remotelocal

Hey all, i'm woefully understocked on tools, and i have one major bottom bracket issue.

My old raleigh competition has an O.M.A.S BB, which i understand is very similar to the campagnolo of the time? it's not the titanium version, just the regular one (see https://www.classicrendezvous.com/Italy/OMAS.htm)

The BB is pretty much seized now, it was gritty for a while and after a hard few weeks on rain riding, the thing started to leach out rusty water at the spindle and now it's pretty much shot.

I need to remove the BB and replace it. I have no tools. what are the minimum tools required for this job? i need a shopping list. i can get a shimano sealed square taper to replace it for now and keep the O.M.A.S cranks and rings.

Just want to remove the BB, and clean it out, and then install a new BB. help an amateur please!

wrk101

You probably have bigger issues if rusty water has been leaching out the spindle. That is not a BB problem, that is a frame internal rust problem. (You probably also have a BB problem with what you described). If you are just going to do this job one time, it is probably cheaper to go to a shop and have them do it. Most tools start paying for themselves the second or third time you use them. Although I have a lot of tools, I still occasionally take bikes to my favorite LBS due to not having that one special tool. Realize this is probably the last time you will need a tool to fit the OMAS bb, since you are going Shimano (it will have a different tool for sure).

Riding with it gritty for a while is not a good idea, as you might have been doing damage to the bb. Now it is more likely that the cups and spindles are pitted, but they still might be OK. Cross your fingers on that one. New bearings and grease is cheap if that is all it needs.

A simple pin spanner will work on the adjustable side of that OMAS BB. No pic of the drive side, so I can't comment on that. Very likely tools will exceed the cost of removal, at least around here, I know they would.

Zaphod Beeblebrox 

A picture of your BB would be helpful here.

You'll need a crank puller to get the cranks off. Start with that.

Next You'll need a lockring wrench for the non-drive side to get the lockring off. Then your BB Cups should either have shallow holes in it that will require a Pin Spanner or if you're in a bit of luck the Cups will have a raised section in the middle with flat sides that you can get an Adjustible Wrench on. Remove the Non-Drive side cup using either a Pin Spanner or an Adjustable wrench then you can remove the BB spindle and Bearings from the Non-drive side. At this point you'll be left with the Drive-side (Fixed) cup in the frame which is usually not an easy task to remove. Give this a read https://www.sheldonbrown.com/tooltips/bbcups.html it will explain much more about how to remove the Fixed cup....I generally don't bother with that part because its such a PITA and opt to let the guys at the Local Bike Shop do it for me....only takes a quick second and they shouldn't charge ya more than a 10'er or a couple of beers.

To install the new Shimano BB you'll need a Shimano Cartridge BB tool.

Old Fat Guy

You need this:
https://www.parktool.com/products/det...=25&item=HCW-5

and this (or any pin spanner that fits, I like this one):
https://www.parktool.com/products/det...=25&item=SPA-6

You should not have to remove the fixed cup. Put a sleeve on the BB, that will help route the water away from the bearings and out the drain hole.

If the surface of the BB spindle is smooth, you will only need new bearings, not a new BB.

PB Blaster is your friend, use it!

remotelocal

thanks all. i think i may leave it to the LBS then... wrk101, you're right. these might be one time tools. i think i'll need to assess the internals of the frame before i go putting a new BB in too.

the BB shell doesn't have any drainage holes unfortunately, which is probably part of my woes. i hang the frame to drain water out the chain stays which have little drainage holes. I'm not riding the raleigh in bad weather any more, i'm stripping it right down and trying to preserve it as a dry day rider! i'd hate to kill it.

wrk101

Yes, the only reason to remove the fixed cup is if it is trashed out. And of course, it has to come out if you are going to install a cartridge bb.

Chombi

Not really worth getting a (possibly proprietary) tool for the OMAS, if you are switching it out for a different brand one with most likely, different tool requirements. Just have the LBS remove it for you and save yourself the dollars, skinned knuckles and frustration if it is indeed seized up on th BB shell. Water must be getting into the frame in large quantities to have it come out the spindle openings as you described. It's a good reason to have a small hole drilled at the bottom of your BB to let the water out. Also, a BB plastic spindle sleeve will keep most of the the errant water from reaching your spindle and bearings in the future.
Good luck on the BB change.

Chombi

Old Fat Guy

Chombi,

I can't believe you are telling someone not to buy generic tools that will work for a variety of applications.

Personally, I've never met a bike tool I didn't want. Usually two uses and it's paid for.

Bianchigirll 

if your not going to reinstall this BB simply take your bike to the shop and have it removed. thye have the correct tools, you don't have to buy something you may not have to use again and perhaps it will be quicker.

mazdaspeed

+1

ctjohna

For this bike i would suggest having the LBS do it for you. You will need the crank puller & BB tools. I've found that the 2nd need = tool purchase!