front chainline with same BB & crank but diff. frame
05-26-07, 11:59 PM
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front chainline with same BB & crank but diff. frame
i think this was a silly question..
Last edited by HappyHumber; 05-27-07 at 09:25 AM. Reason: Upon further thinking & tinkering...
05-27-07, 09:36 AM
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Why was it silly? The chainline can vary with the frame even if the same crank and bb are used.
05-27-07, 09:53 AM
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hello
The question is too vague.......your crankset chainline distance (distance from middle of bb spindle to the big ring, for instance) will always remain the same when using the same crank/BB combo, regardless of frame.
For instance, my track crank/BB combo gives me a 42mm chainline regardless of what frame I mount them on.
For instance, my track crank/BB combo gives me a 42mm chainline regardless of what frame I mount them on.
Last edited by roadfix; 05-27-07 at 10:12 AM.
05-27-07, 10:03 AM
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Originally Posted by HillRider
Why was it silly? The chainline can vary with the frame even if the same crank and bb are used.
Ah..... just in the time that elapsed from my original post with my inexperienced meditation on the matter; combined with a lack of replies I kind of thought I had answered my question myself anyway.
The same combination of bb & crank, previously giving a 43mm front chainline on an out-of-the-box Surly Steamroller, on the old 80s MBK frame receiving them as new hand-me-downs, gave me 46mm at first. I quit for the day on the tools and posted originally without tinkering some more.
My original question (now deleted) arose out of whether my assumption about all seat tubes are all mounted centrally on the bb shell in the frame was correct or not.
Picking up the tools again today, Australian daytime, and actually torquing things down a lot harder gave me something closer to 44mm.
05-27-07, 10:36 AM
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My point was the required chainline can vary with the frame and rear dropout spacing.
True, for a given bb and crank, the chainline, relative to the seat tube center, will remain the same on all frames.
True, for a given bb and crank, the chainline, relative to the seat tube center, will remain the same on all frames.
