Bicycle Mechanics - can you stand ANOTHER spoke question?

I can get my wheels to be kinda strait.

that is, if the rim hits the brake pads I can get it so it spins freely.
I do this by slowly tightening the spokes on the opposite side from where it touchs the brake pads.

I can't get it to spin without any wobble but as long as it doesn't hit the break pads I'm fine w/ that. the wheels will never stay strait with the kind of riding I like to do, they just need to roll.


with that said, I'd like to talk about spoke tension. sometimes I will get my rim so it's fairly strait but there will be a spoke or two that seem to have very little tension.

If I tighten them up, I will loose the trueness of the wheel.
should I loosen all the spokes up and re-true it to keep good spoke tension or could it be that my rim is really bent and there is no way that the spokes will all have the same tension unless I replace the rim?

Hope I made that somewhat clear.....

thanks!

I am no expert but I have watched a few wheel builders. If you wheel is warped and hitting the brake for example they will normally adjust 3 or 4 spokes on the opposing side. When you adjust only one this will put too much pressure on one spoke where in reality there is probably a few spokes out of align.

Like I said I am no expert this is just an observation. This is one of those jobs I will leave to the experts until I get a truing stand.

Originally posted by pnj
or could it be that my rim is really bent and there is no way that the spokes will all have the same tension unless I replace the rim?
That is a good insight into wheels :) If the rim doesn't want to be straight, then trying to convince it using spoke tension is ordinarily going to leave the spoke tension uneven, unless the rim itself is unbent first (not easy to do right). C'est la vie... just keep working on it, and you'll get better and better at the convincing part :)

You mentioned that you tightened spokes that pull the rim in the direction it needs to go. If possible, also loosen the ones on the other side in that area, unless they're already so loose that they're not really doing anything already. This helps keep your wheel from going out-of-round, for one thing.

If this trend continues, get the LBS to rebuild your wheel with some DT or Wheelsmith 14-gauge spokes and a beefier rim, when you can afford to. :)

yea, i didn't want to get into too much detail ( I probably should have...)

but I do tighten about 3 or 4 spokes or whatever on the one side to pull the rim over. how much for each spoke depends on how close it comes to hitting the brake pad.

as I mentioned, there are NO wheels that will stand up to some abuse. Now i'm not riding off cliffs but I am hard on wheels. so they are gonna get a little out of true.

but what do to about the spokes that have very little tension once the wheel is fairly true?

I don't think my wheels are really bent, i just got this bike a week ago and have only jumped curbs and stuff. but you know how crappy stock wheels can be. they don't allways have the correct spoke tension....

thanks guys!

If you can make your rim run true only by mismatching spoke tension, the rim is definitely warped. The wheel may be serviceable, but it will never be as reliable or as truable as one built from a straight rim. This is why most custom wheelbuilders insist on using new rims and spokes.

While that statement is true (no wheel standing up to abuse) there are some that are better at it. The Mavic 321D 36 hole is very strong and light 680g for its strength. Breaking a spoke or two won't actually affect its truness leaving it straight. If you are having a lot of problems with broken spokes look into this rim or something comparable. (Ryno lites are not in the same league)

A wheelbuilder at your service...

Loose spokes here and there and a straight wheel usually means the rim is bent, much like mechBgon said. However, I would disagree on the idea of building a new wheel with straight gauge spokes, regardless of manufacturer. A stiff rim with double butted spokes is the way to go for greatest strength. You see, that stiff rim will not flex as much, but since butted spokes are "springier" than straight gauge spokes, the force of an impact will be distributed among a larger number of spokes. I won't give my usual "lifetime spoke breakage and truing warranty" on any wheel unless I've been allowed to spec butted spokes(and hub flange washers when necessary). I'll build whatever people want, but I can't remember the last time I built a wheel with straight 14 or 15 gauge spokes.

To clarify, I think your rim is bent. It would help to know rim brand and model, lacing pattern and number of spokes.

Remember...bike wheels don't like side loads. And rear wheels are about a third as strong as fronts because of the dish. That is, the rim being offset relative to the centers of the hub flanges.

Good luck and please let us know what your shop says!

cogito,
you seriously have a lifetime spoke breakage and truing warranty?

you must not build wheels for bmx kids eh? ;)

the rims I have are Yo 2000 by Alex (or something like that, maybe Y 02000 by Alex?). that's what the sticker says. (stock rims on a $250.00 bike)

the lace pattern is 3 cross and there are 36 spokes.

does anyone do race lace? (all spokes on the outside of the hub instead of half on the inside)


I plan on ordering some quality rims (or at least one for the back) this week.

Actually, I do have a few pretty hardcore BMX riders on my wheels, and with the more experienced riders, I haven't had any problems. It shouldn't be too surprising that since bikes ain't exactly a cheap sport to do, the guys that do it lots are pretty easy on their equipment.

As for "race lacing", there have been lots of articles written by some of the better known wheelsmiths, i.e. Jobst Brandt nd others, the conclusions of which don't support any one particular lace method. The aim of race lace(all spokes are head in) is to increase lateral stability of the wheel. It's hard on spokes, so breakage is common. Unless you need the tiny little bit of extra stability, then I suggest forgoing it.

BMX wheels are tricky to build well! I hope your new one turns out well.

I'm not building bmx wheels.
but I know they take a TON of abuse, so I had to ask.....