Good afternoon internet hive mind. A friend has inherited a bike that has a wobbly bit somewhere inside the bottom bracket. I'm taking bits from old bikes to cannibalise into a new one to make it rideable and to be honest the whole thing is a great learning experience for me anyway, but I've hit a problem. In the past I've removed the bottom bracket with the correct tools, then to remove the bit that contains the ball bearings I just use an adjustable wrench to unscrew it. On this bike it isn't nice and hexagonal shaped to allow a wrench to grip properly, it keeps sliding off. It looks like some kind of unique tool is needed, can anyone assist me in removing this so I can replace the bottom bracket? I've attached a picture of the offending bit.

Buy tools* or have a Bike Shop remove it.

We figure things like that Out there . sometimes it takes 2 of us..

* what do you own?

a big adjustable wrench , and figuring out how to not have it slip off does involve some creativity.

Thanks, I figured I'd need a specialist tool, but I haven't any idea what tool it would be. Any suggestions?

You can still use a plain ol' 12 inch crescent wrench - just needs to be decent quality. You may need some penetrating oil first. One can fashion a way to hold the wrench in place using the bolt for the spindle and some washers/spacers. There is a specialized tool, but it makes no sense to purchase one for a type of BB that is obsolete. Alternatively, take to a bike co-op or bike shop for assistance.

Also, a wobbly bottom bracket may only need adjustment, and you often can't just transfer one bottom bracket to another - they have different dimensions, even different tapers on the spindle. https://www.sheldonbrown.com/bbtaper.html

Doesn't look like any 'specialist tool' apart from an open end or large adjustable wrench to engage the flats on
the cup. Problem is not much to engage versus the torque needed. If the axle is hollow I would try some
all-thread through the axle hole and enough of a stack of "washers' of a size or drilled out to go over the
axle and hold the wrench in place. If the axle is removable from the other side, then you could use a larger
diameter all-thread. Alternatively use the crank fixing bolt and a stack of 'washers' to do same.

Thanks all. Useful information here. Very much appreciated

Good Luck trying to find Metric 'all thread' in The US. IDK if there is any made in europe , I'm not there.

more likely; take your crank bolts to an Auto Parts store and get some that are longer
and maybe a Big Flat washer .

Bike frame held in a repair stand also Helps A Lot!

Appears from your profile you are from the UK (Country of Residence GB?), further supported by the license plate and the non-U.S. spelling. Here's a search for bike co-ops/kitchens over there:
https://www.google.com/search?q=grea...op+OR+kitchen) Also the Sheldonbrown.com site that I linked to above is an outstanding source of info, along with parktool.com.

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...that's your adjustable cup, so if it's pretty well corroded in place, you will doubtless learn a great deal from this repair.

Ask Yourself Is it worth it, to buy one to use Once, for an Old Obsolete BB you will never re install?

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...I have one already. I use it often enough that it's worth having. I assume the OP can figure out whether he wants to buy one or not. I just answer the questions as best I can, man. I'm not gonna tell people what they should and should not buy.

We have the road forum for that.

https://www.fastenal.com/products/fasteners/rods-studs/threaded-rods;jsessionid=17CB1DE83F0A9BC8045982E9878E3178.fcomjvm02?r=~|categoryl1:%22600000%20Fasteners%22|~ %20~|categoryl2:%22600169%20Rods%209and%20Studs%22|~%20~|categoryl3:%22600173%20Threaded%20Rods%22|~ %20~|sattr01:^Metric$|~

If you don't have the special tool this is what you need. In place of lots of washers a large socket can make up much of it. The key is holding the tool solidly in place. Make sure you are turning the correct direction too.

Honestly even with the correct tool it's a good idea to use fasteners and washers to hold the tool in place if stuff is tight.

A pair of crescent wrenches, secured with a stack of washers or a short socket over the spindle, retained by the crank arm bolt.

Good luck with the fixed side.

I've also removed them with a hammer and punch, but it's not hard to deform the flats.

Use the right tool for the job, or take it to a shop with the right tool. When your wrong tool slips you can really screw up your back.

Which is exactly why Zinn invented the Vise Whip, and Pedro's marketed it and distributes it. There were just too many mechanics that had seriously injured themselves when a chain whip slipped.

I've often used a c-clamp to keep various pullers and wrenches from slipping off.
If it was me, that's probably where I'd start with this one too.


The nice thing about bracing against the crank bolt is that retaining force won't be affected by the turning of the cup.
With a c-clamp you need to remember to back the tension off as you turn.

Put it in a vise.

Mount the vise, get it in there tight, turn the frame.

The threaded hole in the spindle is M8x1.0 but, of course, so are the crank fixing bolts. The OP could use on of them to clamp a stack of washers over the adjustable wrench.

The fixed side on non-British bikes with that style adjustable cup is often a standard cup with two flats that can be removed with the proper tool or the Sheldon Brown tool. The Sheldon Brown tool can work on the British fixed cups with the raised section if the cup isn't too tight, but the raised section means less surface for the Sheldon Brown tool to grasp and sometimes this means you'll need the fixed cup tool from BikeSmithDesign:

I second the vise bit.

"Wobble" can come from many things. The bearing cups and/or bearings could be rusty or corroded. The adjustable cup (that's the side in your first pic) could have come loose. Which prompts my first question, to the "hive mind": isn't there supposed to be a lock ring on the adjustable cup? Or did you, OP, already remove it?

A second question: if the square crank wasn't tightened up properly in the first place, or the crank-arm securing bold (That screws into the axle) was loose or missing, the socket can loosen up and you end up getting a worn and distorted axle socket in the crank. If that happens, you need a new crank arm. Are the squar holes in your crank-arms still crisp, with no bell-mouthing?

But the most important question comes from your picture, where it looks like the bottom of the chain stay is rusted to the point where there's a hole in it. If so, THIS FRAME IS NOT SAFE. If so, and if the frame is a really fine one that is otherwise ok, it may be repairable. I suspect that its not a hand-lugged Colnago made with a Columbus steel frameset, my suspicion is that your frame is toast.

That's an adjustable cup, though.

The fixed side has flats out on the edges as opposed to in the center, and it should be in there pretty good.

It can be removed with a pipe wrench and the proper application of force, but the result is often gouges in paint and cup.

I improvised those enough times, but bought the tool to go back with a cartridge.

what are you seeing that we're not?

If you get the adjustable cup off and want to remove the fixed cup on the drive side Sheldon Brown has a greatt homemade tool that works really well.

Tool Tips--Bottom Bracket Cups

Quite inexpensive too.

Cheers

I see a collection of dirt and debris that needs to be cleaned. I see what you think is a hole, but I'm not sure.

In any case, it's a newer, somewhat cheap frame. I bet it's heavy-gauge steel. I doubt that area has rusted through.