|The Yamaha AT1MX Replica Project
|Before... Challenged both cosmetically and in the suspension Department, this AT1 was a "put
together" Dave Rymal had this bike sitting around. It is actually an AT1MX engine in an
Enduro frame. The good news was it already had a magneto ignition and the right gear box
ratios. There would be challenges to set the bike up for the Ahrma National in 3 weeks!
|Late Sept 2008
|Dave wrote "Hannah-Rymal
Rat Bike" as a sort of
release of responsibility for
this project. The Numbers
on the case show it to be a
1971 AT1MX engine.
|One of the situations you face when building an AT1 racer is, air filter clearance. Just under 3
inches is all you have to work with. Then there is the matter of the 18 inch front wheel. 18
inches ? I've seen pizzas bigger than that! It's like having two back wheels on the same bike.
The thing that is most scary about this fire breathing trail bike racer are it's 30mm forks.
|From all accounts these forks have dampening
that is , shall we say, ABSENT? I'm going to
have to make them work for the last two races
of the season. After that I'll do some kind of
conversion. The front wheel can't wait it will be
21inch first thing.
|With a mere 30mm to work with, these
forks just scream FLEX at you. So now
what? Slight rust on sanctions,more work.
|Goofy little stuff to deal with everywhere. Headlight ears, plastic clutch lever, bent bars,
threadbare seat, return spring broken on foot pegs, worn out drive chain and sprockets, air
filter missing, the back fender is worn through at it's outer edge from the over sized rear tires
rubbing it raw underneath all these years.
|Our Corgi, Happy, spends so much time with me, out in the garage, that when I asked him
what the AT1 needed, and was there anything I could use laying around, he sniffed out this
pair of used Works Performance shocks 13.5 inches eye to eye, and this used Yamaha
21inch CT1 front wheel. Good Boy, Happy! Scooby snacks all around!
|Too bad Happy can't work a computer, he could
have placed my bid on e-Bay for this AT1 fork
brace keep your fingers crossed for me! The seat
comes off, and goes down to my upholstery guy
Efren Mena at La Guadaluana Upholstery in Napa
Calif. 707-259-0710. He says somewhere between
50-65 bucks depending on how much he has to
build up the old foam. He is going to use heavy
duty naugahyde normally used for farm tractor
seats. This makes the seat the first part of the bike
to be removed.
|After the seat, next I pull both wheels. While I
have them off, it's time to service the brakes. If
you've ever restored a "Barn find" to service
you probably know this stuff. If not, the
following is the absolute least that should be
done, for your safety and the safety of your
fellow competitors. Without servicing the
brakes on a bike that has been mothballed for
a while, you run the risk of 1. them not
opperating and stopping you. or 2.Them
staying on when you use them. The reason
for this is the brake cam actuator shaft, if rusty
can stick in the brake backing plate. While
we're in here, we will scotchbrite the shaft and
the passage in the backing plate where the
shaft goes through. Clean and inspect the
plate,shoes,springs plus scuff shoes and
brake drums with sand paper. A light coat of
grease on shaft upon reassembly.