Question...how much should a wheel flex...
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Go feel some other peoples wheel. It the only way you'll know.
wookiee":1bps2cbs said:
I infer from this that you had your wheel rebuilt with a new hub six months ago and now there is way too much flex in it. If so, I would suggest you take it back to the shop that rebuilt it for you and they should feel obliged to retension it FOC, since it's their poor workmanship that has caused the problem.wookiee":1bps2cbs said:
I think modern wheels tend to be built with lower tensions, as more emphasis is placed on impact absorption and less on motive forces - and also most wheels are disc wheels of course, so they don't need to be as true as a rim brake wheel. The trouble with that is that, unless the spokes are threadlocked, they can work loose over time. The only way for spokes to maintain their tension is either to have them tight in the first place, or to threadlock them. If you tell the shop to build them tight this time, you shouldn't have any further problem.
I see your problem. It would take me about half an hour, including re-checking the dishing, and I would expect a shop to be quicker than that.
On a rear wheel, the drive side spokes are tighter than the non-drive side (I think this is due to the asymmetric dishing). If you grip two spokes a couple of inches above where they cross, you should be able to squeeze the non drive side ones together by say 5mm or a bit more without applying too much force (depending on how strong you are of course). On the drive side, they should be quite tight, maybe a mm or two of movement in each spoke.
As I said above, modern factory wheels tend to have a bit more flex than that and it's supposed to be ok, but if you've got a lot more then yours must be a fair bit too loose. As I say if they're too loose, they'll just work a bit looser every time you ride them, and your rim will be taking all the impact forces which won't do it any good at all.
On a rear wheel, the drive side spokes are tighter than the non-drive side (I think this is due to the asymmetric dishing). If you grip two spokes a couple of inches above where they cross, you should be able to squeeze the non drive side ones together by say 5mm or a bit more without applying too much force (depending on how strong you are of course). On the drive side, they should be quite tight, maybe a mm or two of movement in each spoke.
As I said above, modern factory wheels tend to have a bit more flex than that and it's supposed to be ok, but if you've got a lot more then yours must be a fair bit too loose. As I say if they're too loose, they'll just work a bit looser every time you ride them, and your rim will be taking all the impact forces which won't do it any good at all.
Anthony":3kzornzn said:
Ah ok the tension varies around most of the wheel...guessing they have just worked loose as they have seen probably around 500-600 off road miles at least since they were put on my bike...I was thinking of giving all of the spokes a half turn as the rim runs true hoping that it might just stop so much flex...
That may well be worth trying, although if the tensions are all very different then it's a bit odd that the wheel is still true. It can be the case with a used rim though that the rim is no longer perfectly true in itself, so you need to build the wheel with some differences in tension in order to compensate for the imperfections in the rim.
However if the imperfections are such that the only way you can true the wheel is to have some spokes with too little tension to stay put, then maybe the rim needs to be discarded. That's especially true with a rear wheel, as the non drive side doesn't have much tension anyway. It's easier to compensate for imperfections on a front because you can build it super-stiff so that even the spokes with the least tension still have enough. That's not to discourage you though, just a possibility that's all.
The first thing I would do is to tighten each of the spokes that is really loose and see whether that stops the wheel being true (it may well not do, as a really loose spoke basically isn't doing anything at the moment). Then when you've got them a bit more equal, try tightening every spoke by the same amount. You're not doing any harm anyway, the bike shop can still fix it even if you make it worse.
However if the imperfections are such that the only way you can true the wheel is to have some spokes with too little tension to stay put, then maybe the rim needs to be discarded. That's especially true with a rear wheel, as the non drive side doesn't have much tension anyway. It's easier to compensate for imperfections on a front because you can build it super-stiff so that even the spokes with the least tension still have enough. That's not to discourage you though, just a possibility that's all.
The first thing I would do is to tighten each of the spokes that is really loose and see whether that stops the wheel being true (it may well not do, as a really loose spoke basically isn't doing anything at the moment). Then when you've got them a bit more equal, try tightening every spoke by the same amount. You're not doing any harm anyway, the bike shop can still fix it even if you make it worse.
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