Might be a dumb question, but this is the same bottom bracket I have on my 1987 specialized comp mtb.
Is this a 73mm or 120 mm bottom bracket?
Trying to source a new one and was looking at this: https://www.performancebike.com/shimano-deore-xt-bbmt801-bottom-bracket-black-bsa-68-73mm-ibbmt801b/p1567421?gad_source=1&gclid=Cj0KCQiA1Km7BhC9ARIsAFZfEIsK0UL4078GUZTTieZav0nQ-7yt_BirSEiQYEqpT6G8uzG-IkZMAqYaAj3TEALw_wcB
by 1kbeeler
3 Comments
73×120
73 bottom bracket shell width. 120 overall spindle length.
If you go with the BB you have linked, you will need a new crankset. That is a hollow tech BB you have linked. What you currently have is a Square Tapered BB.
To avoid changing the crank, you will need a Square Taper 73mmx120mm BB. I believe it is JIS, but i could be wrong. You can get a slightly longer spindle if it makes it easier to find (+1-2.5mm)
[Here is a 73×122.5 that can be ordered in the US](https://www.performancebike.com/shimano-un300-square-taper-english-bottom-bracket-silver-bsa-73mm-122.5mm-ebbun300c22b/p1220537?v=1218256)