10 rpms higher with the shorter cranks. So, in the name of specificity of training I put 175mm cranks on the winter bike. When I got a track bike with 165mm cranks for winter training, I made the same switch. It makes the transition back and forth from bike to bike feel less weird.

if you are going to be out on country roads where you wont have to worry about pedal strike, go with the 175's if that what already feels good.

175 road
170 track

same

With a fixie, it's also about being able to maintain a faster cadence 'cause you don't have a choice. Minor case in point - late last season, I was commuting home on my fixie when one of the faster groups from the local weeknight hammer ride passed me. I decided, heck it's mostly downhill on this stretch and I should be able to keep up with them until I hit my turn off - and with a commuting rig complete with a mirror and fenders, it'll be my personal FRED moment. Too bad my legs refused to do the necessary rpm! I even kept looking for a taller gear as I spun out and watched the ride pull away. :lol:

Shorter cranks should let you pedal at a little higher cadence.

The higher BB will also help with pedal clearance on the road-- it's helpful at low speed in the corners on a track, but at higher speeds in turns on the road (when the bike is leaned over).

I'm not sure it's that big a deal to switch crank lengths. I ride 172.5 on the road, and 165 on the track, and probably half my mileage (and almost all my racing) is on the track. It's usually not that noticeable, and only takes a few minutes to adjust usually.
+1. I go between 165's on the track and 170's on the road and I don't think about it when I'm riding. My opinion is you should go smaller on fixed. I would say 170's but it's your bike.

Don't go with a 165, because you'll love it so much that you'll want one for your road bike.