heirfaus

So my girlfriend just bought a bike in a box from Nashbar. Decent price and exactly what she needs for her entry level riding. I assembled it and noticed that the rear wheel wasn't true. After my headset headache (which I now know far more than I wanted to ever know about headsets) I have now performed pretty much all forms of bicycle assembly, maintenance, and adjustment.....except wheel truing!

Seeing that her's weren't true, I decided to check mine. The front is great but the rear has one spot where moves towards the brake shoe. Here's my problem. I have been doing some research online about wheel truing, but I found two sources (one being Sheldon Brown) that says adjusting spokes individually to compensate for a wheel being out of true is improper and shouldn't be done. Local shops say it's fine....

Who do I believe? I'm confident I can adjust the two or three spokes necessary to true the wheels up nicely, but I don't want to perform improper maintenance.

Any suggestions on how to proceed?

Oh yeah, and plucking her spokes creates drastically different notes, front and rear wheels.

Kimmo

If you compare the tension of your spokes, you may find some are much looser than others, in which case all bets are off until you de-tension and re-tension the wheel. If your tensions are fairly uniform, then it's generally a bad idea to adjust individual spokes.

Whether you should obey Sheldon depends if the rim is bent, which can be hard to tell without separating the rim... if it's a smooth wave rather than a sudden blip, your rim is prolly okay, but it depends on the strength of the rim whether a tighter bend means it's permanently bent.

First attempt to true the rim by adding any tension you remove from one side to other. If you don't do this, the wheel will go out-of-round, and develop a 'hop'. If it's a tight bend that stubbornly refuses to respond, this unfortunately means your rim is prolly bent, and really should be replaced.

To get by in the meantime, you can crank on those spokes any old how to try and get the rim straightish, but don't forget the roundness factor - it's far more preferable for the rim to move side-to-side by 5mm than up-down. With a damaged rim, you're really just trying to get the rim to stop rubbing on the brake pads, since making it perfectly straight is bound to make it out-of-round.

Some folks can sort of 'repair' bent rims by whacking them on the ground or standing on them, but YMMV depending on how many brain cells you bring to the exercise.

When I disassemble an old wheel, I find the best way to check the rim is to hold it against a pane of glass. Roundness off the hub can be checked by turning it against the wall in a corner of a room.

the_don

Just watch a youtube video and don't worry about it.

I like to attack my truing by adjusting at least 4 spokes for a wobble. 1/4 turns tightening spokes to pull a direction and 1/4 turn loosening spokes that pull the rim the other way to ease the pressure. Then I spin the wheel to check how much it has straightened and repeat as necessary.

I have seen a video where the guy says to just find one spoke closest to the affected area and tighten until the rim is straight. That seems to work on the video, but might end up with very uneven spoke tensions.

Kimmo

Yeah, that's stupid. I bet the guy only showed how he straightened it laterally; that half-arsed method is bound to induce hop.

dabac

The holy grail of wheel longevity is "high" and "even" spoke tension.
Assuming your wheel was OK to start with, adjusting only a few spokes will pull it away from this theoretical ideal.
But maybe your wheel is out of true b/c a few spokes are too high, or too low? In that case, touching up only those spokes will bring it closer to the ideal.
W/o knowing the status of your whole wheel there's just no way to tell.

Trouble is, there's not really an overall useful limit on how high and even tension has to be to give a functional wheel. A light, occasional/casual rider can get away with just about anything, while others might need a wheel that's right up by the practical limit not to fail on them.
Whenever you're dealing with a wheel with some history in it, you usually end up with some sort of compromise between tension and trueness, with tension being the first priority.

Kimmo

If you're a big guy who jumps gutters and stuff, high and even tension is critical.

Also, when replacing a rear rim, go for an off-centre rim to enjoy the free lunch.

heirfaus

Thanks for the quick replies. So it sound it will be better to attack them by 1. making sure there is even tension and then 2 making sure it's true as possible. Quick question?

When setting the tension, the tighter the spoke the higher the pitch, correct? In theory, I could pluck the spokes and find the highest pitch and then set all of them to that so I will have equal tension to the highest set spoke, while trying to maintain them as true as possible also, right?

