RD250 1973 bearing replacement help needed

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dfphoto
Posts: 1
Joined: Wed Jul 09, 2014 11:12 pm

RD250 1973 bearing replacement help needed

#1 Post by dfphoto » Wed Jul 09, 2014 11:40 pm

Hi group,

My old group is gone and I really need some help, I'm not a great mechanic and hardware doesn't quite make sense to me. That aside, I have an RD 250 and I took the rear wheel apart a year ago and now I forgot exactly where the bearings go, and I say this because I bought a set of allballs and two of the three bearings are the same size as the axle but the last one is larger. The spacer is larger than the two and smaller than the 3rd so I'm a little confused as to the order of the bearings and where the spacer belongs.

The spacer is the one that goes in the center of the wheel not the outer spacers that are obvious. I have some pictures and it seems like the larger opening bearing is also slightly larger and goes on the sprocket side hub and the other two smaller would go in the center of the rim.

My issue is the internal spacer if I put a bearing in the center of the rim and then the spacer I'm not understanding how it stays when the axle is not inserted. I don't have the stock bearings so I don't really recall how it was. I do have pics and perhaps one of you can help me?
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expat
Posts: 451
Joined: Thu Sep 16, 2010 12:26 am
Location: Massachusetts

Re: RD250 1973 bearing replacement help needed

#2 Post by expat » Thu Jul 10, 2014 7:24 am

You usually have 2 bearings the same size that go into each side of the wheel. The third larger bearing go's into the sprocket carrier (hub)
The long spacer (2" to 3") go's in between the bearings in the wheel itself. This prevents the bearings from having too much pressure when the axle is tightened. This spacer just floats inside the wheel hub but is prevented from dropping too far out of alignment with the bearings by an inner diameter in the actual hub of the wheel.
This is what the usual set up looks like... In the diagram, items 19 & 20 are the bearings and items 21 & 22 are dust seals. The long spacer is item 7.

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