Harry Phinney

The first thing is to determine exactly why the chain line is off. The chainline should be 42.5 mm from the frame centerline according to my trusty old Campy catalog. Carefully measure the distance from the center of the chainring teeth to both sides of the seat tube and average it. The inside faces of the dropouts should be 120 mm apart, and the center of the cog teeth should be 17.5 mm from the inside face of the right dropout (60 mm from the dropout face to the frame centerline minus 42.5 mm from the centerline to the cog teeth). Finally, wrap a string from one dropout, around the head tube and back to the opposite dropout. Measure from the string to the seat tube on each side – the measurements should be equal. I’ve read reports of Fuji Pro track bikes that required overly long BB spindles to enable the chainring to clear the chainstay, but I don’t have any personal experience with them.

Harry Phinney

From: obra-bounces@list.obra.org [mailto:obra-bounces@list.obra.org] On Behalf Of Robert Anderson
Sent: Tuesday, May 12, 2009 9:32 PM
To: obra
Subject: [OBRA Chat] Clunky track bike question

OBRA trackies, I have a new Fuji Track Pro that I started racing late last year. The bike has a total of about 70-100 miles on it. From the get go, it's been a noisy as if the chain is being forced onto the sprocket during certain parts of the rotation. If threw if up on the stand and took a close look at it this evening and found that the chain is tracking to one side on the rear sprocket. and in one part of the chain it's even closer to the edge. The rear sprocket is not beveled at the tips of the teeth, but rather the same thickness from top to bottom. It appears that I have a couple issues that need to be addressed, but I'm not sure how to fix them. 1) The chain allignment is off, and 2) perhaps I need to file the teeth on the rear sprocket, creating a beveled tip (or replace it with one that is beveled).

Any advice is appreciated. Thanks in advance.

--
Rob Anderson
riznob@gmail.com

scott hill

try bolting the chain-ring on whichever side of the crank that helps align the chain angle. i had this same problem on a trek track bike and i had to bolt it on the inside and that solved the problem. as far as the cog goes what type is it? i would only by Dura Ace cogs. they are a little more expensive but they last forever. also check and make sure your chain is not to tight. spin you rear wheel and find the chains tightest point and adjust from there. if you dont then i can bet that your chain is to tight and will make a lot of noise. hope this helps.
 
scott

--- On Tue, 5/12/09, Robert Anderson wrote:

From: Robert Anderson
Subject: [OBRA Chat] Clunky track bike question
To: "obra"
Date: Tuesday, May 12, 2009, 11:32 PM

OBRA trackies, I have a new Fuji Track Pro that I started racing late last year. The bike has a total of about 70-100 miles on it. From the get go, it's been a noisy as if the chain is being forced onto the sprocket during certain parts of the rotation. If threw if up on the stand and took a close look at it this evening and found that the chain is tracking to one side on the rear sprocket. and in one part of the chain it's even closer to the edge. The rear sprocket is not beveled at the tips of the teeth, but rather the same thickness from top to bottom. It appears that I have a couple issues that need to be addressed, but I'm not sure how to fix them. 1) The chain allignment is off, and 2) perhaps I need to file the teeth on the rear sprocket, creating a beveled tip (or replace it with one that is beveled).

Any advice is appreciated. Thanks in advance.

--
Rob Anderson
riznob@gmail.com
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Robert Anderson

OBRA trackies, I have a new Fuji Track Pro that I started racing late last
year. The bike has a total of about 70-100 miles on it. From the get go,
it's been a noisy as if the chain is being forced onto the sprocket during
certain parts of the rotation. If threw if up on the stand and took a close
look at it this evening and found that the chain is tracking to one side on
the rear sprocket. and in one part of the chain it's even closer to the
edge. The rear sprocket is not beveled at the tips of the teeth, but rather
the same thickness from top to bottom. It appears that I have a couple
issues that need to be addressed, but I'm not sure how to fix them. 1) The
chain allignment is off, and 2) perhaps I need to file the teeth on the rear
sprocket, creating a beveled tip (or replace it with one that is beveled).

Any advice is appreciated. Thanks in advance.

--
Rob Anderson
riznob@gmail.com