Bicycle Mechanics - Replacing Bottom Bracket

I'm going to be replacing the bottom bracket on my roadie and I was wondering if it will be as simple as I think it will be. I'm wicked-good with tools and mechanically apt.

Is there anything to this operation that will surprise me? (I know that I'll need a special tool to remove the BB.)

Reverse thread on one side, can't remember which side! Never can! I always end up with the old trial and error method!


From www.parktool.com/repair_help/FAQcartdg.shtml website, "For non-drive side, remove by turning clockwise. For drive side-turn counter-clockwise."

L8R

Okay, it is just like pedals so it will not loosen itself during operation.

:beer:

I'm assuming a few things, but typically chain side is left hand thread.

Just doing the math in my head based on typical rotation of the crankshaft, I'm thinking that the chain-side will be standard right-hand thread and the other side will be left-hand thread.

They should both tighten toward the front, loosen towards the back. I always think of the way the cranks turn; you would want them to tighten that way, not loosen.

You probably know the formulas better than I do, however, right pedal, right thread, right cup left thread. I promise. (Unless you have Italian or Swiss bb which would be REALLY strange.) Nothing to worry about.

of course, if you turn the bike over, then the left side is left threaded....etc.

On my old road bike, both BB threads loosen towards the "front".

I have trouble remembering that one out too.

Good Luck!

Actually, the bb threads and pedal threads are OPPOSITE. I have no idea why. When I put in my first bb a few months ago I must have tried for 5 minutes to put the first side in, even reversing trying the other retainer. When I finally tried inserting the drive side retainer counter-clockwise, ie toward the rear with the bike upright, it went right in. Like others I had assumed both sides would tighten "forward". Go figure. Of course, I also have an old Bianchi with Italian threading, both sides "right to tight". Keeps me on my toes I guess.

FatBomber, you are right. Assuming you are using sealed cartridge bearing bb, all you need is the appropriate installation tool. Then just follow the instructions. With different threading on each side you can't get it backwards unless you are very creative. Be careful with the Shimano splined bb tool. The splines aren't that deep so you have to concentrate a little on keeping the tool seated and avoid slipping and chewing up the splines. Not a big danger, just need to pay attention. And although it needs to be good and tight, you don't have to use extreme force. The plastic retainers do NOT have to be screwed in flush 1-2 mm of reveal is not unusual. If you try to force them, they will crack.
FWIW,
Raymond

Thanks a bunch, folks!

Time to get me hands dirty tonight.

:beer:

In addition to the BB tool, you will need one to remove the cranks.

The Right side BB is Left hand thread. (Chainring side)

The Left side pedal is Left hand thread.

Just confirming what others have said.