Wheel truing 101?

On Thu, 12 Apr 2007 09:31:34 -0700, Mamba wrote
(in article <[email hidden]>😉:

Quoted message said:

I have an older Trek being used as my commuter. It has an older, but
decent, wheelset on it with rim (V) brakes.

I've always noticed a major rub when braking on the front wheel. That
grab/release feeling when lightly applying the brakes. So I finally threw
it on the stand a couple of days ago and spun the wheel, looking for the
wow. I found and marked the chunk of rim that appeared to be the culprit
and grabbed my spoke wrench for my innaugural attempt at wheel truing.

The wow seemed to encompass about six inches of rim, so over that area I
gave the "wowed" (towards brake pd) side spokes a 1/4 turn loose and the
corresponding other side spokes a 1/4 turn tight. It seemed to work pretty
well, the wow was greatly reduced. I figured I'd ride it for a couple of
days and see how the stresses were redistributed.

Now it's a couple of days later, and the big wow is mostly gone. What I
notice now is a lot of little grab/releases. I'm assuming this is due to
minor wows in the rim that I didn't notice before because of the bigger
problem.

So, my wheel newbie questions:

Does working on one section of a wheel rim often/usually cause another
section to go out of true?

It can. I always look at the wheel as a whole when truing.

Quoted message said:

Is it worthwhile to try to get rid of all the little wows in the rim?

You should be able to get it to a point where you won't feel it pulsating
through the brakes.

I've

Quoted message said:

been using discs on my other bikes for years, so wheel perfection isn't an
issue there.
Is there a reasonable way for a newbie to judge correct spoke tension? I
have read a couple of articles by wheel experts, and it seems testing by
hand is almost an aquired art. Any tried and true simple methods
recommended?

I true by ear- plucking the spokes and comparing the sound with other spokes
on the same side of the same wheel. I've used Jobst Brandt's book "The
Bicycle Wheel" and Sheldon Brown's site
http://sheldonbrown.com/wheels/index.html as references.
You should also look the rim over carefully for splits or dents that could
cause feedback through the brakes. It's also important to stress relieve the
spokes after truing. This is discussed in Jobst's book. As with any other
skill it takes some practice to acquire. good luck.

Paul

Quoted message said:

Cheers
Gary

Quoted message said:

Does working on one section of a wheel rim often/usually cause another
section to go out of true?

You should have adjusted the spokes on the opposite side of the wheel,
not just the ones on the opposite side of the rim.

Quoted message said:

Is it worthwhile to try to get rid of all the little wows in the rim?

How much free time do you have?

Quoted message said:

Is there a reasonable way for a newbie to judge correct spoke tension? I

It used to be done by the tone of the spokes. I prefer a $50 Park
tensiometer, and an Excel spreadsheet.
http://www.parktool.com/repair/howtos/TCC_version10.xls

Quoted message said:

have read a couple of articles by wheel experts, and it seems testing by
hand is almost an aquired art. Any tried and true simple methods
recommended?

Try this book, it's a good start.
http://www.amazon.com/Bicycle-Wheel-3rd-Jobst-Brandt/dp/0960723668

CowPunk said:

Quoted message said:

Does working on one section of a wheel rim often/usually cause another
section to go out of true?

You should have adjusted the spokes on the opposite side of the wheel,
not just the ones on the opposite side of the rim.

'Splain that one, if you would.

Shawn

Shawn said:

CowPunk said:

Quoted message said:

Does working on one section of a wheel rim often/usually cause another
section to go out of true?

You should have adjusted the spokes on the opposite side of the wheel,
not just the ones on the opposite side of the rim.

'Splain that one, if you would.

Glad you posted that. I thought it was just me being thick ;-)

G

Quoted message said:

Shawn

Gazza said:

Shawn said:

CowPunk said:

> Does working on one section of a wheel rim often/usually cause another
> section to go out of true?
You should have adjusted the spokes on the opposite side of the wheel,
not just the ones on the opposite side of the rim.

'Splain that one, if you would.

Glad you posted that. I thought it was just me being thick ;-)

To keep things in round.

Greg

--
The ticketbastard Tax Tracker:
http://www.ticketmastersucks.org/tracker.html

Dethink to survive - Mclusky

"G.T." <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Gazza said:

Shawn said:

CowPunk wrote:
>> Does working on one section of a wheel rim often/usually cause another
>> section to go out of true?
> You should have adjusted the spokes on the opposite side of the wheel,
> not just the ones on the opposite side of the rim.

'Splain that one, if you would.

Glad you posted that. I thought it was just me being thick ;-)

To keep things in round.

Greg

If I adjusted the spokes in opposite directions (some tighter, some looser)
at the point of the wow, doesn't the "net" tension on that side of the wheel
remain static? How can this affect the roundness of the wheel as a whole?

Tnx
Gary

Mamba said:

"G.T." <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Gazza said:

Shawn wrote:

> CowPunk wrote:
>>> Does working on one section of a wheel rim often/usually cause another
>>> section to go out of true?
>> You should have adjusted the spokes on the opposite side of the wheel,
>> not just the ones on the opposite side of the rim.
> 'Splain that one, if you would.
>
Glad you posted that. I thought it was just me being thick ;-)

To keep things in round.

Greg

If I adjusted the spokes in opposite directions (some tighter, some looser)
at the point of the wow, doesn't the "net" tension on that side of the wheel
remain static? How can this affect the roundness of the wheel as a whole?

It doesn't. If, for example, the rim is further from the hub over four
spokes, causing it to bulge out radially along that length, and you
tighten those spokes to pull the bulge in, the overall spoke tension of
the entire wheel increases, but not much, and the increase isn't
localized exactly opposite to the site you just tightened. Rather it
gets spread to all of the spokes. A spoked wheel doesn't behave exactly
like a rigid disk.

Shawn