Bicycle Mechanics - Funny noise in my front hub

I've got a noise that I think is coming out of my front hub. It kind of sounds like a grinding. It happens even if I'm not pedaling. What could it be?

This could be very bad news!

Do not ride your bike until you resolve this problem.

Remove your wheel from the frame. Grab the axle with one hand and steady the wheel with the other. Use some muscle and see if there is any in/out play with the axle. There should not be any play.

If you know what you are doing, take your hub apart, check for grit, lubrication, and check condition of your bearings. If you can replace your bearings, do it.

Otherwise, bring it to your favorite bike wrench and have him check into it.

Originally posted by mike
1) This could be very bad news! Do not ride your bike until you resolve this problem.

2) Remove your wheel from the frame. Grab the axle with one hand and steady the wheel with the other. Use some muscle and see if there is any in/out play with the axle. There should not be any play.



1) Agreed. It could be a symptom of poor adjustment, grit/contamination, lubricant breakdown, or even a broken bearing.
2) With quick release, there should be a minute amount of play in the axle when the wheel is off the bike. Remounting the wheel and clamping the skewer will eliminate this play.

I had a funny noise. it turned out to be a leave was suck between the tyre and the brake. I removed the wheel and repacked the hub before I notice the leave...


K

My friend encountered an honest car mechanic under similar circumstances -- somehow, a leaf had gotten around the air filter of his old Mustang, making it run terribly. The mechanic in question quickly and inexpensively diagnosed and repaired the problem, earning a customer (and referrals) for several years thereafter.

:rolleyes: :rolleyes:

Richard , please set the scene for us ...... more details .... EG: wobbles ? , noises, grinding ?, metalic?, .. Hmm have you got a small piece of stone/grit/ something caught/stuck in the brake pad ?? always rubbing no matter what ?...on the rim ? please more details .....:confused:

Leaves that have glued themselves to the inside of the mudguard have caused me minor panics in this respect - well they did until earlier this week when the bracket holding the guard to the fork crown snapped... Now it's just a case of adjusting my new sportier looking guard so that it doesn't touch the wheel at the rear when the forks fully compress...

Richard

Ahh Haa ...... best leaf that one alone !!!!!:D

Originally posted by Buddy Hayden
Ahh Haa ...... best leaf that one alone !!!!!:D

What an aPOLLEN pun!

Originally posted by John E
quick release, there should be a minute amount of play in the axle when the wheel is off the bike. Remounting the wheel and clamping the skewer will eliminate this play.

I don't follow you on this one, John.

If his bearing cones are loose (assuming he doesn't have sealed bearing hubs), I'm thinking that no amount of skewer tension will fix the problem.

Originally posted by mike


I don't follow you on this one, John.

If his bearing cones are loose (assuming he doesn't have sealed bearing hubs), I'm thinking that no amount of skewer tension will fix the problem.

I've had some QR wheels where the last amount of freeplay is taken up on tightening the lever.

For my tuppence worth, sounds like grit in the bearing and you may get away with dismantling and cleaning/regreasing, unless the bearing cones are pitted

Originally posted by mike


I don't follow you on this one, John.

If his bearing cones are loose (assuming he doesn't have sealed bearing hubs), I'm thinking that no amount of skewer tension will fix the problem.

Mike,
John is not alone in this recommendation. I have read this guidance on cone adjustment somewhere, that is to leave a little play to be taken up when the QR is clamped down. I had the same thoughts. If the cone is adjusted and the locknut cinched up good and tight to LOCK it in place, how is the pressure from the flimsy little quick release lever going to compress the steel axle and or nuts enough to budge anything tighter? And why is this method suggested only for QR and not nutted hubs? Wouldn't the same reasoning apply? I adjust my cones where I think they need to be without regard to the QR. The wheel spins very nicely with no play and feels the same in or out of the QR as far as I can tell, ie not any tighter.
Regards,
Raymond

I have NEVER, NEVER had to allow play to accomodate QR tension. But then I use absolutely nothing but high end stuff. Come to think of it even the run of the mill Shimao, Suntour, Suze, etc. never dragged under QR tension. Once those locknuts are anchored against the cone there should be NO lateral movement of the cone assembly requiring some forgiveness to allow a QR to be tightened.

