01-24-2010, 03:02 PM
I just got off the phone with my brother, who can't understand all the reverse threading on a bike, and which ones are which. So I thought I would take a moment and explain which threads are what and why. Hopefully this can help some beginners out there.
Bottom Brackets
----------------
Bottom Brackets are threaded normally on the non-drive (left) and threaded reverse on the drive side (right).
So removal would be always turning towards the front wheel. Counter clockwise on the left, and clockwise on the right.
Pedals
------
Pedals are threaded normally on the drive side (right) and threaded reverse on the non-drive side (left). This is exactly opposite of the bottom bracket.
Removal would be always turning towards the rear wheel. Clockwise on the left, and counter-clockwise on the right.
A good memory mnemonic for pedals to BACK OFF. Turn towards the BACK of the bike to get the pedals OFF.
The reason for reverse threading is due to a process called Precession. A good explanation can be found here: http://en.wikipedia.org/wiki/Precession_%28mechanical%29
Bottom Brackets
----------------
Bottom Brackets are threaded normally on the non-drive (left) and threaded reverse on the drive side (right).
So removal would be always turning towards the front wheel. Counter clockwise on the left, and clockwise on the right.
Pedals
------
Pedals are threaded normally on the drive side (right) and threaded reverse on the non-drive side (left). This is exactly opposite of the bottom bracket.
Removal would be always turning towards the rear wheel. Clockwise on the left, and counter-clockwise on the right.
A good memory mnemonic for pedals to BACK OFF. Turn towards the BACK of the bike to get the pedals OFF.
The reason for reverse threading is due to a process called Precession. A good explanation can be found here: http://en.wikipedia.org/wiki/Precession_%28mechanical%29
Dedicated scholar of bicycles