dwengo

I'm renovating an old frame, I've removed the old bottom bracket but on one side there is a sort of... cap thing that I can't seem to get off, how would I go about getting it off, are any special tools required?


The right hand side, with the 'cap' thing on (I don't know why the camera focused on the brush in the background....)


Even the cat is confused


The other side

mixteup

That's the drive-side or "fixed" cup - You can make a homemade tool that works really well - Never failed me :
Tool Tips--Bottom Bracket Cups

Caution - It's possibly left hand thread

dwengo

That's perfect, I googled stuck fixed cup and can see that its a common problem, thanks for the tip will give it a tried tonight

Andrew R Stewart 

The "cap thing" is the RH BB bearing cup. It is very tightly secured into the shell and is often called the "fixed" cup to indicate it's not changing it's position after install. These can be a struggle to remove if the right tools are not available.

First thing is to determine the cup's threading direction so you know which way to turn it to loosen/remove it. By using the LH cup one can measure that and assume that the RH cup is also of the LH's spec standard. By looking into the shell carefully one might see the RH shell's threads and thus their direction.

Next is the tooling. While I have used bench vices and huge adjustable wrenches held onto the cup/shell with a through bolt/washers using the correct BB Fixed Cup Wrench makes things much easier to set up. Since the amount of force that will likely be needed to loosen the fixed cup is very large any tool slippage will mean greater injury.

This, like some headset work, is better done by a shop if good results are wanted. Their stock of tools and prior experience can make what can be a knuckle busting and dent prone procedure (if done at home) into a safe and damage free one. Andy.

Kovkov

You can also consider leaving it in place if it's still in good shape.

dwengo

This is a good idea, I've cleaned down the rest of the frame now, and kind of assumed that If I want to fit a new BB in I would need to remove the fixed cup. Is that not the case?

cyccommute 

Yup. You need a special tool to get it off. It's the worst tool ever made for a bike and the worst idea ever put on a bike...and there have been some real stinkers to compete with it! The tool will slip off and you will bash your knuckles. The cup is also on there tight so the tool will slip many times and you'll bash your knuckles many times. The thread is also a left hand thread so it righty loosey.

You can save your knuckles a but by using something like this to hold the wrench in place

2015-03-14 11.28.26 by Stuart Black, on Flickr
2015-03-14 11.21.32 by Stuart Black, on Flickr

The parts are from old bike parts...an solid hub axle, axle nuts, the top of a kickstand and a lock ring. You can substitute a large fender washer for the lockring. Some clever monkey at my co-op improved the tool since the picture was taken by using a right hand cup screwed into the frame on the other side to keep the tool centered. It's still a horrible tool to use but at least you don't bash knuckles.

You might just want to take it to a shop and pay someone to take it off.

I would also suggest not putting it back on. Get a cartridge bearing bottom bracket and don't look back.

dwengo

Thanks for the info, I realise I've got a lot more research to put in before going any further. I didn't realise there were so many different bottom bracket types and not all of them will match the frame either

noglider 

But seriously consider not taking it out unless you're going to put a new one in. And if you do decide to take it out, heed the above advice and know that it is probably reverse-threaded.

One way that sometimes works for me is to clamp the cup in a bench vise and use the frame as the lever.

Kovkov

Depends on how much of it You need/want to change. If all the parts are fine fresh grease will do it (and new balls since they are cheap). Of all old bikes i overhauled this far not one had bad cups. I often had to change the spindle because of pitting.

andrewclaus

Once you determine it needs to be removed, you determine the correct thread pitch (RH or LH), you get the right tool, and it still doesn't come off with reasonable force...use a heat gun on the shell, and rap with a mallet on the handle of the tool.

As said above, unless you have a professional tool, assume the tool will slip and plan for your knuckles to fly somewhere safe.

Homebrew01

90-ish % of fixed cups are left hand thread, so "Clock-wise" to remove.
I've also had good luck usung cyccocommute's suggestion of clamping the tool in place for more difficult removals.

davidad

Griping the cup flats with a vice and using the frame as the lever usually works.

DannoXYZ 

More like 99.9%

Homebrew01

Yeah, 90% was low. ... 99.8453%

Gresp15C

I've had some success giving the fixed cup tool a few gentle taps with a hammer. Clamping the tool in place, as @cyccommute shows, helps. Penetrating oil helps. Presence of rust suggests that the cup might be in there pretty good.

If you can clean the cup while it's in place, and see that it's not pitted, then it doesn't really have to come out. You could still put in a couple drops of penetrating oil, and then leave it for next time.

Reeses

Use a breaker bar on the end of the flat headset wrench of the correct size, hold the wrench on with your palm. Slowly break it free

Its a regular forward thread so back it out towards the back of the bike to loosen it

DannoXYZ 

Also squirt PB-blaster from inside onto threads. And outside as well.

That stuff is magical! I've sprayed it on stuck seatposts and left it overnight. Found seatpost had unlocked and slid all way down into seat-tube by morning!

Crankycrank

Lots of good info here but I'm surprised that no one has mentioned that cats are useless at removing BB's. They also don't care if you mangle your knuckles when the wrench slips. I love cats. They're nice to have around but not much help with bike maintenance.

ksryder

Looks kind of aloof, too. Must be a Cat 1

southpier

so … as far as determining direction, would I be correct thinking left side is reverse thread, and right side is conventional ?

in other words:

left side = clockwise to LOOSEN

right side = counter - clockwise to LOOSEN

that way, pedaling would be a tightening force for both sides.

(1984 Peugeot P-17 in question)

thanks
ps: I tried the cup in the vise method but was reluctant to try too hard for lack of directional knowledge!

southpier

OOPS: I just read the link in this post (Thank You mixteup) so maybe my above questions are superfluous !

noglider 

Nope. Pedals are like that, where the left pedal (for your left foot) is reverse threaded. Bottom bracket cups have reverse threads in the fixed cup, the drive-side cup, the cup nearer your right foot.

southpier

got it; thank you.

JohnDThompson 

To be fair, there are far better tools for dealing with a stubborn fixed cup, e.g.:



But they're not cheap. And really, if there's nothing wrong with the fixed cup, there's no compelling reason to remove it.