Originally Posted by Raedeke
How do I figure the proper width of the bottom braket needed for a 9 spd/double.
I have a 68-109 in there now, but I'm getting chain rub on the larger chain ring while the chain is in the small ring and in the small gear in back. It just looks like the crank is pulled too far into the frame.
I have no problems with clearance from the chainring to the frame.
Should I have a 118 on there?
Or could there be other problems?
Thanks -
You have the Correct BB in there.You shouldn't be in the small small.You could even get that same rub in the small and second cog.Just don't do it.