K2 / Proflex Riders Group
General => Tech Forum => Topic started by: pinion on December 16, 2006, 08:05:24 am
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Anyone know of a good method of removing the main pivot ball bearings from an Attack (or similar) frame? I'm a little reluctant to lay the frame on its side and start whacking it with a hammer, although that is how a friend of mine got the bearings out of his Razorback. Thanks.
FP
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you may want to PM Simon..he seems to be the resident guru........for mods at least. if there is a will there is a way. Shovelon is also mucho smart (IMHO)
good luck
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Anyone know of a good method of removing the main pivot ball bearings from an Attack (or similar) frame? I'm a little reluctant to lay the frame on its side and start whacking it with a hammer, although that is how a friend of mine got the bearings out of his Razorback. Thanks.
FP
They need replacing already? Which areas are they pressed into?
Terry
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I would avoid whacking them out with a hammer,
I would get a threaded rod that would go through the I/D of the bearings and once put through sticks
out about 6" each side,
then on one side, slide over a tube or socket with an O/D just
smaller then the bearings O/D,
on the other side I'd slide on a tube or socket with
an I/D of the tube just larger then the O/D of the
bearing,
then using suitable nuts and washers if required do up
the nuts thus pushing out one bearing,once out
remove sockets and threaded bar,
remove spacer that
was between the bearings,place the tube or socket
that fits into the frame tube into the frame and up against the other bearing,slide through the threaded bar and put the other socket onto the bar the otherside,use the nuts and washers again and press the other bearing out,
O/D=Outside diameter
I/D=Inside diameter.
its easier than it sounds.
you can reverse this to press new bearings back in,
ONLY press on the O/D not the inner race you can
damage the bearing.
Simon.
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Thanks Simon. Very clever. I have some time off between the holidays so I'll try to give that a shot if my family lets me.
To answer Terry's question, these are the bearings in the main pivot axle housing that's right above the bottom bracket. I got the frame used and the pivot seemed to work so I hadn't even bothered to check the bearings until my friend had to replace his Razorback's swingarm. He found out that his bearings were seized and the pivot axle had been moving by sliding on the frozen inner bearing races. I pulled my swingarm off and found that my bearings don't rotate either. The ones at the top of the seatstay where it connects to the swinglink are shot too.
Thanks again!
FP
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I gave it a try with mixed results. It worked like a charm getting the single bearings out of the housings at the top of the seatstay, but the bearing sets in the frame itself for the pivot axle and swing link are really stuck in there. I managed to snap the threaded rod as I was cranking on it trying to push the pivot bearings out. Since my remaining ideas are to either try to heat the housing with a torch to expand it a bit or use a big hammer, I think I'll just let the local bike shop have a crack at it.
FP
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Blimey they must be tight,
heat will help but that can spoil the paint job,
looking at this drawing (I don't know which year yours is ) http://k2bikes.com/tech_library/pdfs2/00/00attackframeassembly.pdf
it looks like you not only do you have to push out 4 bearings
but also the outer spacer as well,if that to is also an
interference fit no wonder its all so tight,
I suspect in the end an LBS would just beat it out
but at least it will be there problem.
Simon
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Mine's an '01, but the assembly is the same. I'll just let the bike shop do it. I assume they'll at least have done something like that before, and I'd feel like a jerk if I wreck it trying to save a few bucks. Instead I can focus on trying to make a disc adapter for my crosslink fork.
FP
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I replaced my pivot bearing a couple of years ago and now need to do it again. (Lots of sideways movement in the swingarm).
I was also about to start beating it up with a hammer, but instead took it round to a friend who is 'good at that kind of stuff'. He immediately set about it with the threaded bar technique described above.
The threaded bar was 8mm diameter, and the process was very noisy - gun-shot cracks every time the spanner was turned. But the bearings all came out, and replacement was a doddle.
HELP - as I said I need to replace the pivot again but my previous supplier in the UK has gone! Can anyone tell me where I can get a kit and how much it will set me back?
Thanks
Neil
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You should be able to get replacement bearings from any bearing supplier (someone like BSL,now called Brammer),
the old bearings should have a number stamped on the outer side edge,failing that take it to the bearing supplier and they will match it up,with a bit of luck you may end up with a better quality bearings than standard (try and get SKF).
Simon.
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Simon
I should have thought of that. I did the same when replacing my Hope bottom bracket bearings - cheaper from local supplier than the Hope ones from a bike shop.
My only reservation is that the other bits that also come with the kit might be worn.
They should be OK especially when only replaced a couple of years ago - and it's the bearings that take the strain.
(My previous swing arm kit was £30-40. Replacing the bearings only should be much less).
Neil
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bearing suppliers here ( bike spacific ) quite cheap
http://www.billys.co.uk/english/group.php?prod=bg-sealed
https://www.betd.co.uk/product_list.asp?CategoryID=155
should be what you need in there
all in the uk