Discussion in 'Bicycle Mechanics and Repairs' started by mickle, 6 Dec 2011.
What's the advantage in removing the tyre before trying to true a wheel?
I have some really bad wheels to deal with. They are steel chromed rims and are suffering from seized nipples and dings in the rims...
Any tips for freeing up the seized nipples, other than cutting them out? I've tried penetrating oil (plus gas) but that didn't seem to help.
Also any tips for straightening out the rims themselves?
Did you spin the wheels around so that the plus gas is forced into the nipple by centrifugal force?
Nope, I did it from the rim side - I'll try from the spoke side like you suggest, and spin it...
I have a few armchair observations, not having had to true a wheel for a large number of years, as I have only recently started cycling again:
1) If correcting a buckled wheel alternating spokes will have different tensions as the spoke tension will need to overcome the "set" that the wheel rim has acquired in the impact that caused the buckle. I suppose in theory if the spoke tension is loosened and tightened by the same amount in alternating spokes it should eliminate the possibility of also needing to correct an out of round condition as the resulting total tensile force in the area of the buckle will be unchanged. For a rim that is or would be perfectly true before being built into a wheel then identical spoke tensions should provide the best reliability for a wheel as the rim would be evenly braced. I have no idea what that tension would be but perhaps the gauge mentioned would assist in finding this.
2) Where the rear wheel drive side hub flange diameter is greater than the non-drive side the spoke tension will seem different when plucked due to the different length spokes (shorter spoke = higher note for same tension - can't remember the equation right now), but in fact will be virtually identical as the small difference in angle due to the larger hub flange and "dishing" (which will tend to cancel out) would I think be negligable.
3) Suggestion was made that spokes should be thicker on the drive side, but I would I have thought the stiffness of the hub in torsion would transmit the torque with negligable angular deflection to the non-drive side of the hub, so equal diameter spokes would be satisfactory.
...as I say just my thoughts.
I got my wheel trued yesterday at a LBS when I got home I noticed that the wheel is sort of egg shaped is this easy to fix myself or would I be better taking it back to the shop for fixing?
I think I'd take it back...if it's too far out and distorted they should replace the rim.....
Just ruined a reasonable wheel by using the pluck method.
When it went out too far I had to admit defeat. Wheel is now in the LBS and I am outside hoping he can sort it.
This is off my commuter so need it for Monday morning.
I think I had better do a bit more research before trying it again........
LBS on standby......
I've tried all sorts of gadgets and found them largely useless - unless the wheel is in perfect condition, which many aren't. Even the slightest damage or imperfection to a wheel can render a spoke completely useless. I've spent hours on some wheels only to keep coming back to the same spoke as the culprit, and most times needing to leave it 'loose' to get the wheel trued.
However, I do use sound in my preferred process. I only squeeze spokes to find the loosest of them, but I start off with tapping them in pairs, and adjusting accordingly so they both 'sound' the same. Then I move onto the fine tuning.
You are very clever.
Who? Me? :-)
I have never tried a bicycle wheel, but I have rebuilt a motorcycle wheel with new spokes and got it within 1mm of true, which was half the factory tolerance. The wheel stayed true for at least 10,000 miles of hard use. A couple of observations which might be of interest:
1. In an ideal world with perfect materials, all spokes on a true wheel would be of precisely the same tension and emit the same note when plucked. However, there will be variations in the composition of the rim and spokes which means that you will rarely or never achieve that. I aim for all spokes giving a similar sound (say within a perfect fourth, for the musicians among you) and would always tighten any that went plunk rather than ping until they were musical. After that, it's more important to get the rim true than to chase any theoretical perfection in the spoke tension.
2. If you are going to fit all new spokes or a new rim, take a photograph, or several, of the old wheel, showing the angles of the spokes, where they cross, how many they cross, and whether it is over or under. Once you get the wheel dismantled, you will never get it back again the same way unless you have a record of the layout, and a photo is the quickest way to do this.
As someone said up there ^^^ it's not difficult to get it nearly right, and very satisfying to do so, provided you are methodical. Frozen nipples are the main enemy (ooh, matron) and a good practice is to dip the thread of each spoke in engine oil before fitting, and then give each spoke a slight turn (say one-eighth) and back every season to keep them free. Always check the inside of the rim for protruding spokes and file back, as they can be very sharp.
its The method I prefer, it's just more intuitive to to turning clockwise to tighten. Unless it's just a very slight tweak I've always removed the tyre before dressing up as Steven Segal and truing a wheel.
Wheel truing is pretty much the only thing bike mechanics-wise that I haven't tried.. tempted to have a go next time, save a bit of cash from having the lbs do it for me..
It is very nice when you resurrect a wheel and get it running evenly. A simple pleasure, but very rewarding.
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