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View Full Version : cup/cone hub bearing adjustment: "just right" or "slightly loose"?


wallymann
03-22-2012, 11:34 AM
ive always tried to adjust mine so that they felt perfect in your hands.

but i've heard some recommend adjusting them "slightly loose" in your hands, so that when clamped by a skewer in the dropouts the compression brings them into something approaching perfect adjustment.

for grins, ive tried this in the shop and it does seem to happen, but in practice i always adjust to perfect feel in the hands -- i guess by extension of the alternative technique my bearings end up slightly tight when a wheel is clamped.

what's the consensus among folks that still use hubs with cup-n-cone bearings?

chismog
03-22-2012, 11:40 AM
Slightly loose. I too used to adjust to perfect feel, until I tried slightly loose and found the QRs removed any play when tight. Have to think perfect feel would mean too tight when the wheel was installed, thus shortening the life of the system. That said, I didn't actually wear stuff out by adjusting to perfect feel.

jds108
03-22-2012, 11:42 AM
Slightly loose. Find some big washers to mimic the frame dropouts, clamp down the QR as you would when mounting the wheel and see how easily the axle turns.

Mark McM
03-22-2012, 12:46 PM
Slightly loose. Find some big washers to mimic the frame dropouts, clamp down the QR as you would when mounting the wheel and see how easily the axle turns.

This observation leads to a common method to ensure the correct bearing pre-load - make the bearing adjustment with the QR compressing the axle.

Some hubs make this easy to do. For example, the lockring on a Campagnolo hub does not press against the dropout when the wheel is isntalled, so you can adjust the lock ring with the wheel installed and the QR tightened down.

On a 'traditional' hub where the knurled lockrings seats against the drop-outs, you need to use a simple jig to allow bearing adjustment. A simple jig can be made with the stack of big washers mentioned above. Put a stack of washers with the same total thickness as a drop out over the freehub end of the axle. Remove the springs from a QR skewer, and insert it into the axle from the freehub side (so the cam and lever end of the QR is against the stack of washers). Thread the QR nut onto the other end of the skewer and screw it down so that it presses against the non-freehub end of the axle when you close the lever. Adust the QR nut so that it requires the same amount of closing force as when installed in the frame - this will compress the axle the same amount as when the wheel is installed. Because there is nothing pressing agains the non-freehub locknut, you can now adjust the cone and locknot on the non-freehub side to the correct bearing pre-load.

oldpotatoe
03-23-2012, 08:04 AM
ive always tried to adjust mine so that they felt perfect in your hands.

but i've heard some recommend adjusting them "slightly loose" in your hands, so that when clamped by a skewer in the dropouts the compression brings them into something approaching perfect adjustment.

for grins, ive tried this in the shop and it does seem to happen, but in practice i always adjust to perfect feel in the hands -- i guess by extension of the alternative technique my bearings end up slightly tight when a wheel is clamped.

what's the consensus among folks that still use hubs with cup-n-cone bearings?


Wee, WEE loose.

Bob Loblaw
03-23-2012, 10:05 AM
I have always done it 'just right' in the hands. Never had a problem with bearing longevity (well, had a hub disintegrate 26 years ago, but it was French), and it seems setting it slightly loose would make it harder to true accurately.

BL

Wee, WEE loose.

giverdada
03-24-2012, 10:51 AM
i go very barely loose, making up for it when i preload the bearings with the quick release in the frame. i think sheldon brown had a bit on this, including a tool that achieved the action mentioned above - washers, pre-loading bearings while working on it, etc. i love cup and cone hubs. though i'm partial to the italian set, the first wheels i ever built were ma40 rims on shimano 600 hubs and they are still going, and still smooth.

martinrjensen
03-24-2012, 09:39 PM
Here's what I do. I have a couple of really thick washers that are basically the same thickness as the dropouts. I adjust the cones, then take the skewer with the washers and clamp as tight as I would when on the bike frame. then I check and readjust as necessary. Pretty easy to do and you can get it right every time this way.

Kontact
03-25-2012, 02:18 AM
Here's what I do. I have a couple of really thick washers that are basically the same thickness as the dropouts. I adjust the cones, then take the skewer with the washers and clamp as tight as I would when on the bike frame. then I check and readjust as necessary. Pretty easy to do and you can get it right every time this way.

Why is this easier than just putting it in the dropouts to check it? Sounds like a lot of extra work installing and removing the QR around these washers.


I've always found that if you set the hub a tiny bit loose, it will go away when you close the QR. So I don't remember ever doing anything after adjusting the hub, aside from confirming that the play vanished when I put the wheel on the bike.

I've also found that if you set the hub a hair too loose or too tight, you can force the adjustment either way by either tightening the lock nuts into each other, or loosening the cones away from each other. You don't need to start from scratch if you get the initial adjust close - just open the QR, stick two wrenches in there, twist and close it again.

CoKeithRecord
03-25-2012, 09:35 AM
Make your adjustment then install wheel and recheck after skewer is tight. OR, buy Kysruims - you adjust the bearings while the wheel is mounted.