[JohnE]

K, so I got a set of dog bones off Ebay. Payed way too much for them, but I got em.' So anyway, they dont fit on the spindle of the old XT BB in my shell (Spindle too short, will scrape on chainstay). Anybody know the correct size to go on an old Jamis Dragon (97)
Thanks-
JohnE

 

[indieboy]

what size do you have now? like a 105?
more than likely a 118 will do the job

 

[Wumpus]

Put the cranks on your current BB then measure how far you need to move the crankarm. You want about 3 to 4 mm of clearance between the crank arm and chainstay. Double that number and add it to the width of your current BB.

-OR-

This works for most older bikes. Attach the chainring side arm and measure from the middle of seattube to middle ring for a three setup or between the rings for a two ring setup. For a shimano drivetrain, that optimum chainline is around 47.5mm so subtract your measurement from 47.5 and double that number and add to your current BB.

 

[JohnE]

I should have listened to my HS math theachers when they told me I would need this stuff later in life! Thanks guys!