Stance/bottom bracket issues

[SadieKate]

This is an old, old article so the measurements quoted for cranks are far out of date, but the info about q-factor is good. Since the crank/frame compatibility may be an issue, looking at spindle length in the pedal is good. But you have to make sure your feet are small enough not to wear on the crank arm.

http://www.sheldonbrown.com/bridgest...ne-1991-13.htm

[fidlfreek]

Awesome article!

Hey! I know that the triple is/was making the q factor worse (159mm fyi). It was causing me knee pain. Or at least I think it was. It is still a problem on the FC-6600 crankset i tried last month (Ultegra SL compact) which has the same 147 or 146 q factor as all the higher end dual chainring shimano cranksets. It seems like the only way this gets better is with either 1) an older school Shimano crankset aka older than 7700 where the q factors go down to 140 or lower. Any other ideas ladies? My beautiful Look 585 optimum is sitting here all built and ready to go except that I can't decide on which crankset/bb to order. Agh! I do not want to order an older crankset and compromise on stiffness, power transfer, weight etc! Help!

I am a very small (5'2 100 lbs) woman and I use a 140mm measurement saddle (which is very narrow as far as women are concerned)....so I'm thinking that my whole setup is just narrow. My feets are quite small as well and since I have a decent pedal stroke and no weird ankle things I have tons of clearance with my crank arms/chain stays etc.

[fatbottomedgurl]

Something I heard from my LBS owner regarding triples: She always recommends a triple on any bike 50cm and under. The reason is that the shorter distance from the front chainrings to the cassette on a double will not provide enough clearance for the chain as it passes from the smaller chain ring to the smallest gears on the cassette. The chain ends up rubbing on the big chainring and causes shifting issues. Just something to think about since you are a short gal. I wonder if anyone here has had an issue with that.

[lunacycles]

What causes chainrub on extreme crossover gears has nothing to do with frame size. Very short chainstays (like under 405mm) do in fact often create chain rub issues, but smaller bikes tend to have the same chainstay length as larger bikes, assuming 700c wheels are being used. There is generally no need nor value in utilizing shorter chainstays on smaller bikes (unless you are using smaller wheels), and afaik no big manufacturer does this on their smaller frames to any significant degree.

You are actually less likely to have chainrub on the extreme gears (small/small or large/large) running a double rather than a triple.

Chainstay length has no effect on q factor.

The problem with trying to manipulate q factor by using older cranks and bottom brackets is that it can adversely affect your overall shifting, as manufacturers need to have their chainrings (and therefore q factor) in a certain position relative to the cogs for optimum shifting. Manufacturers design whole groups to work with each other, and there can be issues mixing and matching components from one model year with an older model year. Just the proverbial "heads up."

Because we generally have slightly wider hips, I have not found that a lot of women, even small women, have q factor issues, not to say that you aren't.

I might recommend you 1) get measured. your hip width/lateral distance between your femurs will largely determine your ideal q factor. Without measuring this, it is hard to know if q factor is really the problem, 2) re-adjust your cleats, or try a pedal with full float (like speedplays) so your knee is not locked in at any predetermined angle. That might make a bigger difference than you realize.

Just some thoughts.

[fidlfreek]

lunacycles you're awesome I am going in for a measuring on Friday.

[Bluetree]

I have had similar issues with narrow hips. (Def not a baby-maker!!!)

I switched from Speedplay Xeros to the free-float X-1s and am much happier.

[fidlfreek]

See, I'm not the only one! Its good to hear about the speedplay. I used them when I first started riding and then moved to Keo but am still using the 9 degree red cleats. Maybe not the brightest plan....on second thought.