Patrick Keogh said:
Bill the Cat said:Hi all,
Ahh a long weekend but sick as a dog so I can't ride. I was just looking at
the different hub dynamos out there and wondering whether building one's own
wheel is possible.
I kind of know that it is possible as I built a touring rear wheel as a kid
without any tools other than a spoke key and time.
However, it was *NOT* a good wheel - the lateral movement was minimal but it
had lots of "dips" and some really freaky loose spokes.
I am thinking that it would be fun to try a front wheel (25+ years later).
Can a lay person make a professional front wheel without, say, a spoke
tension meter or are there other tools required as well?
Then there is the choice of rim - it is for my commuter, but I want to do
some touring on it as well. Any suggestions?
Thanks,
BtC
Jobst Brandt's book on the Bicycle Wheel is a very good reference book.
It is my wheel building bible.
You need a truing stand, a spoke wrench and time. That's all. It is a
great winter evening activity in front of the TV or listening to music.
A truing stand is really only needed for the practised professional
who can build a wheel in an hour.
I've cycled 110,000 kms on wheels I have built.
They used to have 36 spokes, but now I have aero CX33 Mavic which are
strong as older D mavics
with 36.
I just have the bike turned upside down and use it as the stand after
roughly lacing the wheel in my lap.
I use a 3 cross pattern everywhere.
I get all the spokes in with nipples wound up so the thread just
dissappears from view.
The wheel still has all loose spokes, but can be put into a bike frame
and each spoke it wound 1 turn each all around, then again and again
as the tension nears where you want it, so you need to know
when the tension is about right. Not too tight, not too loose.
I just sort of know, after so much practice.
If in doubt, compare your wheel in a bike shop to what the
tech man does and other bikes.
Something metal can be held in the forks to gauge the straightness of
the wheel
while turning it around.
Its important to get the rim centralised, and without hills and dales
larger than 1/4 of a mm.
When the rim is within 0.25mm of being true both sideways and up and
down,
then you'll find the spokes are nearly at equal tension.
Rear road wheels are a little fiddly because the cassette side has its
spokes much tighter than the
other side, due to the angle of pull of the spoke, ie the "dishing" of
the wheel.
The front and rear rims should end up being exactly on the centre line
on the frame.
To ensure this I made a timber straight edge 2M long with 4 offset
struts of 100mm
whose ends are also in a straight line.
The straight edge can be used to set the wheels along a straight line,
and when eyeballing
front to rear and rear to front you'll see if the wheels also are
aligned on the dead centre
of the frame. Equal measures of frame should appear each side of the
rims.
Handlebar alignment is also done using the same tool.
The rims and frame should both be exactly in the same plane.
If when the front rim is dead plumb, and both are in line, then the rear
rim should also
be plumb. I use a builder's level.
And the rear rim should have equal clearance between rear fork legs, as
with the front rim
and its forks.
So sometimes you have to bring a rim over 1mm to get it right, and it
means loosening
spokes on one side, tightening on the other, maybe 1/2 a turn on all
spokes either way.
Start tightening/untightening at the tube valve hole and work around.
Don't answer phones while wheel building and turn off the tele!
Spokes tighter than the rest can snap sooner rather than later, and
cause fatigue in the alloy rim material and cracks develop.
A good wheel lasts a long while but eventually it secumbs to
wear from brakes and fatigue cracking.
Spokes should be adjusted every time you see a slight wobble in one.
Patrick Turner.
