BB unit removal "top tips"

[David B]

Aargh! The BB (Shimano UNxx type as far as I know) on my Orbit America seems to be seized into the frame - not a big issue in some ways as it still runs smoothly, but I'd like to dismantle the frame for a repaint soon and fit a Hope titanium BB unit I've got lying around surplus. I've tried Plus-Gas poured down the seat tube and then left to soak overnight before applying a big adjustable spanner and my trusty Park splined tool without any joy. I don't want to do anything too brutal that might ruin the alignment of the frame itself (plus the splines on the cups are easily wrecked by one mistake too many); years ago I removed a Stronglight sealed unit by tapping out the axle and sawing the cups into segments with a hacksaw blade before knocking these away with a cold chisel, but the Shimano units seem rather more bomb-proof in construction so this may not be an option for me this time around. Suggestions most welcome.

Thanks in advance,
David

 

[Qubit]

You can use whole frame as a lever, mounting the removal tool in a vice and then rotating the frame around the tool rather than the other way round (if you get me).

 

[AR-CoolC]

Plus (and I know this sounds like teaching granny to suck eggs) make sure your turning it the right way.

 

[paininthe]

find a bolt and washer to hold the tool to the axle

 

[David B]

Will try the vice tip, I have access to one at work. Using a bolt/washer combo to keep the BB tool in place is an excellent idea, not heard of that before.

Thanks,
David

 

[bm0p700f]

In my shop I always fix the BB tool to the cups with a bolt and washer to stop the tools skipping (as it can even when the cups are not stuck) and rounding of the splines in the cup. I then use a 25.4" park socket over the park tool BB tool and long breaker bar is the cup is stuck. If the cup is not use a rachet as it speedup removal. It never fails. Remember to clean the threads and maybe chase them with a tap if there is rust in there. Using anti sieze on the re install may help removal in the future.

I think it easier than sticking the tool in vice and trying to balance the frame on the tool and turning the frame the opposite way you normanly would with the risk of the frame catching the bench, vice or something else and damaging the paint. Also frame are big so you need a clear alot of space.

 

[orbeas]

stuck BB

As you are having the frame re-painted, apply some heat to the outside of the b/bracket evenly allover. Becareful as you have filled it with plus-gas which will ignite. the hear will allow the bracket case to expand before the b/bracker unit, thereby breaking the seal between the 2, as it cools down spray WD 40/Plus gas onto the threads and it will run down between the 2. if its really seized you might have too do it over a coupleof days but it never fails !!!!