From: thomas@bitrot.in-berlin.de (Thomas Driemeyer)
Subject: Re: Rebuilding Wheels
Organization: Thomas Driemeyer, Berlin
Date: Thu, 8 Oct 1992 19:04:29 GMT

In article <1aspslINN767@rio.crhc.uiuc.edu> jgholm@crhc.uiuc.edu (John G. Holm) writes:
> I can order DT spokes from NASHBAR for << $0.50/spoke.
> Should I do this myself?  I would prefer to do this
> myself, but I fear that I will spend more on tools and
> parts than I would just having the bike shop do it.
> How hard is it to replace the spokes on both wheels?
> I expect the rear wheel is more difficult because I
> would at least have to remove the sprockets from the
> freehub.

It's simple. All you need is the freewheel remover, and a spoke wrench.
Plus something to cut the old spokes, unscrewing rusted nipples is usually
impossible. The Shimano freewheel remover costs a few dollars, and is a
small tool that fits into the freewheel or cassette (same tool) with a hex
nut outside. If you have a freewheel, you'll need a huge 24mm hex wrench,
and a friend who holds the wheel. Freewheels get REALLY tight. Cassettes
are much easier to remove.

Next, replace spokes one by one, cutting out the old one and replacing it.
Make a note of the lacing pattern (the spoke crosses over some spokes and
under others, this is very important) and tighten the nipple until you can
see only the last two threads of the spoke. Don't mix up the spokes for
the front wheel and the left and right spokes for the rear wheel, they
have all different lengths. (Measure the old spokes before ordering new
ones. *Calculating* spoke lengths is a black art.) 

You might want to replace the rim at the same time. If you do, use scotch
tape to tape it on top of the old rim, and simply move the new spokes
there. Depending on rim, make sure that the valve holes line up, and that
the spoke holes point in the same directions on both rims (some rims have
asymmetrical holes, they are angled alternatingly to the left and to the
right. DON'T get this wrong if this is the case.)

When all spokes are replaced, the wheel needs to be trued. Tighten the
spokes by making clockwise half-turns all around until all spokes feel 
tight. On the rear wheel, the right spokes should be much tighter than
the left ones to pull the rim to the center, because the right flange
is much closer to the center than the right, because of the freewheel.

If all spokes are tightened, adjust spokes so that the hub is in the
center. I do this by installing the wheel in the frame, and holding a wet
sponge to the tread. Bumps will get wet, and I tighten the spokes there.
Next, you have to eliminate the lateral wobble. In place of the sponge, I
adjust the brake until the right pad almost touches the rim, and then 
adjust the spokes until the rim doesn't rub anywhere. Then I do the same
thing on the left. Never turn a nipple more than a quarter-turn at a time.
For bladed spokes, turn a bit more than a quarter turn, and then back to
unwind the spoke. If everything is fine, pull every pair of spokes together
as hard as you can with your hands, and correct any wobble that this might
introduce.

After 100 miles or so, re-true the wheels if necessary. Some people dip the
threads of the spokes into linseed oil or wood glue before installing them,
or even use loctite on the nipples, but I haven't had much success with
that. You will find that the first wheels you build don't stay true as long
as wheels built by a bike shop mechanic, but you will get better with time,
and truing wheels is a useful skill to have.

Thomas
-- 

--
Thomas Driemeyer        thomas@bitrot.in-berlin.de        voice: +49 30 8924936
Newsgroups: rec.bicycles.tech