Bicycle Mechanics - Cone adjustment on rear hub...going badly
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01-01-11, 04:53 PM
Hello, On my Specialized Langster single-speed, the rear hub has some side-to-side play. Not extreme, but enough to make me want to correct it before it gets worse. From others here helping I've found Sheldon Brown's and Park Tools sites, just great stuff, but not quite as amateur or step-by-step as I need. Here's what happens:
1] Remove rear wheel, pull out each side rubber dirt barrier gasket
2] Loosen locknuts, at side where cone nut is available for adjustment by the conewrench, slightly tighten until the shaft wiggle/movement is gone...very slight turns...[hoping here I'm correct that only one side adjustment will do it]
3] when shaft turns freely with no wiggles, hold adjusted cone nut precisely in place with conewrench [felt great, no wiggle] tighten 17mm lock nut against it
4] reinstall rubber gaskets, replace wheel on bike
But now the wheel wiggles perhaps more on the bike than before!...Redo steps 1-4 several times with great sincerity and patience...Same result. ARRRGGHHH!!
Of course I'm first suspecting my 'technique', but, this is a used bike from CL bought recently, and the issue existed when I bought it, hell, could have been there for a year, who knows? Maybe the bearings could be shot and not even experienced hands of silk could perform a workable cone adjustment? Does someone see any problems with my adjustment approach, or an unknown [to me] issue? Thanks
01-01-11, 04:58 PM
you forgot to check the tightness of the cone/lock nut on the other side. you also check for play after the lock nut is tightened down. for freewheel hubs and front hubs i remove the freewheel. clamp the locknut in the vise. lock the cone against the clamped lock nut. adjust from the other side. takes 1-2 min. a vise really helps. also check park tools site on adjusting hubs, good tips in their if you dont have a vise. careful not the bend the drop outs
Before you pull your hair out, check that the axle isn't broken. Remove the QR skewer and see if you can move either end with respect to the other.
If the axle is OK I suspect that you're encountering a problem common to newbies. The axle turns easily, so you don't know if it's turning with the cone or the locknut. What happens is you tighten the cone, then when turning the locknut, the axle turns with it backing the cone out.
Most pros use an axle vise, but if you don't have one, you can gently clamp a vise-grip to the opposite end to hold the axle steady, or remove the springs from the skewer and tighten it into the axle to help hold it.
Once you keep the axle steady, you can tighten the cone, and bring the locknut up behind it without turning the axle. Don't forget that QR hubs shouldn't be adjusted too tight off the bike, because the pressure of the QR will compress them slightly when on the bike.
01-01-11, 05:58 PM
There are 2 possibilities: either you did not adjust it properly in the first place or it came loose with riding.
You can eliminate the second by first making sure that the cone is tight up against the locknut on both sides of the hub. Then make tightness adjustments on only one side.
For gauging the tightness adjustment, you do not have a quick release. You do not have to worry about pre-loading. The mounted wheel will have no forces pressing against the cone from the track nuts. That means you want to adjust the cone to riding tightness.
If you do not have a vise, you can lock the axle by mounting the wheel on the opposite side and outside the frame. This will hold the axle and permit you to use 2 hands: 1 for the cone and 1 for the locknut. It will also allow you to test for any play after you have tightened the cone, without placing the wheel back in its riding position. You also want to test tightness by looking for play at the rim rather than at the axle.
Also, you buy a complete new set of ball bearings and inspect the cups and cones. It's very little extra work/money; it will eliminate one variable.
01-01-11, 06:25 PM
Thanks Guys! Great stuff on this. The axle is OK, saw it moving both sides well in place. Love the 'mount wheel to the outside of the frame', thanks SBinNYC 'cause no jack here yet. I know I'm over-thinking this, because all your advice basically boil down to the same warnings/actions. Tomorrow I'll tackle it again; there's a good LBS near here in Green Valley, Bike and Hike that's open Sunday so I'll go by there also to check on buying new bearings. Sure to be a low cost deal, and I need to do be able to do these small issues, just a great way to better love a bike. We have a good coffee/crumpet shop near there also, Sertino's, where I was on the patio sipping a great bean when I noticed a Bianchi locked up nearby...Gawd what a work of art. Very few things are designed more elegantly than a fine simple bike. What enjoyment of form. Thanks again for all the great help, results tomorrow.
Nice attitude : )
Myself, I can't believe how many folks fail to appreciate the staggering elegance of our best invention...
The tip about cone adjustment with the wheel on the outside of the frame is a nice one.
But I developed a method that works a treat with the wheel in my lap. When the locknut is slightly tight against the cone, you can almost always get them to turn as one when you tighten just the locknut. You can do it with a cone wrench and just a single spanner or shifter if you ensure the other locknut is nice and tight against its cone first.
Once I have the loose cone pretty much where I want it, I tighten the locknut down by hand, ensuring the cone is a tad loose when the locknut gets to it, and lightly cinch them together with the tools. Then I feel for play on the spindle to get an idea how much it needs tightening, and use a spanner on the locknut to tighten both cone and locknut (here's where they should move as one) against a spanner on the tight locknut or maybe just the cone wrench on the tight cone, cause it's tighter than the friction on the other side.
