How do I measure a bottom bracket cartridge?

[GreenMantis]

I have a bike with a bad bottom bracket cartridge that I need to replace. But they come in different sizes, and I don't know how to measure the things.

 

[Frankenstein]

I have a bike with a bad bottom bracket cartridge that I need to replace. But they come in different sizes, and I don't know how to measure the things.

Well, pull it, measure the threads on the outside, that's the diameter. Tpi varies, but they have certain limited standards, measure a quarter inch on a caliper, count the threads between the prongs, multiply by 4 and look for a bracket with a similar diameter and about the same as the tpi you counted .

You might be able to just look at the model of the bracket if it's printed on it and Google the info, or just Google specs on the frame, if it's a popular brand you may get a hit.

 

[Stoneman]

I have a bike with a bad bottom bracket cartridge that I need to replace. But they come in different sizes, and I don't know how to measure the things.

just done this myself
can you post a pic?

measure the shaft end to end without the pedals than make sure your getting the right cartridge size for your bracket style
check the mounting for your crank it could have splines or normal square bolt on type and you should be good

 

[machanic]

Search (Sheldon Brown bottom bracket) the guy owns a bike shop of note and gives very clear accurate info on his site.

 

[FurryOnTheInside]

Search (Sheldon Brown bottom bracket) the guy owns a bike shop of note and gives very clear accurate info on his site.

https://en.m.wikipedia.org/wiki/Sheldon_Brown_(bicycle_mechanic)