Bicycle Mechanics - BB - Service or replace?

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.




View Full Version : BB - Service or replace?


vulpes
06-27-07, 10:35 AM
I have an older adjustable type BB on a vintage frame. It's gettin a little more play in it than I like; clunks especially when spinning with less pressure on the cranks. I've looked at Sheldon's article on adjusting these and it sounds a bit tricky. I don't want to end up with ball bearings all over the place either. Am I being too apprehensive about my first BB adjustment, or should I just replace it with a modern sealed BB? I'm thinking of replacing the chain rings at the same time, too. The middle one is not quite straight and I would like a little bigger large one and a little smaller granny. Thanks in advance for your expert advice. :)


Benjamino
06-27-07, 11:07 AM
While my advice is not expert by any means, I can tell you that adjusting a BB is not rocket science. It requires patience (especially if you've never done it before) more than anything else. It may seem complicated due to the remarkable detail on Sheldon's site, but once the grease starts flowing it becomes quite simple. You can do it!!

TimJ
06-27-07, 11:50 AM
There's nothing to it. An adjustable bb was one of the first things I ever took apart. The only thing is having the proper tools. Instead of a pin spanner I got by with sticking needlenose pliers into the holes. Without a lockring wrench I got by with adjustable pipe pliers. You should get a crank-puller though, if you don't have one.

It's really no big deal and if there's no pitting on the axle there's no reason to replace the bb. Personally I don't even care if there is light pitting on the axle. If the bearings look sort of crummy I buy new bearings, but on an older bike with a standard-sized and threaded bb shell, if it looks decent I just clean it up and repack with plenty of fresh grease. The worst that can happen is one day it gets too sloppy to adjust away and you have to buy a new bb. In the mean time you can probably go for hundreds more miles on that old bb just cleaned and repacked.


waffenschmidt
06-27-07, 11:52 AM
I'm not advocating either approach, but when this subject comes up on the forum most people recommend replacing with a modern cartridge type bracket. They're fairly cheap, work well, last a long time and don't require adjustment.

The opposing argument is that cartridge BBs are a reflection of our disposable society. The counter-argument is that, since cartridges last longer than the normal interval between cup and cone BBs the cleaning, bearing replacement and regreasing required with the conventional BB is more wasteful.

Both will work and neither approach is all that complicated or difficult. Pick whatever makes you happy.

Gonzo Bob
06-27-07, 11:57 AM
If the races are in good shape, I'd just overhaul with new ball bearings. Otherwise replace with cartridge.

tellyho
06-27-07, 12:58 PM
I would overhaul - it's easy. Do some research before buying chainrings. You need to know if your front and rear derailleurs will handle the change.

HillRider
06-27-07, 01:22 PM
If you need new all three chainrings consider buying an entire new triple crank. Chainrings are usually priced so that a new crank complete with a set of rings is less expensive. A modern crank with it's ramped and enhanced chainrings will shift far better than the old "flat" chainrings. They are essential if you are using indexed shifting and a noticable benefit even with friction shifting.

If you decide on a new crank, it may (most often will) require a different bottom bracket and that solves your first problem too.

Adjusting a cup and cone bottom bracket isn't that tricky and the number of parts is not that many. Remove the lock ring and take out the adjustable cone. Take out (and replace) the bearing balls, clean it all thoroughly and reassemble. Don't remove the fixed cup unless inspection shows it's badly scored or pitted. If it is or the adjustable cup or spindle are, replace the whole thing.

As to the cartridge vs cup-and-cone debate. The c&c advocates decry the "disposable" cartridges but what do you do with a pitted or scored cup-an-cone bottom bracket? You dispose of it! They don't outlast a cartridge either and, in fact, require more time and maintenance to make them last even as long.

operator
06-27-07, 02:07 PM
Step 1: is to pull your current bb and inspect the races for pitting. If it's pitted forget about it and install new cart BB.

If it's not pitted, repack and away you go.

vulpes
06-27-07, 02:19 PM
Thank you all for your most helpful and informative responses. I've got a bead on it now. :)

vulpes
06-27-07, 04:38 PM
If you need new all three chainrings consider buying an entire new triple crank. Chainrings are usually priced so that a new crank complete with a set of rings is less expensive.

I must be missing something here. I did a web search on triple crank sets and triple chain ring sets and found that the chain rings were running about $60 to $90 whereas the complete crank sets were mostly well over $200.

HillRider
06-27-07, 04:39 PM
I must be missing something here. I did a web search on triple crank sets and triple chain ring sets and found that the chain rings were running about $60 to $90 whereas the complete crank sets were mostly well over $200.
Nashbar is selling an Ultegra triple crank complete for $90.