truthseeker14

I've repacked a fair number of hubs over the years, but this one has me stumped. It's a cheap hub with a solid (not quick release) axle from a Mongoose mountain bike. I adjust the cone nut until there is no play in the axle, use a cone wrench to hold the cone nut still while I tighten the thin lock nut against the cone nut. The other end of the axle is secure in an axle vise and does not move while I tighten the lock nut. After tightening and releasing the axle from the vise, I find that the axle is super tight, not just a little tight, but so tight that it can't move. What am I doing wrong?

smd4

I've never used an "axle vise."

Just loosen the cone a little more before you tighten the locknut. You're obviously tightening things too tight. When that happens, loosen things a bit.

Jeff Neese

Try holding the locknut stationary and then backing the cone up (loosening it) into the lock nut. The opposite of what you're doing now.

truthseeker14

An axle vise is made out of aluminum and holds the axle without damaging it. Yes obviously I'm tightening things too tight, but I don't see how. Both cone nuts are not moving, the axle is not moving, and the only thing that is moving is the lock nut which is against the cone nut being held by the cone wrench. I did end up loosening things a bit, but it bothers me that I don't know why things got too tight.

smd4

I know what an axle vise is. I just never needed to use one.

I'm not sure what the "problem" is, and not sure how to say this without sounding condescending, but it sounds like you were just tightening things too...um...tightly. You may not "see" the cones moving, but torquing things down basically caused everything to compress enough to tighten things too much.

cyccommute 

You might be letting the cone move a little bit when you tighten the lock nut. It doesn’t take much movement of the cone to make it too tight. Try using two cone wrenches…one on each side…and backing the cones off against each other. Don’t touch the locknuts, just the cones.

Bill Kapaun

IF the problem was happening when installing on the bike, I'd suspect the fork ends aren't parallel.
That doesn't sound like it's the case though.

Just install on the bike and using BOTH cone wrenches, try to back off the cones a bit.
This will get them super tight against the lock nuts, but should alleviate the problem.

icemilkcoffee 

This is a fundamental flaw for all cup and cone type adjustment schemes. You see, the cones have some in and out free play when it is on the axle. The more worn down the threads are, the more play there will be. When you screw in the cone against the ball bearings, it is pushing up against the balls and takes up all the slack in the outwards direction. Now when you screw the lock nut on there, the lock nut is going to push the cone inwards where there is plenty of freeplay on the threads. Now it pushes tight against the balls and ruins your adjustment.

maddog34

you are experiencing the tragedy of poor machining tolerances from the Chinese manufacturers... the threads are an extremely loose fit and the cones shift a LOT when the jam nut is torqued down. Loosen the cone a bit from "correct", THEN tighten the Cone and Jam nuts together,. Spin the wheel while only supporting the axle on your fingers, not Grasping it... does the axle spin on your fingers? does it feel "grabby"? it's still a bit snug.. Repeat as needed. Most have enough slop that the cones don't sit square with the axle, causing intermittent grabbiness...

getting too ham-fisted with the sloppy parts will have you replacing stripped out threads... they are THAT bad at times.

for the record, it's not the workers, it's Managers wanting a bonus and forcing workers to not check or adjust machines.
and the same thing happens in the USA.. See: "Firestone Tires delaminating on Ford Explorers".. A Manager pushed workers to use inferior rubber....

Mad Honk 

When all of these responses don't fix your problem please go back and count the number of balls in each side of the hub. An extra ball in either side will produce this issue. Smiles, MH

truthseeker14

Thanks for all the replies. It bothered me that I couldn't figure out why i was seeing what I was seeing. I did not consider the poorly machined threads. That makes sense. I like the idea of holding the lock nut and backing up the cone nut against the lock nut.

Bill Kapaun

It can get the adjustment dialed in after attaching the wheel, either QR or nutted.
Downside is you'll sometimes end up with super tight nuts and potential skinned knuckles the next time you service it.

IF the drop outs aren't parallel, the tighter you clamp/bolt the wheel, the more prone the axle is to bend. This can cause increased "tightness" to varying degrees. Sometimes, quite badly.

ClydeClydeson

The reason the bearing adjustment changes when you tighten the locknut is that, in every material, any load will cause some deformation. Even in a strong material like steel (the axle and the cone and the locknut), tightening the locknut against the cone causes deformation in the treads of the axle, the threads of the cone and nut, and in the bodies of the cone and the nut. his deformation is very small - probably in the hundredths of a millimeter, but that is enough to alter the bearing adjustment. The same ting happens with a hollow axle and QR skewer - if the bearings are 'perfectly' adjusted with zero play, tightening the quick release will actually squeeze the axle ever so slightly shorter (again, in the 1/100ths of a mm) and change the bearing adjustment.

truthseeker14

Yes. And this raises another question: how tight should the two nuts be tightened against each other? I've always tightened them "really" tight. But maybe a just a smidge beyond hand tight is all that's needed.

Bill Kapaun

Tight enough to hold the adjustment if you have to remove the wheel to patch a tire etc.
That's where you learn a bit from actual experience about a minimum amount needed.

Read 6 to 8-
https://www.parktool.com/en-us/blog/...and-adjustment

oldbobcat

No, "really tight" is correct, especially on the rear drive side.

Another trick I've learned is to hold the hub and cone stationary while threading the axle into the cone. Hold the cone against the ball bearings and turn the axle from underneath. Sometimes while threading the cone into the hub I'd managed to roll the balls out of the race inside the hub, causing it to bind.

davidad

I would snug the lock nut on the cone, then adjust the preload with one wrench on the loose side lock nut and one on the tight side cone. When the preload is set tighten the lock nut.