Marconi would be aghast at this
I saw a photo of a rider who
mounted his transponder in his
crossbar pad. I was wondering
if this works?
It does and it doesn’t. It
depends on the quality of your
local track’s signal strength. As
a rule of thumb, we say that the
handlebar location and foam
padding would make this a
hit-or-miss mounting location.
We wouldn’t do it.
What the tire giants couldn’t do a
SoCal inventor could.
TUBELESS VIA TUBLISS
Since virtually every high-perfor-
mance vehicle uses tubeless tires,
I’m interested in the Nuetech
Tubliss system, but I can’t grasp
how it works. Can you explain it?
Tubeless motocross tires have
been around for 20 years (on
works bikes), but they have never
seen the cash register side of a
motorcycle shop. Why? Making a
tubeless motocross tire was too
complicated. It required a special
rim (to keep the air lock tight),
a rubber sealing bladder (to
eliminate leakage around the
spoke nipples) and messy sealant
(to keep sidewall flex from
burping air pressure). The
problem areas were so numerous
that most tire companies shelved
the idea of tubeless motocross
tires, except for Nuetech.
Instead of trying to seal the rim
to keep air in the tire, Nuetech
seals the gap between the two
tire beads with a special rubber
inner liner, which is a fancy way
of saying bicycle tire. Filling the
gap between the tire’s beads
with an inflatable rubber bladder
closes the open end of the motocross tire; thus, it becomes an
airtight chamber. It isn’t exactly
tubeless, though; the rubber bladder has a small bicycle tube in it.
There are different crank thread diameters, but they are few and far between on
THAT SILLY MILLIMETER THING
I recently started working on a 2003 YZ250. I checked engine and frame
numbers with a dealer and they said it was 2003. I ordered a crank and
top end, but when I put it together, I noticed that the crank end on the old
crank was 10mm and the new one was 12mm. I called my dealer and ran
through the engine numbers again; this time the engine came back as a 2002
YZ250F four-stroke. Will the 12mm crank work if I use my old stator and a
new flywheel from the correct model year?
There is a lot of confusion on this issue between the years, your dealer
and you, but here is the answer. The 10mm crank came on a 2002 model
and the 12mm is from a 2003 model. You don’t need a new stator to go
with the 12mm crank, but you will need a new rotor, nut and washer. The
YZ250 rotor for the 12mm crank is unchanged from the 2003 bike up to and
including the 2015. The rotor part number is 5UP-85550-01. There are no
10mm (2002) rotors in stock at Yamaha, but there are plenty of 12mm rotors.