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1995 XR100 rear hub bearing tollerance
Posted: Sat Jun 24, 2017 6:51 am
by ken.gaal82
Does anyone know what the limit for the rear wheel bearing bores? the manual does not say I purchased a set from boss bearing and both sides slide right in. So I don't know if the bore is out of limit or the bearings are too small. I measure the OD of the new big bearing 1.550 and the ID of the hub big bore at 1.550. The small bearing OD is 1.258 and the ID of the hub small bore at 1.257. So i'm at a loss, any help would be appreciated.
Re: 1995 XR100 rear hub bearing tollerance
Posted: Sat Jun 24, 2017 5:03 pm
by Aussiecrf230
I have never seen a bearing drop straight in except when hub is heated and bearing chilled. About .001 inch should be enough to hold it firmly. With the hub clean is there visible signs that the large bearing has been moving in the hub? It maybe spin marks or polishing where the bearing outer was moving. If it has all is not lost. By your measurements it is 'at size'. Hubs have been knurled in the past to provide a raised surface to reduce the inside diameter. There are also various bearing race locking compounds. Look at the hub as a whole for other damage, how are the sprocket holes and spoke holes. Is it a brake drum as well and is it worn. Maybe it is worth replacing with new hub.
If you have let the bearings get too bad the hubs will be flogged out. You should be able to go to internet to find out the bearing dimensions. I can't see how the small bearing goes in if it is large than the hub.
Re: 1995 XR100 rear hub bearing tollerance
Posted: Sun Jun 25, 2017 11:59 am
by ken.gaal82
I have never seen a bearing drop straight in except when hub is heated and bearing chilled. About .001 inch should be enough to hold it firmly. With the hub clean is there visible signs that the large bearing has been moving in the hub? It maybe spin marks or polishing where the bearing outer was moving. If it has all is not lost. By your measurements it is 'at size'. Hubs have been knurled in the past to provide a raised surface to reduce the inside diameter. There are also various bearing race locking compounds. Look at the hub as a whole for other damage, how are the sprocket holes and spoke holes. Is it a brake drum as well and is it worn. Maybe it is worth replacing with new hub.
If you have let the bearings get too bad the hubs will be flogged out. You should be able to go to internet to find out the bearing dimensions. I can't see how the small bearing goes in if it is large than the hub.
Aussie,
There is no evidence of the bearing spinning in the bore. I ordered some Loctite 648 and will knurl the bore before I install the new bearings. that should get me where I need to be. It sucks because I "rear-u-me-d" the bores were good when I drove out the old bearing and then had the hub powder coated so I'm kind of committed now. Plus I have a wheel shop waiting on me to send the hub so they can lace up a new wheel for me. maybe ill take some pictures and post up my results for others to see.
Ken
Re: 1995 XR100 rear hub bearing tollerance
Posted: Sun Jun 25, 2017 11:31 pm
by Aussiecrf230
Sound good Ken, everyone loves pictures. Make sure everything is well degreased before the loctite goes on. It probably had something on the old bearing if you had to tap it out. Good luck.