Spoke Tension

cunnins4

I've had to rebuild a cheap piece o' crap wheel to replace one that's been damaged beyond repair (rim's gone, won't stay true) until I can afford to replace it, again.

I had to replace 6 spokes, then I trued it as best I can (it's about 1mm out at the absolute most, probably not even that). It seems to be doing just fine. Re-greased the axle too to make it roll better and it's working a charm although it's a little heavy.

The thing is, when i got the wheel originally, before the 6 spokes broke, I noticed that a lot of them were quite loose. you could easily move them about. The 6 that broke were loose ones, so when I put it back together I tightened a lot of them and now they're all quite tight, but theres still a bit of play in a few of them.

How tight should spokes be? All I have to compare to is the front wheel (32 hole compared to the 36 holes wheel I fixed, so higher tension would be expected?) and on the road bike, which has far less spokes again, so I'd expect higher tension in these?

I don't want to tighten the loose ones unnecessarily but don't want anymore broken spokes! I'm a bit more paranoid about this wheel because I trued it myself (first time ever truing a wheel) and because of the previous broken spokes.

So should they be REALLY tight like the road bike, or should there be a little play in them? Don't really have the money to take it to the LBS and also want to make sure I can true a wheel properly. When I have more money, I'll buy a decent rim and build up a wheel using the better hub and spokes I have already if I feel confident enough doing it.

Thanks

Straatvark

Simple answer for DIY projects - the tighter the better. There should not be "play".

There are methods to measure the tension, but for DIY, rather listen to the ping sound when picking them to get even tension distribution.

It is very, very unlikely that you will do damage with to much tension - the nippel will probably strip first, especially with aluminium ones..

Well done by attempting this yourself. It is very liberating to build your own wheels.

doozerie

I've always judged spoke tension by ear - according to this Sheldon Brown page on wheelbuilding the appropriate pitch is the musical note F# (he also links to this Check spoke tension by ear page). I used to just go with what sounded "right" based on testing some new similar wheels parts.

If you overtighten them, then you will almost certainly shorten the life of the rim significantly as the spokes will pull the rim apart over time (as mentioned in the Sheldon Brown page above, modern spokes and nipples are far less prone to stripping even at excessive levels of tension) - it'll start with fine cracks around the spoke holes in the rim and get worse from there. I had this happen to a couple of wheels that I built so I eventually bought myself a basic tensiometer. Trouble is though that for the tensiometer to be useful you really need access to the correct tension figures for your specific combination of hub, spokes, and rim, which can be hard to find. In practice I still rely heavily on the sound/note generated by pinging pairs of spokes.

DadaKopf

I might attempt this. Do you truly need a truing stand? A lad on Fixed Gear Gallery says you can get away using the bike and some yokes...

Lumen

It is perfectly possible for a set of spokes to get wrecked.

I had this on a hand built wheel with €3 aero spokes. It's not clear whether this was caused by incorrect tensioning, seized nipples or a faulty batch of spokes, but whatever, one went then then they all started going (and I wasn't even riding the wheel after the first spoke went).

Morals of the story: practice on something cheap, expensive != reliable.

flickerx

DadaKopf wrote: »

I might attempt this. Do you truly need a truing stand? A lad on Fixed Gear Gallery says you can get away using the bike and some yokes...

Last one I built, I just did it in the front forks of my bike, and used the brakes as a truing guide. I would say it was 95% perfect, no hops or bumps in the rim but very slight left/right glide. I was going cross-eyed from doing it too much and wasnt too bothered about it as it was a cheap self-build (which I subsequently sold :-)

I wouldnt do any yokes while building a wheel though. You need to be able to focus, rather than having your eyes rolling into the back of your head.

Har har.

doozerie

DadaKopf wrote: »

I might attempt this. Do you truly need a truing stand? A lad on Fixed Gear Gallery says you can get away using the bike and some yokes...

Yes, you can do it without a truing stand. Amongst the main benefits of the stand is the fact that it allows you to easily check whether the wheel is going out of round as well as check the side to side play. You can do this while the wheel is in the frame too, it's just more awkward and takes longer.

Basically, the stand makes the job faster and easier but it's certainly not essential. A good spoke key is essential though, but fortunately they are relatively cheap.