Mystery Bottom Bracket

[Andy in Germany]

I'm sure there's a name for this, in fact I'm sure it's fairly common but I can't find it. What is this kind of BB called?

More importantly, what tools are needed to remove it?

 

[Paulus]

I must admit to not seeing one like that.
Is that the fixed cup on the drive side?

 

[Cycleops]

Looks like it held together with Allen screws, similar to this from the YST site. Can't see yours there so maybe a discontinued model? I assume you're already removed the spindle. Bearings are inboard?

 

[Ming the Merciless]

This is the tool, but you’ll likely want to find a cheaper version or borrow.

https://www.bikester.co.uk/campagnolo-ut-bb100-bottom-bracket-tool-M745544.html

 

[Andy in Germany]

Thanks for the help...

It's somewhat comforting that it really is obscure; I half expected thirty people to comment that everyone has a BB like that. This is the last bit on the bike; the cups and bearings are all gone; the bearing cages were so rusty they broke on removal. It's a nice Scott kids bike so if I can get this off I can replace the BB and have it working again. Unfortunately that's not going to be easy.

 

[classic33]

Looks like it held together with Allen screws, similar to this from the YST site. Can't see yours there so maybe a discontinued model? I assume you're already removed the spindle. Bearings are inboard?

View attachment 695891

That's a eccentric bottom bracket, stoker on a tandem, but I'd say you're correct about removing the spindles.

 

[Andy in Germany]

I'm plotting away here: I've been soaking the screw in WD40 and anything else I can find. I'm wondering what will happen if I put a 10mm bolt through and screw nuts down hard on both sides against the bracket, then turn the nut and try to to dislodge the bracket that way. I suspect this will result in the bolt slipping, because it relies on friction, but it's worth a try.

 

[classic33]

I'm plotting away here: I've been soaking the screw in WD40 and anything else I can find. I'm wondering what will happen if I put a 10mm bolt through and screw nuts down hard on both sides against the bracket, then turn the nut and try to to dislodge the bracket that way. I suspect this will result in the bolt slipping, because it relies on friction, but it's worth a try.

And if it's the same type as the eccentric bottom bracket, with each side connected to each other, how will trying to turn the bracket help?

Why not put a larger bolt through, tighten up, possibly removing some of the pressure on the threaded splines and then try turning them.

If your not interested in saving the bracket, why not drill the threaded splines out on one side.

 

[Andy in Germany]

And if it's the same type as the eccentric bottom bracket, with each side connected to each other, how will trying to turn the bracket help?

Why not put a larger bolt through, tighten up, possibly removing some of the pressure on the threaded splines and then try turning them.

If your not interested in saving the bracket, why not drill the threaded splines out on one side.

It's only on one side, in the same manner as a tightening collar on a normal BB, in fact it's a very similar shape to a cartridge BB tightening collar too; everything else is removed.

 

[Ian H]

Googling 'YST' turns up some interesting BBs, though none quite like that as far as I can see.

 

[Ajax Bay]

Think @Cycleops image is a red herring.

 

[I like Skol]

It's just a standard adjustable cup for a cup and axle bb. The seal is a nice touch. No need for a special tool to remove it. Just pop out the rubber seal and screw in a large nut & bolt (M12 should be about right from memory). If you tighten through the bb shell from the other side with a ratchet and extension bar it should just screw out.

 

[Mike Ayling]

That's a eccentric bottom bracket, stoker on a tandem, but I'd say you're correct about removing the spindles.

Disagree, looks perfectly round to me, not eccentric.

 

[Venod]

An adjustable peg spanner clamped in position with a plate and nut and bolt through the center hole is worth a try.

https://www.ebay.co.uk/itm/14359816...sORPDIPRbG&var=&widget_ver=artemis&media=COPY

 

[classic33]

Disagree, looks perfectly round to me, not eccentric.

The one in the picture posted by Cycleops, not the one Andy In Germany posted.