horizon wrote: ↑3 Apr 2022, 9:56pm
Quick update:
While in the process of procuring suitable bolts for the "friction" method, I found a bolt and nut off an old car seat. I set them up and actually got good purchase on the cup and was able to hammer and lever them tight. Something had to give first and it was the threads on the bolt.
I had already concluded that anything delicate enough to fit on the 3 mm flats was going to crumble quickly in the ongoing struggle. However I now expect that that will even apply to objects used in just applying friction to the cup. I am going to get some better bolts but have low expectations of the result. I've looked at the £30 cup spanners on the market but I just can't see how one would survive first contact with the hammer/lever or whatever was used to turn it.
A local cycling friend has told me that our local garage had put his cup flats in a massive adjustable spanner and the frame in a vice: it worked. I've put it on my list.
What concerns me is that although the tightness is no doubt aided and abetted by corrosion, AIUI the cup is tightened by the movement of the cranks. This is a good thing (it doesn't come loose) but it makes a nonsense AFAICS of torque wrenches, PlusGas and anti-seize: basically, the cup will tighten and exceptional force is required to remove it which the flats simply don't provide for, rust or no rust.
I'm going to give Plus Gas a better run for its money; I haven't tried heat yet. I'm going to carry on setting up better bolts and levers and I'm going to have a chat with man in the garage....
Remember, these things have worked very well for most of the time bicycles have existed, and this is the very first time you have worked on one.
The chances are it will come out easily, and even you will wonder what all the fuss is about; most of the stuff on the internet is written by people who haven't scraped a living working on bikes when these original loose ball brackets were the only option.
Neither bracket cup can precess; the fixed cup is tightened up to the flange, the adjustable cup sets the bearing preload and then is locked off by the lockring.
The easiest way to get it out is to take it to a traditional bike shop where they will have the traditional specialist tools, as in that thread linked by slowster......a huge BB fixed cup tool will get it out in minutes.
Remember the bearing cups are properly hard; harder than a Campag. fixed cup spanner, harder than vise jaws. It follows that any slippage will wear the tools, not the bracket cup.
If you want to get it out yourself and you don't have a bench vise, a properly big nut and bolt will do; something where you can strip the thread by hand force is only any good if the cup isn't tight. Car seat BELT nuts and bolts would be worth a look.
If you have access to a bench vise, don't clamp the frame in it!
Clamp the fixed cup flats in the vise, with a nut and bolt to stop it pulling out, and turn the frame.
A fixed cup spanner isn't any good for a really tight/corroded cup without a way of stopping the spanner slipping off. In the days of cottered cranks you had to wedge the spanner against the crank, cotterless cranks with a screwthread in the axle led to a tool which screwed into the thread and against the spanner
013 by
531colin, on Flickr
With the bearing out, clamp the spanner to the cup with a bolt
I will have mentioned this before, but you can simply crack these hard bearing cups out of the frame; cold chisel through the bracket shell onto the cup, cup resting on a block of wood, sharp crack with a hammer.
(One failure mode of these bearings was for a cup to crack...maybe due to excess preload)
Or it will come out with a big nut or big lever arc welded to the cup.....the heat shock helps!
