Commuting - brake rub -- need to "true" wheel?

hey all,

my rear tire is rubbing up against the right brake pad, but only about once a revolution (from what I can tell initially) -- the rest of the revolution, it appears to be somewhat centered between the pads... would this likely indicate that the wheel is somehow crooked? does this mean that I need to "true" the wheel, as I've heard people mention? if so, I can google that and probably figure it out, but I wanted to find out if this is indeed the likely issue.

(in the meantime, for my commute home, I've just adjusted the right brake pad way out to avoid rubbing on any part of the tire, but it is way off-centered now)

thanks!

Yes. Your wheel needs to be trued. You will need a spoke wrench to do it. Personally, I suck at it. I can do a very rough job, but when I want it done right, I take it to a shop.

You may have broken a spoke.
Check all the spokes in the area of where it contacts

the wheel is in need of truing, or as that other guy mentioned it could be a broken spoke/nipple/eyelet. sheldon brown (http://www.sheldonbrown.com/tooltips/truing.html) and park tool (http://www.parktool.com/repair/readhowto.asp?id=81) both have excellent guides if you want to tackle this on your own.

All you really need is a spoke wrench, truing stands and tension-meters are nicities but not necessary.

Yup, that is what you need to do. Your rim is slightly out of flat. I'm sure that there is a good description on the 'net, but what you need to do is get a nipple wrench of whtever size your spoke nipples are, and then tighten the spokes near where the rub is until the wheel spins true.

thanks all for the replies. I'm going to give it a shot, but I'm envisioning a trip to the bike shop in my near future. ; )

I have trued my new front wheel a couple of times recently so I have gone from being a complete newbie to vaguely experienced. As someone else suggested start by checking to make sure none of the spokes are broken. Broken spokes probably call for an LBS visit.

If all the spokes are intact I highly reccomend the Park site instructions. Before trying to true the wheel I would go around and squeezing pairs of spokes look for anything that seems unusually loose and snug those up. When I did my wheel I marked the loose spokes and as I made my adjustments to true the wheel I paid extra attention to the loose spokes. You will want to make sure you follow directions/suggestions for relieving the spokes. I didn't do a good job of that the first time around and my wheel was out of true in about a week. The second time around I worked hard on relieving the spokes and the wheel has been true for a couple of weeks now.

Just take your time, keep your orientation to the wheel and spokes consistent and be prepared for it to take longer than it should and you'll be fine.

thanks, mdnewbie -- I actually did find one very obviously loose spoke, so I've marked that -- I think I'll need to visit the LBS this weekend, but hopefully just to pick up an appropriate sized wrench.

after that, hopefully all I'll need is patience and practice. ; )

Get the wrench that looks like a doughnut. It has a wide range of sizes and it's great to work with, small too.

i recommend only park spoke wrenches... they cost more but the cheaper ones never seem to fit right and you end up rounding off your nipples (which is easy cause they are sometimes pretty soft).

maybe other companies make good spoke wrenches but there are plenty of garbage ones out thre!

definitely read up on wheel truing before attempting to do it. the first time i tried to do it without knowing what i was doing, i wound up making a mess of a wheel. it's not terribly difficult, but it's good to know what you're doing.

otherwise, you can take it to a shop and they'll charge you a few bucks.

Yes. Your wheel needs to be trued. You will need a spoke wrench to do it. Personally, I suck at it. I can do a very rough job, but when I want it done right, I take it to a shop.

If you want to use a spoke wrench, by all means do it. But it's not actually necessary. I use an adjustable wrench, because I've never had a spoke wrench, and because i find it quite easy to use an adjustable wrench.

I also use the bike's brake pads to tell me whether the wheel is true/round.

definitely read up on wheel truing before attempting to do it. the first time i tried to do it without knowing what i was doing, i wound up making a mess of a wheel. it's not terribly difficult, but it's good to know what you're doing.

otherwise, you can take it to a shop and they'll charge you a few bucks.

+1
For example, never tighten one side without loosening the other side slightly or else you'll end up throwing the wheel out of radial true or even worse ,over stressing the rim and breaking it.

well, I've gotten myself into a little mess. ; )

I bought a spoke wrench, only to arrive home and find that the spoke nipple was now missing entirely, and therefore could not be tightened. Needing to take my bike out that night, I decided to check if the spoke nipples on my old mountain bike were the same size, thinking I could just swap one out temporarily to get my bike in working shape. They were, so I began unscrewing. Unfortunately, it seems that unscrewing spoke nipples on my mountain bike lets the air out of the tire, and yet does not allow them to come entirely loose. So now my mountain bike wheel is out of true, and I cannot get the tire to hold air -- I wonder if I've done permanent damage to the wheel/tire by unscrewing the nipple so far? Oh well, low priority...
I eventually discovered that the commuter bike nipple was rolling around inside the wheel rim. So I took off the tire & tube, and eventually got the nipple out through the valve stem hole. However, the base is too thick to put into the spoke hole from the outside, so I'm thinking I have to get it back in from the inside of the rim, which sounds like it'll take way too much patience / luck... How do bike shops add new spoke nipples?


thanks all....

