square taper cartridge BB

[Kornphlake]

I'm rebuilding an old budget bike with the bits and pieces that I've upgraded over the years and for whatever reason never moved onto the old frame. I removed the old cup and cone bottom bracket and replaced it with a shimano square taper cartridge BB. I got the drive side in and tightened to where the flange is tight against the BB shell, but the non drive side cup seemed to be a little iffy. I tried tightening it down real good and the bb started to bind, this didn't seem right so I rummaged through my box of old parts to see if I could find a lockring that was supposed to go with the BB, but I couldn't find one. I ended up backing off the adjustable cup a little bit until it loosened up and then put the lock ring off of the old cup and cone BB on it. It's been so long since I worked on a cup and cone BB that I can't remember if I'm doing this right, should there be a lock ring in the non drive side cup?

[OGRipper]

I'm confused, when you say cartridge bb it sounds like one of the still popular shimano units where you basically have two pieces, the first being the whole axle and bearing assembly with the drive side (fixed) cup and the other being the non-drive cup. If that's what you've got the non-drive side is not really adjustable, and you don't need a lockring - you just first tighten the drive side (like you did), then tighten the non-drive up against the bb.

If you've got some unit that has sealed bearing cartridges but is otherwise like an older ball and cup design, you might actually have an adjustable cup and need a lockring...I remember Syncros used to make those pimp ti axle aluminum cup sealed bb's, for one example...

You should check to make sure there isn't a screw sticking into the bb from underneath from an under-bb cable guide. It might not be a problem with the older bb but still stick up enough to create problems with a cartridge bb.

[w00dy]

You shouldn't need that lockring on there, friction holds the secondary cup in place, but if it makes you feel better about not having the cup in all the way, it's not going to hurt anything.

[Kornphlake]

It's a more recent cartridge bb, it looks like an isis drive BB but it has a square taper spindle. I don't understand why the BB binds up when I tighten down the non drive side cup though. I guess I'll have to look a little deeper into the problem, maybe get out a flashlight and see if I can figure out why the BB binds, it's definately not supposed to do that right?

[-dustin]

my RF Sig XS binds a little. don't think you'll notice with the cranks on, though. i don't, at least.

[BigStonz]

Does your frame have a 68mm BB? Maybe you need a spacer if the actual BB is larger.