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My bloody cones keep coming loose on my rear wheel, it's a mavic 319 , shimano hub.
Every week in having to tighten them back up as the wheel is wobbly!
Is my wheel knackered??
Not wishing to teach you to suck eggs, but do you know how to tighten cones and then back them off against the locking nuts correctly? If the cones arent locked with back nuts properly they will undo.
http://sheldonbrown.com/cone-adjustment.html
Stoner- I thought I did, but I'll have a look at the link and see if I'm doing something wrong.
Thanks for the help
One thing I dont think Sheldon specifically describes is the locking technique. A method I use is to finger tighten the cones then finger tighten the locking nuts then hold the locking nut in place with a spanner, use a cone spanner on the cone flats and back it up against the lock nut. The finger tightness between the two should mean that the cone only turns 1/8th of a turn or so. Enough to leave the right amount of play in the bearings. If it's too much or too little, make adjustments to the original "finger tightening". Dont forget this technique is only required on the second cone, the first cone should be locked already with a locking nut and just pulled in to the bearing shell.
Is it both sides or the drive side? I found some loctite thread glue helped on my XT hubs (the drive side one would come loose every now and again).
Once they come loose and get worn I find that they never stay tight again. Not an expert but that's been my experience.
The axle could have a slight bend in it.
If it has been done up tight enough, and that is pretty bloomin' tight and its still coming loose I'd be looking for a bent axle or a misaligned frame
If you lock them correctly, as Stoner describes, then nothing will cause them to come loose.
Neither wear, misaligned frame or 'bent' axles will affect them IF done correctly 😆
Thanks for all the help/info
It's definately not a misaligned frame as I run another set of wheels for the trails. The problem rear wheel is my commuting one so used everyday. I'll strip it down when I get home and see if I can see anything untoward,
If not I'll try cone tightening procedure.
If all else fails it looks like a new wheel
monkeychild - Member
Is it both sides or the drive side? I found some loctite thread glue helped on my XT hubs (the drive side one would come loose every now and again).
OP doesn't say which shimano hubs but despite many many years of correctly adjusting cup and cone hubs I had to Loctite a rear XT one after repeatedly loosening - not sure year if relevant but probably 3years ago? at time seemed to be a common problem
On a related problem: my rear wheel is adjusted so there is a slight amount of play with the QR done up loosely, yet it doesn't run very freely. There is no visible damage to the cones, and it feels smooth when turned by hand. Bearings and grease are new. Any thoughts on what the problem might be? Hub is a Shimano 6500 Ultegra.
ransos rubber labyrinth seals causing drag ?
I had this on the rear wheel of a bmx a few years ago. I would tighten and lock them up so they ran perfect then a few miles later they would be loose again.
In the end I stripped the hub down and found that the axle threads were deformed.
I replaced the axle and all was well.
Andy
ransos rubber labyrinth seals causing drag ?
I did wonder if I'd incorrectly re-fitted a seal somewhere, though from memory there's only one rubber O-ring on each side. I may try re-assembling the whole thing without the seals and see what happens.
Edited to add: On the Shimano diagram ( http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/FH/EV-FH-6500-1679_v1_m56577569830611839.pdf) the left and right hand seals have different part numbers, so I assume they're different sizes. It's possible I swapped them over...
If all else fails it looks like a new wheel
By all means if you're feeling flush and want a bit of retail therapy, but you should be able to buy just a new axle/cone assembly. Often if Shimano, it can be cheaper to buy the hub cheaper from a discounter and take the bits out.
How would a misaligned frame cause a locknut to come loose, unless the locknut wasn't done up properly. Surely the frame is pretty much irrelevant in this discussion?