Is it worth buying the Park tension tool. Being an ex auto tech I love having the right tool for the job, but hate pending money when not needed. BTW my longest rides are about 40 miles right now, but hope to be at 100 miles by the end of the year so I will be putting on a lot of miles and hope to have things tip top

Kimmo

I just use the stress-relieving grab around the wheel to get a feel for tension (when building a wheel you grab bunches of four spokes and squeeze them hard to bed in the spokes)... after going around the wheel a couple of times loose or really tight spokes are noticeable. I don't usually go off the pitch from plucking, cause I find it takes longer and I'm not sure my ear is good enough.

Dude. Come on... someone who's never even seen a stringed instrument should be able to figure that out from first principles. Go and play with a rubber band.

dabac

Well, it's a bit of a dual process. They both influence each other, so you can't really do them entirely separately. I like to think of it as I monitor trueness while I work the tension up. Then I do the tighten-and-slack thing when I focus on trueing. Then it's back to tension checking, seeing how even I can get it w/o upsetting the true.

Yeah, there's even some hints on what pitch to listen for available - If you've got the ear for that...

True, assuming that the highest spoke is a good target to aim for, and that you have the ear for it. Remember that externally geared hubs need to have different tensions left/right.

I think so. If you ever run into issues it gets ever so much easier coming up with explanations and fixes when you have a measurable value available. W/o that, the most probable explanation to the majority of wheel trouble is "insufficient build quality".
After the nth wheel most people develop some kind of "feel" for it, but I'll happily keep using my meter at the final stage anyhow.
Besides, w/o the meter I don't know what kind of tension my "feel" would have had me aiming for...
Even short rides add up, and it sure is nice not being let down by equipment.

MichaelW

Truing is usually finding the compromise between trueness and even tension.
If I want to remove a localised side wiggle I usually attack 3 spokes, tighten the "innie" and slacken the "outy" side but only by 1/8 turn increments.
Spokes need to be tight enough to retain their tension under max compression so they are not just loose bits of wire. I'm not sure that higher tension adds much strength but then I'm not well versed in the dark arts.

Kimmo

Higher tension prevents the spokes from going slack and fatiguing. It also makes the wheels handle better, or at least tension that's too low makes your wheels all noodly and useless for hard cornering.

davidad

Go for the tensiometer. It's the only way to get balanced proper tension.

wrk101

+1 Slightly loosen 3 on one side, while tightening the same amount 3 for the other side.

Tensiometer is the way to go but kind of pricey. I just picked one off CL used. Been adjusting for years without one, I am sure I will do a lot better with some real data.

Drew Eckhardt 

I measured the last two wheels I built with no tension meter and the Jobst Brandt tensioning method for lightish box section rims with conventional spoke counts (alternately add tension and stress relieve until the wheel deforms in waves indicating you've reached its elastic limit at which point you remove half a turn, re-true, and be happy until you bend the rim or wear out the braking surfaces).

The front (Reflex Clincher, 32 DT 2.0/1.5 Revolutions, Campagnolo hub) measured 110kgf average +9, -5% without a tire installed except at the bend which had me replacing it.

The rear (Open Pro, 32 DT 2.0/1.5 Revolutions NDS and 2.0/1.8 Competitions DS) measured 110kgf drive side with a tire installed and similar tension variation.

That's exactly what I'd get building with a tension meter on front and very close in back (the tire drops tension somewhat, so I should have ended up with a little less shooting for 110kgf drive side with no tire installed).

The tension meter is just faster and works for deep rims and/or low spoke counts.

heirfaus

Thanks so much everyone! This site is a great source of help! Looks like I will pop for the tensiometer.

Quick question about the meter. The description of the tool says it's good for all kinds of spokes. Will it actually work the same on my girlfriends new skinny spokes as it will on my thicker bladed spokes?

Drew Eckhardt 

Most likely. The chart includes measurements for round spokes down to 1.4mm and lots of steel/aluminum bladed numbers.

You might take a look at the Conversion Chart to guarantee your favorite bladed spokes are in the chart.

Lawrence08648

I never true wheels for the first time without first checking the tension. If I've checked the tension and previously and adjusted the tension, I usually don't do it again.

Anytime you adjust one spoke, you affect every spoke.

You never adjust the spokes on one side without adjusting the spokes on the other side. If you loosen one side, you tighten the other side, this is to maintain equal tension.

If one spoke needs adjustment, you usually adjust the spokes on each of the sides of that spoke if not two on each side plus the spokes on the other side.