Question about dodgy wheel bearings

[uclown2002]

You guys lost me early on page 1!

 

[Yellow Saddle]

You guys lost me early on page 1!

Some light reading will get you up to speed.

http://www.amazon.co.uk/Analysis-Ro...1321&sr=8-2&keywords=rolling+element+analysis

 

[uclown2002]

Some light reading will get you up to speed.

http://www.amazon.co.uk/Analysis-Ro...1321&sr=8-2&keywords=rolling+element+analysis

I'll wait and see if it's offered in a sale!

 

[Yellow Saddle]

I'll wait and see if it's offered in a sale!

Promises, promises....

 

[Globalti]

Colin, I haven't read all the posts between your OP and this but... are you sure the noise isn't coming from the rear wheel? If they are Mavic wheels, could it be the infamous Mavic freehub squeal of death?

 

[ColinJ]

Colin, I haven't read all the posts between your OP and this but... are you sure the noise isn't coming from the rear wheel? If they are Mavic wheels, could it be the infamous Mavic freehub squeal of death?

Pointed out earlier by zacklaws!

I am becoming convinced that that is exactly what was going on. It is odd that I perceived the noise to be coming from the front of the bike, but I was in such a panic to stop that I wasn't really concentrating on the source. There was also a lot of distracting wind noise at the time.

I had never heard of the growl/squeal of death but I certainly have now after Googling for more information. I am astonished that such a loud noise and vibration can come from a hub that isn't actually broken!

I have just fettled the hub and it feels a lot better now. I haven't been out for a test ride yet but am fairly confident that the problem will have been sorted. (If it happens again despite the fettling, then I will be at a loss to explain what is happening!)

 

[ColinJ]

Oh, and thanks to everybody who replied to my questions!

 

[gbb]

No. That assumes that the correct adjustment just happens to be exactly the width of the nominal frame dropout or hub width. That would be a pure coincidence.

The correct adjustment will appear too loose when the wheel is out of the frame and exactly right with the wheel clamped in the frame.
What most people don't realize is the elasticity of steel causes the adjustment to change when the wheel is clamped. This only happens with QR because it applies pressure over the hub whereas nutted axle only strain the axle between the jamb nut and outside nut.

This is easily demonstrated. Put the bike on a stand and remove the wheel. Adjust the cone so that there is minuscule play at the bench. Now fit the wheel loosely (QR loosely closed) and demonstrate to yourself that there is play when the wheel is manipulated at the outer edge. Now open the QR nut, tighten it and start clamping. You'll notice the cone play disappearing. The trick is to have both variables come together at the right moment, when the QR is tight.

Once you have this setting right and then measure the OLD, you may or may not come to 130/135/100 mm, but that like I say will be a co-incidence.

Cones that are under and overtighted place too much strain on bearings and shorten their life dramatically.

We've obviously seriously disagreed on the other points (and will continue to do so )...but you're right re the above...its a lovely way to learn how to adjust QR hubs , you usually end up making at least a couple adjustments the first time to find the sweet spot...and those adjustments are good practice and practice gives confidence.
That's a conciliatory post YS ..I still disagree but that's normal, if we were all had the same point of view, it'd be boring.

 

[Yellow Saddle]

We've obviously seriously disagreed on the other points (and will continue to do so )...but you're right re the above...its a lovely way to learn how to adjust QR hubs , you usually end up making at least a couple adjustments the first time to find the sweet spot...and those adjustments are good practice and practice gives confidence.
That's a conciliatory post YS ..I still disagree but that's normal, if we were all had the same point of view, it'd be boring.

Shall I hang onto the "dick" insult or is this your way to say sorry?

 

[Smurfy]

No. That assumes that the correct adjustment just happens to be exactly the width of the nominal frame dropout or hub width. That would be a pure coincidence.

The correct adjustment will appear too loose when the wheel is out of the frame and exactly right with the wheel clamped in the frame.
What most people don't realize is the elasticity of steel causes the adjustment to change when the wheel is clamped. This only happens with QR because it applies pressure over the hub whereas nutted axle only strain the axle between the jamb nut and outside nut.

