i have a centurion lemans, im not sure what year its from. can anyone tell me how to convert the old cup and cone bottom bracket to a cartridge? do i need to buy any extra parts to do that?

thanks in advance.

You basically just remove the old cups, and install the new cartridge. You don't need any other parts...just the proper tools, and make sure you get the right width spindle...

You can't convert it. It's a remove, toss and replace.

Also, check that your cranks are compatible with the bottom bracket spindle. I'd assume your current cranks are "square taper". Splined bottom brackets are common these days, and are not compatible with square taper.

the fixed cup over on the right hand side wont budge at all, do i need to remove that to put a splined bb in? any tips on getting it off?

thanks again.

It is reverse threaded. Make sure you are trying to turn it clockwise to remove it.

A lot of folks find it easiest to clamp the fixed cup flats in a bench vice, then turn the frame.