I go a bit at a time, stopping to feel for play (you should be able to start within a turn or so of ideal). For a hub with wheelnuts, it's simple - just keep going until the play disappears. If you overshoot a tad, that's ideal, cause when you tighten the cone against the locknut it should back off a fraction. It's possible to fine-tune it slightly by either tightening with a spanner on each locknut, or loosening a bee's dick by further tightening either cone against its locknut (you could loosen further if you had two cone wrenches, undoing each cone into its locknut). For QR hubs, a tiny bit of play is required - I start with a fraction much, try it in the frame, and while it's there with the QR off just tighten both locknuts against each other a tad, then do up the QR and try again. This is possible cause there's a window where the locknuts are tight enough to keep their adjustment but loose enough to still turn as one with the cone.
With experience it becomes a breeze, after you develop a feel for it. Just make sure not to overtighten stuff.
When doing this adjustment on hubs I don't know the condition of, I'll pull the spindle and bearings and wipe off everything to check for pitting. 99% chance that if you see no pits in the cups or cones (a very slight and smooth groove is acceptable), you're good to go. I generally don't pay much attention to the balls cause IME you'll usually see damage to the cups and cones first.
Reassembling the hub is easy (here's a chance to centre the spindle if it sits to one side too). Just get some grease on the tip of your index finger and wipe it into the cups; you should be able to get a smooth layer in there up to a couple of mm deep, then you just plonk your balls in (with the spindle in the hub), and away you go.
01-02-11, 06:32 AM
I am curious about the hub. Is it cup and cone or radial bearings?
I find it is best to adjust the cones while still in the frame -or as some have said, mounted outside the frame on only one drop-out. This way you can check for "wiggle" easier by pulling at the rim rather than just pulling at the axle with the wheel on your lap. A wiggle that you can't feel just pulling at the axle can be felt when mounted to the frame when you are pulling with more leverage at the rim.
Another good way is to chuck the cone/locknut assy into your bench vise and then work on the other side of the axle/wheel. This allows the wheel to spin to check for over-tightness but you can't quite do as good a job with the wheel mounted horizontally as when the wheel is mounted vertically in the frame as the wheel will seek that one point where it is heaviest and you can tell right there if it is too tight. This is how I do it when I'm servicing the bearings as that is the way I re-assemble them -on the vise at the bench. But I still check it on the frame and sometimes a re-adjustment is needed if I missed the mark slightly when on the vise.
One thing to mention is WHY did the cone get loose in the first place. Was it not torqued correctly by the last mech to work on it or has there been bearing wear?
If it wasn't tightened correctly then make sure the far side is torqued to specs before trying to adjust the near side. If one end got loose then it is possible that the other end is ALSO loose. Check for a broken or cracked axle if it is a QR. Check for a bent axle regardless if it is QR or nutted.
If it was bearing wear that caused the cones to get loose then you need to SERVICE them with new grease and bearings. Just tightening them at this point will only be a temporary solution as the wear will only accelerate -very possibly putting the hub in jeopardy (one of the most expensive single parts on the bike considering labor to replace). Perhaps there was moisture and rust-pitting on the cones as well depending on how the bike was stored, most probably it needs new grease. If the grease is old or there is wear/pitting inside it will cause even greater wear and self-destructage. The hub itself is usually the last part to go and can often be saved by replacing the grease, bearings, and the cones (if necessary). But let it go just a little bit more and the hub races will pit/crack/gall and then it is junk.
01-02-11, 01:16 PM
Nailed it! Once the wheel is securely bolted to the outside of the fame, there's a stable base to tighten the opposing cone against...obviously. Strange how logic and practicality don't transfer easily from one task to another, and me a long time member of CBOA, Cheap Bastards of America. Now, if someone offered me a good wheel vise, I'd just say smugly, 'no thanks, I pin mine to the frame'...Great tip.
Kimmo - Mine isn't a QR type wheel, but thanks for the bearing replacement/check out description. Though the wheel seems fine now a hub tear down soon is in order to find out where I'm at on the bearing life. It's such a fine simple design it'd be a shame not to learn it.
davidad - From the drawings etc I've seen since this issue I'm calling it 'cup and cone'. Unless I'm wrong and someone picks it up.
Amesja - Yes, definitely better to check wiggle while the wheel is firmly mounted, I could see that starting out here. Horizontal over vertical, eh? It struck me that after reassembly, or even while 'outside frame mounted' I was guessing what was 'free spin' and was it acceptable, an error prone judgment probably. No idea really about the maintenance history on the bike, a CL deal, the PO was a young fellow, nothing not to like, and I asked very few questions assuming as usual I'd have many discoveries down the road. [Quote:'If it wasn't tightened correctly then make sure the far side is torqued to specs before trying to adjust the near side. If one end got loose then it is possible that the other end is ALSO loose. Check for a broken or cracked axle if it is a QR. Check for a bent axle regardless if it is QR or nutted.'] My assumption here was that if the one axle side is pinned to the frame I've got a solid base to tighten the other side against; are you saying the other side perhaps not torqued correctly may allow the other to loosen? Thanks
Amesja - Yes, definitely better to check wiggle while the wheel is firmly mounted
I disagree. IMO it's much easier to detect play with the wheel off than it is to detect a tight spindle when it's attached to something; that's the whole point of working on the wheel in my lap.
Apparently your fingertips are sensitive enough to detect a vibration with an amplitude of 1 nanometre; I don't find it difficult to detect the tiniest amount of play by firmly wiggling the spindle.
This applies more to solid axles than QR wheels due to the trial-and-error step of ensuring you have the maximum amount of play that will fully disappear when the QR's tightened.
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