February 23, 200917 yr How can I get the outer case of the old bearing out of the headstock? There is no 'edge' to knock against as the headstock tube flares out to accept the bearing, so the headstock tube is slightly smaller than the case. Is welding a piece of steel to the bearing case so that I can tap it out or pull it out the only way, or is there a special tool to do the job? Thanks, AMO
February 23, 200917 yr No tool that I know of. I've always managed to drift out most of those I've done, using something that is bent at the end to push it into the bearing and has a sharp edge which just about gets some purchase on the edge of the cage. It does depend on how tightly in they are held though. One set wouldn't budge so I had to use the weld technique you've already mentioned. Only other way I can think of, if welding isn't an option, is to grind through it and collapse it but that is a really tedious method with the risk of making a mess of the headstock too. Don't know whether you know already, but if yours still has the original ball type taper bearing, you can get normal taper rollers as a direct replacement - 30205 if my memory is any good (probably not) but check first...
February 23, 200917 yr Either weld a bit of steel across or weld a bead of weld around the inner part of the case and it will shrink when it cools leaving it a bit looser. I used to remove norton valve seats that way Dave
February 23, 200917 yr If your cutting it out B&Q do a dremel type kit which should make the job easier.
February 23, 200917 yr Author Hi Woody & Dave It looks like I'm going to have to go down the welding route... Frame still has ball type at the moment, I'm putting some taper rollers in, 30204 is the size 30204 = 47 o/d, 20 i/d 15.25 deep 30205 = 52 o/d, 25 i/d 16.25 deep Do you know if all the mar models used the same size? or have i got an odd size headstock?
February 23, 200917 yr No different sizes, they are all the same on the MAR, Gripper too. 30204 sounds right as I'm pretty certain (although same memory cells that tried to remember the number...) that the ID is 20mm on the Ossas. I may have an old box in the shed, if I'm in there later I'll check.
February 25, 200917 yr Find an old worn file 9 x 1 ins, hand grind a radius on the bottom close to the headstock inner diameter, grind the file bottom edge to form a nice sharp edge, grind /remove the file tang and insert the file into the headstock, the file ground edge will fit just enough to get a bite on the old race, put on a pair of safety glasses, then give the file drift a sharp tap and it will move. You can sharpen the end of the file if required, this is a usefull tool for other jobs too. Brian H
February 25, 200917 yr Drill two small holes at opposite side and underneath the shell. Use a good quality punch to drift the shell out. I personally wouldn't use this method on alloy frames.
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