Bicycle Mechanics - True a wheel set

Can someone explain to me exactly what is means to true a wheel ? And how can you tell if your wheels need it ? I'm new at this but want to keep my wheels in good condition. Is it easy to true your own wheels once you know they need it ?
Thanks.:p

Ease of it all depends... some folks can do it on the fork with a pencil and rubber band. I get buy with an inexpensive truing stand. Some folks just find it easier to go to a shop.

Here is some info from Park tools. Wheel Truing (http://www.parktool.com/workshop/howfix_truing.htm)

If your rim "wobbles" from side-to-side, then it is OUT OF TRUE. Get yourself a spoke wrench (a good one, like a spokey, park, etc). It really isn't hard to true a wheel on the bike. Just remember, don't ADD tension to the wheel! For every spoke you add tension to, you have to remove tension elsewhere. I usually increase the tension in 1 spoke, then add about half that increase on the 2 spokes either side of it ON THE SAME SIDE OF THE HUB, then reduce the tension on the 2 spokes between, maybe a little on the spokes on the outsides, too. So, for 1 spot, that's 3 spokes increased tension, 2 or 4 decreased, total increase in tension: zero.

okay...now it is starting to make more sense. Not sure if I want to attempt quite yet but you never know. How does a wheel become wobbly ?

Go to this site:http://www.parktool.com/workshop/howfix_truing.htm

The true-ness of a wheel is how near to circular it is.
It should have a constant radius and the sides of the rim should be the same distance from the centre plane along the whole circumference.
Wheels are held in shape by spoke tension, but often, factory wheels don't hold their tension, or become damaged. Professionally handbuilt wheels are much stronger and hold their shape better.
You build and maintain the wheel using a spoke key. it is the cheapest bike tool, but capable of inflicting expensive damage. You have to use it with caution, no more then 1/8 of a turn at a time, when correcting an out-of-true wheel.
There are some good books and readings, the best being The Bycicle Wheel by Jobst Brandt.

Trueness of a wheel refers to side to side alignment or straightness of the rim.
roundness refers to how circular the rim is- Are there high spot or flat spots?
If a wheel is out of true due to a loosened spoke, very common, it is generally not necessary to loosen another on the opposing side.
For high spot- tighten the spokes under it, you may need to loosn spokes on alow spot somewhere else on the wheel
For a flat spot- usually a shop operation ther ARE tools to pull flat spots out, if you're ingenious you can make your own tool, it's not that hard, a lot of shops prefer to rebuild the wheel with a new rim.
Ride true and round
Pat

1/8 th of a turn??? Get real!!! That would take all day to true a wheel. How do you relieve twist with only turning 1/8 each turn? Turn back 1/16 of a turn?
I would suggest to the beginner, never exceed 1 turn, but always back-off 1/4 turn. Click onto Sheldon Brown's site for more complete details.
Finer adjustments require smaller turns, but limiting yourself to 1/8 turn on a seriously out-of-true wheel is like cleaning your house with a toothbrush.

This is what Sheldon Brown has to say about trueing at
http://sheldonbrown.com/wheelbuild.html#tensioning

"
For example, if the rim is off to the left, and the center of the bend is between two spokes, tighten the spoke that goes to the right flange 1/4 turn, and loosen the spoke that goes left 1/4 turn; If the center of the left bend is next to a spoke that goes to the right flange, tighten that spoke 1/4 turn, and loosen each of the two left spokes next to it 1/8 turn; If the center of the left bend is next to a spoke that goes to the left flange, loosen that spoke 1/4 turn, and tighten each of the two right spokes next to it 1/8 turn.
"

The best advice is to take the wheel in question to a GOOD bike shop where they will charge you for a good truing job.

If you want to learn how to true a wheel, learn on an inexpensive wheel that you are not afraid of screwing up on.

There are many factors that come into play when truing a wheel, the roundness, the truness and the DISH. It is very easy to screw up the dish of a wheel if you are not careful and it is probably the #1 reason why bikes do not track well.

Dish is the overall side to side relationship of the wheel. Rear wheels need to be dished and so do front wheels. A front wheel that is even so much as an eighth of an inch out of dish will affect the tracking of a bike greatly.

You can learn a lot by working on a old used bike instead of your number one steed. Pick one up for $200 or so and ride it around after you fix it up. A great way to learn about bike wrenching instead of potentially ruining your best bike.

If you have to ask this question, please let a shop do this for you. I seem many trying to fix these adn end up making them worse. I feel bad in these cases.

However some try to blame the rim manufacturer or the shop where they bought for their mistake. This I no longer tolerate.

If the rim simply is not straight it will need to be "trued"

Thanks for all the explanations. I understand now.
Xavier...as I said earlier in my thread, I'm new to this, if I don't ask questions than I will never learn. I also stated that I would probably not attempt this at this point. I'm not experienced enough to work on my own bike yet. But I will take Felix's advice and try to true a wheel from an old bike. I don't want to have to take my bike in everytime something is wrong. I want to be able to twik my bike if it needs it. And I'm not the kind of person that blames my mistakes on others !!!! Calm down ...take a deep breath and relax !!!

You should also try and build a wheel. It sounds tough, but in truth it is the only way to understand how a wheel works and how to best true up a wheel.

Give it a try sometime, you might find you are better at it than you thought you could be. There are directions on how to do this, Brandts book is a good one and the sheldonbrown site also has some good directions on it.

mascardr,

Great. Always good to know someone wants to lear. Just from experience as a shop owner we get many that attempt this and end up blaming us for this as they may have purchased the wheel here.

I am glad to see that you may not be this type of person.

Truing a wheel is pretty easy. Simply takes practice.

rim moves to the left. Tightene the right (opposite) spokes on that section. Little by little. Hops are a bit harder but same concept.

Here's a tip for all you wheel building dudes,to relieve the spoke's of "twist" as your building/tensioning the wheel..sit on a chair,put one half of the rim in your lap,rest your elbows at 8 o'clock and 4 o'clock on the rim and your hands at 10 o'clock and 2 o'clock on the rim , and press down on the rim with your elbows repeat this 4 times, a quater turn each time and you will hear the spokes loosening themselves as it's done..then retension and do it again ...one tip :DO NOT PUT TO MUCH PRESSURE ON A UNTENSIONED RIM !!.... this procedure is done when the wheel is nearly up to full tension..:)

I think it's always useful to learn how to true a wheel just in case you need to get some adjustment if a spoke breaks when on a run and causes the wheel to twist badly. (I've seen it happen!)