Road Bike, Cycling Forums banner
1 - 5 of 5 Posts

·
Registered
Joined
·
2,076 Posts
Discussion Starter · #1 ·
I had a revelation when getting a bike with a triple. I didn't really need the lower gears (ahem) but found it was much more comfortable in terms of Q-factor. I am somewhat bow-legged and really notice the change when going from a bike with a triple on it to a single speed. The lower Q-factor on the single plays hell with my ankle. Can I just run a longer axle through it?
 

·
Registered
Joined
·
10,161 Posts
no...

A longer spindle on the BB will foul up the chain line. You can get some increase in the tread width by installing washers on the pedal axle to move them further apart, but not as much as the typical 10-12mmm increase you get with a triple.

There are pedal extenders made, but they create a much larger increase in tread width.

http://www.bikemania.biz/KNEESAVER_PEDAL_EXTENDERS_p/bikescorknee.htm

You may want to try some Lemond cleat wedges to help correct your leg alignment.

http://www.lemondfitness.com/products/lewedge/index.html

I assume you use the same shoes on both bikes, so moving the cleats toward the inside of the show would not eliminate the difference between the two bikes.
 

·
Unlabeled
Joined
·
3,729 Posts
chainline off by a few mm does it matter?

rcnute said:
I had a revelation when getting a bike with a triple. I didn't really need the lower gears (ahem) but found it was much more comfortable in terms of Q-factor. I am somewhat bow-legged and really notice the change when going from a bike with a triple on it to a single speed. The lower Q-factor on the single plays hell with my ankle. Can I just run a longer axle through it?
You are going to change your chainline by 5 mm or so,; it won't matter much. You could respace and redish your rear wheel--not hard to do to only move the cog 5 mm.

I'm skeptical however, that you can tell a difference in spreading each foot 5 mm out from the center of your bike. I ride a single, double, and triple and can't tell the difference in Q.
 

·
Registered
Joined
·
10,161 Posts
Wrong...

Redishing the wheel has nothing to do with the chainline. The hub is fixed on both sides and dishing has no effect on the relationship of the cogs to the crank. Dishing centers the rim between the droputs.

Putting a 10mm longer spindle on a double would make the chainline nearly the same as a triple and make the little ring and largest cog angle too extreme.
 

·
Unlabeled
Joined
·
3,729 Posts
Think a little more before posting

C-40 said:
Redishing the wheel has nothing to do with the chainline. The hub is fixed on both sides and dishing has no effect on the relationship of the cogs to the crank. Dishing centers the rim between the droputs.

Putting a 10mm longer spindle on a double would make the chainline nearly the same as a triple and make the little ring and largest cog angle too extreme.
You are so eager to find something wrong that you don't always think things through. If you re-space the hub by using shorter spacers on one side and longer spacers on the other side it shifts the position of the hub in the dropouts to give teh correct chainline. However, this moves the entire wheel and you need to re-dish the wheel to center the rim and tire.
 
1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top