You guys are missing the crucial factor of axle compression. When a rear QR skewer is tightened sufficiently to hold the wheel in place, it squeezes the axle, bringing the cones minutely closer together. I have proven this to myself empirically -- adjust for zero slop, back off about 1/8 of a turn, secure locknuts, then remount the wheel and admire the perfect adjustment.

By the way, I am in good company in my recommendation:

http://www.sheldonbrown.com/cone-adjustment.html

I'm not arguing with you, John. I am trying to gain better knowledge and understanding. I find your comments compelling.

What do you suppose the deal is? Is the axle deflecting and causing the between bearing width to shorten?

I'm not arguing either. I'm just trying to envision the force required to compress steel. If only we knew a mechanical engineer who could weigh in on this.

I read "Old Smoothie" Brown's site. Technically, if the cone & locknut are locked against each other and if the axle spindle is of sound material there should be no compression from the QR no matter how much you overtighten it. The QR should strip out before bearing drag/lock. What typically happens is folks run the cone up to the bearings, back off a smidge and "then" lock the nut--- rather the two need to be locked together in opposing motions, using proper tools. They will not and cannot move inward to the bearings unless soft materials or wear is about to cause otherwise. I am well aware of bad cone adjs. dragging and forcing friction... been there many times myself. So while I don't dispute that it never happens, there are meny fine hubs that this worry is of no concern. Cheers!

Oh Ray , if only we did ..... ????, Ok , getting the cones adjusted perfectly then backing of 1/8 of a turn , (which is a lot !), might be ok If you believe that they are compressing ..But.....how do you get the QR torqued up the same every time ?? and who really knows what torque the QR needs to be to compress the cones just perfectly ?? NO way jose, you go right ahead and do it ..more power to ya !, I'm sticking with the method I know , and I don't have ANY vagueness about !!!!.

Well, as a mechanical engineer, as well as an amateur mechanic, I can't for the life of me see how this can be true. Perhaps it's because I'm rather anal about properly adjusting my hubs (I know exactly how tight they have to be before I bring the 2 cone wrenches together for the final tightening). I can say with some certainty that my axles don't shorten appreciably when tightened, but I've never actually pulled out my micrometer to check it, either. All I know is that my hubs turn freely, without play, before I install them, and that they are likewise free-turning and runout-free after the QR is tightened. And BTW, I have never brinneled a bearing race, either.
Perhaps on a thin-walled axle, there may be more compression, but I'd bet that buckling would happen before significan compression does. I may be wrong, but my engineering degree would suggest that I'm not.

Has anyone tried a variation on Sheldon's empirical test? (I admit I have not yet done so.) Set a tireless wheel in a fork or truing stand, adjust the bearings just to the point of zero play, release the heaviest part of the wheel (perhaps a reflector, or opposite the valve hole) at 9:00 or 3:00, and observe the pendulum oscillations. Repeat the experiment with the QR skewer clamped tightly.

I've got Shimano 105s for my front and rear hubs. I've only put about 3000 miles on the hubs. Today I noticed a bit of noise in the rear hub. It would suck if I needed new hubs. I just got new spokes, and I need to take my back tire to the LBS to have it retensioned.

Do hubs wear out? I took the bike in for a tune up after the first 1000 miles.

I bought a 300 dollar bike, and since then I've had about 500 dollars of upgrade done to it (most in the rear wheel). Cycling is NOT an inexpensive sport.
:mad:

Yes, hubs wear out. However it takes some abusive bahavior to do it. If you tear down the hubs and repack them every so often, they can last you tens of thousands of miles.

Originally posted by A F Baker
Cycling is NOT an inexpensive sport.
:mad:

Bicycling is only expensive if you make it expensive.

