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ThreeWrite
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Beverly, MA
Joined: 04/19/2016
Posts: 3

10miles into a ride this weekend I smelled something burning and noticed that the bike slowed faster than normal when I let off the throttle. I quickly pulled over and noticed a bunch of grease had spewed out of the rear hub (non-drive side) of my R65LS. The wheel was burning hot to the touch and looks like the rear brake was stuck lightly engaged. The photos attached show the area where the grease came out.

Any ideas on why the brake would have become stuck "lightly engaged" AND what I should look to replace/repair to prevent this form happening again? Also, does this appear to just be bearing grease?

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schrader7032
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VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
Posts: 6424
It looks mostly like bearing

It looks mostly like bearing grease. Have you tried to remove the rear wheel? The axle will have to come out to do that. Maybe have a look around and see what doesn't look right. If you're correct and the shoes are engaged, it might be difficult to get the wheel off. Is the rod that comes off the rear brake lever properly adjusted? Maybe something slipped at the end of the rod...if I remember correctly, there should be a wing nut of some kind that when turned clockwise will tighten the shoes onto the drum.

Another thing that comes to mind is that the bears have seized and have welded themselves to the axle. In which case, I don't think there's any recourse but to cut the axle off...I believe the wheel will be ruined.

Try to get things apart and go from there.

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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

ThreeWrite
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Beverly, MA
Joined: 04/19/2016
Posts: 3
Thanks!

schrader7032 wrote:

If you're correct and the shoes are engaged, it might be difficult to get the wheel off. Is the rod that comes off the rear brake lever properly adjusted? Maybe something slipped at the end of the rod...if I remember correctly, there should be a wing nut of some kind that when turned clockwise will tighten the shoes onto the drum.

Good catch Smile ... I should have added:
I loosened the wing nut and waited 10min... then tightened it back up and drove around for 30min. Brakes functioned normally, no heat buildup, no apparent issues resurfaced.

It's making me less worried that you didn't immediately say something like "OMG you're leaking spline lube!" Smile

mark_weiss
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Arizona
Joined: 11/17/2013
Posts: 171
Something caused the rear hub

Something caused the rear hub to get so hot that the bearing bore pressurized and hot grease forced the seal(s) to displace. You probably should investigate. Don't forget that there is an inner seal that may have be forced from its bore, just as the outer seal has done.

Why would things overheat? The brake could have been adjusted with insufficient clearance and one or both shoes began rubbing. Proper adjustment remedies this problem. It is possible, but not probable, that the brake compound may have overheated and glazed and that the brake drum surface has warped.

One or both wheel bearings could have failed. This produces localized heating and generally, some noise too. Remove the wheel, install a spacer onto the axle so that you can replace the nut and washer to preload the bearings, and check that the wheel turns smoothly and noiselessly. The axle should be able to rotate by hand with only minimal resistance. To perform a rough check with the wheel in place, raise the rear wheel and grasp at the top and bottom. Rocking the wheel side to side should not produce any movement independent of the final drive. Rotate the wheel and try in a few orientations.

Low lube level in the drive housing will allow the final drive parts to overheat. This will result in the housing being very hot, not so much the wheel. You can verify the lube level by removing the fill plug and taking a look.

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Mark
qualitycycleservice.com

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