CVT TRANNY MOD
Taking the CVT (Continuously Variable Transmission) apart and putting
it back together is easy. One nut holds it together, but take the
belt off before you remove the nut. Nothing will spring out of the
CVT unit when you pull it apart and it's easy to figure out where everything
goes.
CVT
My tranny was all gummed up when I took it apart, the centrifical weights
(little cylinders shown in photo) were scored up, and the plastic end caps
were worn down. I cleaned all the crap out of the tranny, greased
it (go easy on the grease or you'll have grease flying out the side of
the CVT and onto your leg while you drive it). I slapped it
back together and I gained about 5 kph (I didn't bother putting the little
centrifical weight retainers back in, they are 3 thin metal clips held
down by 2 screws a piece to hold the weights in place, and my CVT works
the same without them). I knew the front sheaves (pulley halves)
weren't closing together all the way so I pounded some small lead fishing
weights into the center of the centrifical weights using a punch (see the
photo below).
Punch, CVT weights, and lead
fishing weights
The heavier weights worked great and increased the top speed by another
10 kph (top speed now about 50 kph) while not taking away from the bottom
end by any noticable amount; I would recommend doing this mod, if
you aren't pleased you can always pound the lead out. I thought I
could get more out of it, so I went down to the local hardware store with
one of my centrifical weights in my hand. I bought a high grade bolt
with the same diameter as the weight (maybe slightly larger, but don't
go much bigger than 1 or 2 mm or it'll be geared too tall from a standstill).
The bolt had a long section without threads on it which is what I cut into
three sections and used as new centrifical weights. Buy a couple
of blades for your hacksaw while you are at the hardware store because
those high grade bolts will eat up your blade before you're done your first
cut (cutting the bolt into three sections took me about an hour, but it
would take much less time if you replaced the blade every half cut or so).
Also be sure to file any burs off of the end of the sections as they will
shred the insides of your CVT. Grease those new sections before putting
them in because you no longer have the plastic bushings to reduce wear.
I don't think this mod is particularly good for the CVT, but I'm sure the
parts that would wear out are cheap, and mine seem to be holding up just
fine after a few months of use. This added 8 kph to my ped (top speed
now 58 kph), but it is a lot weaker from a standstill and it really slows
down on the hills, too bad cause that 8 kph sure is nice on the flats.
The bottom end loss is not worth it for the top end gain with the bolts
for weights if you need to take decent sized hills in your daily ride,
and I just recently swapped back to the lead filled centrifical weights.
I would recommend pounding the lead fishing weights into the centrifical
weights for some more top speed, but don't bother with the bolts for weights.