This is easily demonstrated. Put the bike on a stand and remove the wheel. Adjust the cone so that there is minuscule play at the bench. Now fit the wheel loosely (QR loosely closed) and demonstrate to yourself that there is play when the wheel is manipulated at the outer edge. Now open the QR nut, tighten it and start clamping. You'll notice the cone play disappearing. The trick is to have both variables come together at the right moment, when the QR is tight.

Once you have this setting right and then measure the OLD, you may or may not come to 130/135/100 mm, but that like I say will be a co-incidence.

Cones that are under and overtighted place too much strain on bearings and shorten their life dramatically.

Totally agree. But the point of the spacers is that it enables you to rotate the bearings and feel the adjustment while the bearings are under the compressive force of a QR skewer, but without putting the wheel in a frame. This works very well, because it's much easier to feel the bearing adjustment by rotating the spindle than by rotating the wheel. When you rotate the wheel, the leverage is so great you can't judge the adjustment so finely.

 

[zacklaws]

If it happens again Colin, just stop peddaling or back pedal slightly if your freewheeling and if it is the back wheel, the noise will change and that will confirm it. I find that once its happened to a free hub, its not long before it happens again even after giving it a thorough clean and lube. On Season of the Mists, I had hardly done 70 miles since lubing it before it went again on that ride. I think sometimes its caused not by the pawls becoming dry, but the white bush in the hub becoming worn as well.

But I've learnt my lesson, never buy Mavic wheels and to stick with Bontrager from now on as I always wear them out and have never had to service them apart for one set which had the old cup and cone system.

 

[ColinJ]

Oh, and there was me hoping that I could expect to get to next winter before having to look at it again!

I can't remember ever having to take a Campagnolo freehub to bits despite doing many thousands of miles on them. (Not that my memory can really be trusted these days ... )

 

[Yellow Saddle]

If it happens again Colin, just stop peddaling or back pedal slightly if your freewheeling and if it is the back wheel, the noise will change and that will confirm it. I find that once its happened to a free hub, its not long before it happens again even after giving it a thorough clean and lube. On Season of the Mists, I had hardly done 70 miles since lubing it before it went again on that ride. I think sometimes its caused not by the pawls becoming dry, but the white bush in the hub becoming worn as well.

But I've learnt my lesson, never buy Mavic wheels and to stick with Bontrager from now on as I always wear them out and have never had to service them apart for one set which had the old cup and cone system.

The noise comes from the rubber Z seal that runs against the vesconite bush. If it becomes dry, it makes that noise. the pawls don't make a sound, even when dry. Obviously, friendly clicking excluded. The seal needs a nice tenacious oil such as 90W gear oil.

 

[ColinJ]

The noise comes from the rubber Z seal that runs against the vesconite bush. If it becomes dry, it makes that noise. the pawls don't make a sound, even when dry. Obviously, friendly clicking excluded. The seal needs a nice tenacious oil such as 90W gear oil.

Which of course is the one part that I might not have lubed! I'll whip the freehub back off tomorrow and sort that out.

Vesconite - I'd never heard of that before. Interesting material!

Tenacious oil ... would chainsaw oil be TOO tenacious? I have lots of that sitting around doing nothing!

 

[Globalti]

I have Mavic wheels and I've read up on the infamous squeal of death. The freehub rotates on an alloy boss machined on the hub so lubrication is vital - Mavic have machined spiral oil grooves on the boss in an effort to improve the distribution of oil and they recommend that you use a lighter oil than engine oil, something like 3 in 1. The freehub also presses aginst a white plastic washer set in the hub, so when all this begins to wear (my boss is beginning to show signs of wear after about 8000 miles) the freehub will begin to gall on the hub and oscillate very fast, setting up the dry squealing noise. The nearest explanation I can offer is the horrible dry screech you get if you rotate a ground glass stopper in a chemical bottle or a decanter.

So Mavic owners need to strip the freehub off every six months, which is a simple job, then clean everything up and re-lube with light oil.