Unsticking UN72 cups - advice

[Woz]

Just to add, and what FC said, the NDS cup is a diameter loose fit with some sort of rubberised compound at the bottom to take up the loose fit. When factory new the compound is soft and acts more like a glue, and if NOS it will harden in place.

 

[markoc]

Will give it a 24hr soak, as the NDS cup isn't going anywhere fast. Not bothered about the DS one, I just need the NDS off to fit the flipping thing. Appreciate the advice given - will update tomorrow!

 

[was8v]

Er so its not in a bike?

Then whoever had it last just pushed the cup on by hand

so won't need much force to remove

just fit the tool to the loose cup in your hand and turn it a bit and pull

or like you say screw it the wrong way and just tap the axle a little, shouldn't take much force unless its been under the sea when not attched to a bike. infact once the tread starts biting it might come off.

 

[Woz]

A picture is worth a 1000 words. You get the idea. A few taps on the wood should be enough to break the bond.

 

[markoc]

Woz - thanks for your replies. Super helpful. Absolutely no chance of knocking it off easily, and I've tried a few less than delicate taps with the multi-purpose persuading tool and a wide spanner across the flanges. It is well and truly stuck. Have rested it in an adjustable spanner and soaked with WD40.

It's been fitted, but no idea how long it's been off a bike. Might resort to seeing if my father in law has a puller, as I'm not known for my patience in such matters.

 

[Woz]

Looks almost like NOS, doesn't seem to have any scratches on the cups.

I suppose the rubber compound only had about 20 years to set.

 

[was8v]

just screw it in the bb shell the wrong way and then grab the bb and pull with your hand

 

[Woz]

You must have some patience because you haven't sawed it off yet and bought a shitty plastic cup off Ebay.

 

[markoc]

OK so I got impatient.

Screwed the NDS into the BB shell as far as I could get it to protect the threads, and with an old crank bolt in to protect the axle. Then gave it a gentle tap from the other end with a hammer and drift. Nothing. Then a bit harder. Nothing.

Eventually I gave it a bit of a wallop. Nothing. To be fair I then had to hit it pretty bloody hard, but it's out. On retrieving it from the other side of the garage, where it had jettisoned itself (doh - should have thought about that) I have thankfully not damaged it, but there is lots of crusty dried gunk in there that had stuck it together - likely the rubberised stuff mentioned above. Cup unscrewed beautifully so no damage there - it must have been mounted to a garage queen as it really is pretty minty fresh.

Bearings still spin beautifully. So now to clean it up, and the build progress can continue.

Thanks everyone for the words of wisdom. Move along now please, nothing to see here...

 

[Woz]

FYI the rubberised gunk that hardens in time looks like this, the same compound as what is on the cup threads.