Hot hub — wheel bearings?

My 1978 Intramotor Gloria Scout was making some grinding noises intermittently while riding, usually at higher speed. When I stopped riding, the front wheel hub was very hot to the touch. Hottest in the center but also all the way out to the axel nuts. I'm guessing it's a wheel bearings issue, but could that cause the hub to get so hot?

When stationary, the wheel spins freely and does not make any unusual noise. Front brakes seem okay, maybe a little sticky but nothing major.

The wiki article on Repacking Cup and Cone Bearings is informative, but how do I know if I should replace my bearing cups, cones, and balls vs. just cleaning, re-greasing, and reassembling.

Re: Hot hub — wheel bearings?

A bad roller can get a flat spot,or chip, whatever that, under load, sometimes stops rolling and just drags along the race. It can start and stop doing what you’re describing.

With no weight on it, the wheel will still spin freely.

Only way to inspect it is to take it apart and degrease all the parts. Look at them really close and see if there’s any imperfections.

Personally, if I felt reasonably certain that my wheel bearing were doing anything wonky like that and I was taking it apart to look at it, I would just replace them.

Re: Hot hub — wheel bearings?

I don’t think a moped is capable of it, since they don’t weight much, but I had an old VW that started making intermittent bearing noises on the highway. After a min of me trying to figure out what the sound was, the right front wheel locked up and almost pulled me off the road.

The end result was the race welded onto the spindle. Could have been worse.

Re: Hot hub — wheel bearings?

Usually cause by brakes. That's why most hubs have fins in the outside. If your shoes are rubbing, they'll heat up. Problem is, if your shoes aren't rubbing a little, your brakes don't work.

A warm, or slightly hot hub after a ride is normal. Have you ever changed a car tire fresh off the road and the lugnuts are too hot to hold? Normal.

If you can cook bacon on your hub, NOT normal.

After a race I can spit on my hub and it'll sizzle. But as long as the brakes don't fade, it's ok.

But it's always a good idea to regularly clean, inspect, and regrease your wheels and check your brakes.

Re: Hot hub — wheel bearings?

I'd replace the bearings and insure that the brakes had clearance .

Re: Hot hub — wheel bearings?

If it was the brakes making a sound, it would be easy to test. Just apply them when you hear the sound and see if it goes away or changes.

Re: Hot hub — wheel bearings?

Repack and properly adjust the bearings, if they are undersize from wear they will not heat up from the wear unless some are out of round and are skidding not rolling. If you replace the balls you should replace the cones and outer race. Variance in the runout (badly adjusted bearing) can allow for brake contact as the wheel can cant slightly. Crappy adjustments can also lead to death wobble if you have your cycle tuned to exceed 50km/h (30mph).

When you reassemble, use a sharpie and 'paint' some stripes on the brake shoes. Disconnect the brake cable for the offending brake and take her up to speed then stop (obviously without using the 'maybe draggy brake') and see if there is any contact. If there is slight contact it gets worst at speed as the shoe heats up and expands and gives more contact. To correct draggy brakes you can give them more clearance within the drum by shaving a very little off the shoe where it contacts the cam. Verify by taking it out again for a goodly run without attaching the brake cable.

When you reattach the brake cable be wary of over adjusting and making the shoe slightly contact the drum again.

Re: Hot hub — wheel bearings?

for some reason my brain read this as

Hot tub - wheel bearings?

Re: Hot hub — wheel bearings?

> Simon King Wrote:

> -------------------------------------------------------

> When stationary, the wheel spins freely and does not make any unusual

> noise. Front brakes seem okay, maybe a little sticky but nothing major.

If they they are dragging, hanging up or not releasing then there's the problem. Check the brake linkage, shoe cam, return springs and cables for proper smooth action.

When you were spinning the wheels you said they spun smooth. Did you check for side to side movement or slop of the wheels by tugging on one side then the other? When wheel bearings fail they either make noise or get sloppy loose. Sometimes both.

Re: Hot hub — wheel bearings?

> Chris . Wrote:

> -------------------------------------------------------

> for some reason my brain read this as

>

> Hot tub - wheel bearings?

Wishful thinking ? LOL

Re: Hot hub — wheel bearings?

Thanks for all the thoughts on this issue. Upon closer inspection the wheel does not wobble when spinning, but does make some noise. I'm pretty confident the bearings need attention.

Why is it recommended to also replace the cups and cones when replacing bearings? Is it just the assumption that damaged/worn bearings will also mean your cups/cones are damaged/worn too? Replacement bearings are easy to come by, but finding the right cone nut and cup seems a little tricker. I assume I have a Grimeca hub given that it's an Italian bike. Going to have to take some measurements and look closely at Myon's wheels page to find the right components.

Re: Hot hub — wheel bearings?

The bearing balls are usually harder than the race cup and cone .

I've found that the cups and cones show wear before the balls , which may , in turn , cause the balls to go bad .

When you pull the balls out , clean them and roll each around in a smooth bowl .

You should be able to hear a slight tick like sound when one hits a flat spot .

I replace them anyway as they are pretty cheap at any decent hardware store .

If you can find sealed bearing replacements , it would be a big improvement .

Re: Hot hub — wheel bearings?

Pushrod Fifty /

They can be too tight also.

Re: Hot hub — wheel bearings?

> P D Wrote:

> -------------------------------------------------------

> I replace them anyway as they are pretty cheap at any decent hardware

> store .

>

> If you can find sealed bearing replacements , it would be a big

> improvement .

There should be some conversion info for sealed bearings for your bike. Good safety investment for your bike.

It is super bad news when a front wheel locks up.

Re: Hot hub — wheel bearings?

Michael Branscombe /

clean the bearing and grease it and see if it fixes it. clean and fresh grease can do wonders. never know what you'll find when you look in there through until you look at it.

Re: Hot hub — wheel bearings?

I really like the bearings in a bowl trick cuz you can not visibly inspect them for the wear.

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