crank length
 

Almost done with a single (actually double because I'm using a Paul MELVIN) speed and I wondered if in the future when I upgrade the cranks if anyone has a preferable length. This is especially important for cornering because I would like to do some work as a courier and I need to be able to manuever and not worry as much about catching a pedal on the ground.

What length does everybody out there use?

Thanks!

lrschum

I use 170s and have never had a problem cornering. Nary a pedal hits the ground except when I eat pavement.

is this an MTB or road SS application?

Road, it is a 56 cm frame w/ 700c wheels (tires are 30c kenda cyclos).

since it is an SS application, any size should be fine as long as you COAST thru the corners - that is up to you. Shorter cranks are essential when cornering fixed.

Size of pedals matter, too, if you're talking about cornering clearance...something like an Eggbeater is less likely to clip the ground than say a platform w/toe clips & straps. I run 170 cranks and have no issues, but the frame is a track frame so BB is higher than a road frame...your results may be different.

Well, I would like to be able to pedal through corners at least to some degree because at present I basically have to stop pedaling the moment I want to turn because I will grab a pedal on the ground.

I want to see if I could go shorter without losing too much spinning power.

the smaller the arm, the better the spin. the longer the arm, the more leverage you will realize

It's something I haven't seen many people mention, probably because it becomes intuitive once you are fixed (someday you all will be... muah ha ha ha)

Just don't freakin lean when you turn. It's better for winter riding on ice too. Try to set your spin so that the pedal that's going to be on the inside of the turn is on the way up on your way through the turn. Put hard push back (nowhere near enough to skid) on that pedal as you go through the turn, preferably right as you want to hit the 90 degree mark (summer only, just slow down and stay vertical on ice). A quick, vertical turn is better for avoiding traffic too.

The nice thing about riding a track bike on the streets is that it's so much more responsive that you can go around the corners with just a flick of a wrist. You don't need to usually dip at all...

Most of the scars on my pedals are from trying to squeeze to the right of cars and running a pedal into the curb - there's not much you can do about that.

Anyone else ever look at video of motorcycle racers and wonder how they can hit those corners leaned over so far? I've seen some where they're pretty much horizontal to the road....

i run 170mm cranks on my road conversion, and i'll basically eat pavement (and how!) before my pedals get within a couple of inches of striking. i'm pretty good at cornering too...a curiosity question that this thread just made me think of: how much does one's weight effect cornering ability?

I always put my inside pedal up on a turn (I ride XC so it's second nature), but I would like to be able to pedal during the turn so I can keep the speed going.

As to the weight, I think it depends on how flat or filled your tires are because my brother weighs about 70 pounds more than I do and he seems to be able to corner just as tightly as long as our tires are same relative inflation (i.e. his has more, but he weighs more). I know that I corner better when there is slightly less than normal pressure, so the tire compresses and grabs more during the turn.

Of course, this is different between pavement and dirt and mtb and road...

Leslie

Ya, I meant on my fixie. On my geared beater I used 175mm cranks, so I have to put the inside pedal up or it's CLANG!

Well it depens on your frame, although most road bikes have lower bb than mountin frames each is diffrent. I run 175's on everything, my Viscount frame clears the ground fine but my toe can hit the front wheel in a sharp turn. My Bianchi frame wont clear the ground but my toes dont get in the way of the front wheel. So it just depends, Perhpas you should shoot for the middle ground and find some 172.5's.

Thanks for the advice.

BTW, I love your avatar :D

"Anyone else ever look at video of motorcycle racers and wonder how they can hit those corners leaned over so far? I've seen some where they're pretty much horizontal to the road...."

gyroscopy

(and sticky rubber)

Nah - get yourself a set of Sugino 171s. Your bike will love you for it!

They pretty much have to lean that much, don't they? Seems like in a turn going that fast, if you tried to stay upright the bike would flip...

They also have really burly knee and elbow protection...

I'm running Suginos right now, but I'm pretty sure they're 175s (I have to put the peddle up on slight curves, so they are pretty long).

They make 171s too - not too short, so you don't spin as fast. I got these ones from Jintensha... I know goatmeal has bought bikes off of ebay just to get these cranks... It's 144mm BCD... They're purdy... They make a variety of lengths. I think the 171s are older... Wish I had a link to an image...

I am running a set of old 170 campy GS cranks from the remainder bin at my LBS on my fixed (a converted road frame), and pedal strike has not been a problem. But I have noticed that there is a tight spot and a loose spot in my pedal revolutions, and I wonder if that has anything to do with using road rather than track cranks. I have not really tried to fix it, but it is a little annoying. Any ideas if it is the cranks, the BB or something else entirely?

maybe there's a little too much slack in your chain? Or maybe i'm mis understanding the problem...

I have this same tight and loose spot on my Pista with all-stock drivetrain. Originally I thought the culprit was the rear wheel alignment, but that doesn't seem to be it. I also suspected the chainring, but I'm not convinced thats the problem either. I guess it could be the cranks or BB... For now I'm just dealing with it.

I would guess the chainring is out of round. Most are, though some much more than others.

This was my guess too. So I took off the chainring and rotated it 2 or 3 bolts so theoretically the tight and loose spots would be move. But the chain still seemed to be loosest in the same spot - when the left crank was between 12 and 3. Further testing was cut short by my lack of a chainring bolt spanner. When I get around to getting one I'll run further experiments.