I know I can take it apart & it should be printed on the btm bracket, but thought I'd have one ready so I can slap it back together after taking it apart. 1998 GT Timberline--square taper btm.bracket-anyone know the size--I think it is a 68 x 113, but I'm not positive. Doesn't sound real great after todays ride-may or may not last thru this season.
a) width of bottom bracket shell - most likely, it will either be 68 or 73mm.
b) length of spindle (take off the crank arms). This is a little tricky since you probably won't have direct access to the spindle ends with a ruler. If you have a pair of calipers, then you're good to go. If you only have a ruler, you can have someone hold straight edges against the end of the spindle and you can measure the distance between the two straight edges.