Hubs & Ergo trainer

Colin Marshall said:

Hi,

I have a Minoura Ergo 10 Inter Rim trainer. Since using it, the hub on my rear wheel have become
very rough. Pulled them apart to discover they are pitted. The hubs are a year old and are Campag
Chorus. The front hub is fine. I assume its has been caused by the trainer. Has anyone else had
this problem? Is it caused by me tightening the trainer too tight against the hub?

Thanks

Hi,

I doubt that the QR skewer could be clamped so hard by the trainer that it could damage bearings by
its own accord. Now - having the cones adjusted perfectly with the wheel out of frame may result in
them being too tight once the *QR* is tightened [and that's an earlier thread], but the additional
forces from the trainer's clamping would be trivially low.

Pitted bearing races to me indicates a corrosion problem, not disintegration due to overload by
tight cones. Have you ridden repeatedly in the wet without cleaning out and repacking the bearings?
Around late autumn (and in early spring) there may also be a lot of salt on the roads, depending on
where on the planet you cycle. Then you bring the cycle indoors, start training, and notice suddenly
that the hubs are bad. Hard to determine without knowing how often you pull your hubs apart . . .

But you also raise another interesting question, which probably has nothing to do with your problem
- would the balls in the hub start carving a slightly different path in the races when a trainer is
used? Consider that the flywheel pressing against the tyre will do so at a force much *less* than
what the road usually exerts. The weight of the cycle and rider is supported to a greater degree by
the axle, and much less by the wheel bearings. But this would not cause pitting, either - just a
slightly wider track in the races, if that at all.

/Robert

Robert Brown said:

Pitted bearing races to me indicates a corrosion problem, not disintegration due to overload by
tight cones.

most of the hubs i've seen with pitting are due to spalling, not corrosion. this includes campy
hubs. spalling is a function of bearing load, so i'd say over-tight cones is far more likely.

rule of thumb - if the grease is cloudy & rust colored, it's likely to be corrosion. if the grease
is uncloudy but grayish and even slightly sparkly under *strong* light, it's spalling.

jb

Colin Marshall said:

I have a Minoura Ergo 10 Inter Rim trainer. Since using it, the hub on my rear wheel have become
very rough. Pulled them apart to discover they are pitted. The hubs are a year old and are Campag
Chorus. The front hub is fine. I assume its has been caused by the trainer. Has anyone else had
this problem? Is it caused by me tightening the trainer too tight against the hub?

If they are pitted, do you have a "drip path" from you to the hub? Sweat can do nasty things.

-=Dave=-

Colin Marshall said:

I have a Minoura Ergo 10 Inter Rim trainer. Since using it, the hub on my rear wheel have become
very rough. Pulled them apart to discover they are pitted. The hubs are a year old and are Campag
Chorus. The front hub is fine. I assume its has been caused by the trainer. Has anyone else had
this problem? Is it caused by me tightening the trainer too tight against the hub?

Probably not.

A trainer can't press as hard across the axle as your skewer because its frame isn't rigid enough.

Trainers need only be tight enough to keep the bike from rocking. Overtightening will bow the
trainer's frame on a Minoura, Tacx, Silencer or CycleOps before any other effect.
--
Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971

Thanks, no I don't ride much in the rain, no direct line for the sweat to get to the hubs. I had the
rear wheel off about 6 months ago and a mechanic put a spacer in the hub, he said the cluster was
rubbing against the frame and since then the wheel has been rebuilt in November and the spacer
removed then. At that time, the mechanic did not say there was any problem. May need a new mechanic,
or even better learn to do it myself. Just seems strange its only the rear hub and not the front.

A Muzi <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Colin Marshall said:

I have a Minoura Ergo 10 Inter Rim trainer. Since using it, the hub on my rear wheel have become
very rough. Pulled them apart to discover they are pitted. The hubs are a year old and are
Campag Chorus. The front hub is fine. I assume its has been caused by the trainer. Has anyone
else had this problem? Is it caused by me tightening the trainer too tight against the hub?

Probably not.

A trainer can't press as hard across the axle as your skewer because its frame isn't rigid enough.

Trainers need only be tight enough to keep the bike from rocking. Overtightening will bow the
trainer's frame on a Minoura, Tacx, Silencer or CycleOps before any other effect.