They normally have a nipple driver which makes life a lot easier. However, when I built my last wheel I just used a narrow set of pliers and got quite proficient at getting the nipple as far into the rim as possible, then dropping it the last few mm's. Once you have the nipple in, use a flat head to hold it in place while you manoever the spoke in place. Do you have any flaxseed oil? This helps to make the nipple less susceptible to loosening. Apply some to the spoke threads before you start messing with the nipple. Oh yeah, definelty make sure your spoke is threaded right wrt to the other spokes before you start anything. Finally, remember when using a spoke wrench that everything is opposite, i.e. turn spoke wrench right to tighten and left to loosen.

There is a reason the nipple does not fit through the hole; it is designed to pull against the rim at that point; it's how the spoke attaches to the rim. You need to drop the nipple in from the back.

You must have a double-wall rim if you are able to have the spoke nipple rattle around inside of the rim. The cross section of the rim looks something like this:

http://www.lickbike.com/lickimages/2092.gif
http://www.lickbike.com/lickimages/2092.gif

You need to unmount the tire and tube, and remove the rim strip or rim tape from beneath the tube. You will find a hole on the inner wall (where the backside of the inner tube pressed) corresponding to each nipple hole. The easiest way to put a nipple into a deep rim is to thread a spoke a little ways into the nipple backwards and use that as a skewer to reach it down into the hole from the back side. If you are building a whole wheel or do this a lot, you'll probably get good at just dropping them into place or something (much faster in the long run).

When you tried to remove the nipple from the other wheel, it sounds like you encountered a single-wall rim, where the inner tube presses directly against the backsides of the nipples. I'm not sure what would cause the tube to rupture and deflate unless you tore the rim strip/tape that protects the tube from the sharp spoke ends and nipples and nicked a hole in the tube by turning the nipple.

When you are installing, removing, or adjusting spoke nipples, it is very important to turn them the correct direction. The threading is righthand, just like most common screws, nuts, and bolts, but due to the way you usually end up looking at a spoke nipple installed in a rim, most people find that the directions required to tighen and loosed the nipple are backwards of what their initial thought was.

If you are not absolutely sure of what I mean, get another (unmounted) spoke and nipple to hold next to the one you are working on and experiment with the unimportant one to see what direction of rotation does what.

GGDub, MacG -- thanks much for the detailed info. I hope to have time to work on this by mid-week.

Greatly appreciate the insight!

i recommend only park spoke wrenches... they cost more but the cheaper ones never seem to fit right and you end up rounding off your nipples (which is easy cause they are sometimes pretty soft).

maybe other companies make good spoke wrenches but there are plenty of garbage ones out thre!

Nipples soft and round ... what is wrong with the world!

You will save a lot of money in the long run if you learn how to true your own wheels, plus much more confidence in the wheel. I used to have to pay $16 for a wheel true, yikes. Just buy a spoke wrench and start playing with it. Buy both the black and red one, because I can never remember which one fits which gauge spoke. and then use the one that fits the nipple. doh.

oh yeah, a word of advice. only make small adjustments, say quarter or half turns. and only worry about the horizontal true. vertical true you can live with for a commuter. at least that's my experience. invest in a truing stand when you have some spare cash, it will feel good after you go completely insane from truing to your brake pads!

You need to unmount the tire and tube, and remove the rim strip or rim tape from beneath the tube. You will find a hole on the inner wall (where the backside of the inner tube pressed) corresponding to each nipple hole.

To clarify, you're saying that I can remove the thread/tape that goes around the perimeter of the rim, in order to access the nipple hole? Does the thread/tape go easily/smoothly back on? or do I need to buy a new tape? or do I need to re-add glue?

thanks...

do I need to buy a new tape? or do I need to re-add glue?

for all of the rims i've seen, you can remove and reinstall the rim strip without adding glue or buying new tape.

in case anyone is still interested, I did get the nipple out of the rim, and got the spoke back in. after a lot of trial and error, I've got the wheel in pretty decent shape. not perfectly trued (horizontally) to be sure, but close enough to avoid hitting the brakes, for the time being. I'll probably pay someone to do it well in a couple months when I get a good tuneup, cause I understand it can reduce performance / efficiency considerably.
In the meantime, it was good to learn another repair skill. ; )

Thanks again for the help...