Bicycle Mechanics - bottom bracket thread direction.

Need to know which way the thread goes anticlockwise or clockwise got one side out but its in really tight and dont look like the shop greased it before they put it in.

I always have the same question, no matter how many times I take BB's off I never remember the direction. But I am going to suggest anticlockwise, because you pedal clockwise, so if the BB thread direction was clockwise, it seems like it would be easier for the BB to come loose. So I would try anticlockwise.

yeah but on the other side you pedal anticlockwise so do you think that one comes out the other way

If its English thread, you turn counter -pedalling.
If its French, counter-clockwise.

I can never remember either. That is why I have saved an old BB for reference. It saves me a lot of time and effort. BB and pedals are not something most people take off very often and it is easy to forget.

What kind of bike are you working on and how old is it?

If it is a BB with free bearings, then the left side bottom bracket bearing cups and lock ring should be normal standard threading - rightee tightee, lefty loosey. (Bear in mind MichaelW's correct info that French bikes CAN BE weird and opposite).

Also, it is the left side which is the removeable side. Don't spend energy, time, and tools trying to loosen the permanent side (right side).

Unless the mechanic who worked on the bike before you was an idiot, the BB parts are usually not put on too tight. They are usually put on just snug. Thus, if it seems you are putting a lot of torque to your tools, you are probably doing something wrong.


Be sure to use the right tools. Bottom Brackets use weird and specific tools. Try to substitute something else and you will do a lot of expensive damage.

Bottom brackets both tighten by rotating toward the rear of the bicycle.

Originally posted by Dirtgrinder
Bottom brackets both tighten by rotating toward the rear of the bicycle.

Dirtgrinder, you assume that both brackets are move-able.

Some bikes have the "sprocket side" cup fixed and it is not meant to be loosened or tightened. it is threaded and look adjustable, but in fact is fixed in place.

I have seen some destroyed by guys who "couldn't get the damned thing to budge!" Then they bring it to me to see if I could replace or fix the cracked cups.

Originally posted by mike


Dirtgrinder, you assume that both left and right bracket or cups are move-able.

Some bikes have the "sprocket side" cup fixed and it is not meant to be loosened or tightened. it is threaded and look adjustable, but in fact is fixed in place.

I have seen some destroyed by guys who "couldn't get the damned thing to budge!" Then they bring it to me to see if I could replace or fix the cracked cups.

Bottom bracket threads are NOT uniform:

English and french threaded , (normally 68mm wide) have right hand thread on the right hand of the bike, (fixed cup), left hand thread on the left of the bike adjustable cup.

Italian threaded, (normally 70 mmm wide) have right hand threads on BOTH sides of the bike.

NOTE:
If you ruin the threads on your english or french threaded bottom bracket you can save it by rethreading it with an Italian thread cutter!!! The Italian system uses slightly larger inside diameters. After rethreading to Italian just use Italian cups and an English spindle