I am also a mechanical engineer by education and shortly to be by trade (hopefully, fingers crossed). I've also read this advice about QR hubs, in a couple of different places. I don't get why it works, or how you're supposed to guestimate how loose to leave things, but I'm not about to sneer at advice that seems to work just because I can't explain why!

Ellie

On bended knee I beg forgiveness of John E and Sheldon for having questioned them.

I have the Barnett Bicycle Institute manuals, which I find overly detailed and complicated for most purposes, preferring simpler manuals most of the time. However, they are great to have when I really get in over my head and when I remember to consult them, which I finally did on this issue. BBI describes a very detailed and, I might stress, EMPIRICAL process of cone adjustment for wheels with QR levers to allow just the right amount of play which is taken up by the closed QR lever. Basically the process is trial and error, starting with some play, close the lever, check for play, release lever, tighten cones, allowing some play, close the lever, check for play, etc., until there is slight play with QR open, no play when closed. BBI takes about 3 pages and a setup using a auxiliary spacers, nuts, vise bungee cord, labels etc. Their way is probably more accurate, but I doubt I'll go to the trouble. But it does seem to demonstrate that the QR does, in fact, apply enough pressure to make some kind of difference. I'm still not clear why the same wouldn't be true if using nuts instead of QR.
Humbly,
Rainman

Just my .02 (.05 Cdn) cents worth, I've certainly noticed a difference in how freely the wheel turns when for some reason I've adjusted the QR too tightly after replacing a wheel.

One reason why you should always take the time to check it before riding after doing some work on the bike.

Maybe I've got my QR too tight. I'll go out in a bit to loosen it.
If it eliminates the noise, I'll make sure to post it.

A.F., 3000 miles is a goodly amount of miles to go between repacking the hubs. Maybe it's time for a little service.;)

On this quick release hub adjustment topic. I do believe that Sheldon knows what he's talking about. I guess it all depends on how perfect you want to get your cone adjustment.

The hubs on my singlespeed are designed to have the bearings adjusted while on the bike. www.paulcomp.com
The front is a quick release and the rear is a bolt-on hub. It seems like a great idea. I just haven't been able to adjust them on the bike because I can't find 19mm cone wrench to do it with.
:mad:

Originally posted by A F Baker
Maybe I've got my QR too tight. I'll go out in a bit to loosen it.
If it eliminates the noise, I'll make sure to post it.

Out of paranoia, I keep my QR quills pretty tight. Losing your front wheel while riding could ruin your whole day ...

In a QR, the skewer in under tension, and the axle under compression, so a minute amount of slack is needed when the compression is released.
With track bolts, the axle is under tension, so there should be no slack.

You notice the difference between axles held in compression or tension, when an axle breaks. A QR will hold the axle in a (possibly) rideable position, whereas a nutted axle will fall out.

Without any elasiticity, you could not tighten threads.

Park tools concur with Sheldon on this.
http://www.parktool.com/repair_help/howfix_hub.shtml

'...it takes a community to raise' a NEWBIE.:) I've been around the block more than a few times on my bike, but when it comes to bicycle mechanical problems, I'm still a newbie.

My front hub QR was simply too tight. All problems are now resolved. Thanks for the help.

Originally posted by MichaelW
In a QR, the skewer in under tension, and the axle under compression, so a minute amount of slack is needed when the compression is released.
With track bolts, the axle is under tension, so there should be no slack.

You notice the difference between axles held in compression or tension, when an axle breaks. A QR will hold the axle in a (possibly) rideable position, whereas a nutted axle will fall out.

Without any elasiticity, you could not tighten threads.

Park tools concur with Sheldon on this.
http://www.parktool.com/repair_help/howfix_hub.shtml

Good analysis. Just one question:

Where were you 2 pages ago? ;)

We all agreed that the axle undergoes compression when the QR skewer is clamped. The issue was/is how far the axle compresses, i.e., whether the bearing cones move enough closer together to affect bearing adjustment. If the central shaft of a typical 126mm axle compresses by 0.1 percent, this has the same effect as advancing one of the bearing cone/locknut assemblies by a non-negligible 1/10 turn (since the thread pitch is 1mm).