Walt Hackensmith Design
photo CD of this bike featuring over 140 hi-res photos click
1979 Yamaha OW40 Bob Hannah
1979 AMA 250
National & Supercross Champion
In the late 1970's
the most celebrated rider in the U.S. was Bob Hannah. He
had just come off a very successful 1978 season completely
dominating the competition in the outdoor 250 Nationals and the
250 Supercross series. It was in 1978 that Bob set an AMA
record, winning 22 motos in a row. For 1979, the season
opened with the Oakland California Supercross. The 1979
works bikes were not ready yet and team Yamaha used their 1978
OW38 works bikes. It wasn't until the third round at the
Atlanta Supercross when the 1979 OW40 made its debut in the U.S.
Teaming with his long time veteran Mechanic Keith McCarty, Bob
once again won the 250 Nationals and 250 Supercross series.
These would be Bob's last Championships. He won them with
this bike. The bike is 100% restored and is about 90%
original. The parts that were not with the bike are
original OW40 parts. Keith helped with some of the small
things that were missing. (mostly some of the ti bolts etc.)
Keith also had the original folder that he carried around in
1979, with all of the original stickers that plastered the bike.
Even Jinny O'Brien that supplied the numbers, had the original
number ones leftover. These were donated for this
read the text in this feature, you will see how well this bike
was designed. It is the most refined of the original
monoshock bikes. The options the riders had and the attention
to detail is amazing. Another point about the bike is,
there is virtually nothing on it that interchanges with the
production bike of that year. I went to Red Bud with Roger DeCoster a few years ago with a bike very similar to this one,
and after he rode it, he was very surprised after so many years
how good it was. Anybody that saw Bob Hannah ride this
bike will never forget it. I was at Saddleback the day Bob,
Danny "Magoo" Chandler and Marty Tripes were the only ones
clearing the 4th gear flat out "Magoo Double". It was
motocross racing at its finest. This is truly a full
works bike ridden by one of the greatest riders of all time.
Keith McCarty's Comments:
time suspension travel was reaching 12 inches plus and everyone
was going in that direction. The problem was, in making real
tall bikes, they wouldn't go through the corners well. We
went in the other direction. We wanted to make our bike
real low and also have lots of travel. We didn't care if
the frame hit the ground or the tires hit the fenders.
We wanted to maximize every millimeter that we could to keep the
bike low for cornering. We did a lot of private testing in
the Tehachapi hills. Even though the suspension was made
by Kayaba, we did not have an engineer with us. I was the
engineer. We did have a rep though that was very
instrumental for me at making the parts that I requested.
I had a lot weird requests because I wanted the bike real low.
The forks were very special inside. The tall fork caps
were to increase the air capacity of the fork, to change the
spring curve. I think that is one of the big things that
helped us win. Bob had as much travel as they did but his
bike was an inch and a half lower. We did have trouble
with the valving shims in the shock. Under the tremendous
load they would deform and we would loose damping. In some
ways, I think the stock shocks were actually better in that
regard. Our motors were not as fast as the others that
year. The chrome in the cylinders was not so good.
They would ruin pistons until the rough edges were worn off.
in fact they actually ran better after about three races.
Later we would hone them before we used them. We used this
same bike for outdoor Nationals and Supercross, it was just set
Bob Hannah's Comments:
It's hard to
remember the details of each bike 25 years later. They all
sort of blend together. When I look at my bike today, it's
just another works Yamaha. We really worked hard to make
the bike low and maintain the suspension travel. Keith and
I did a lot of testing in the Tehachapi hills. We always
went there to test. We lowered the bike and my
cornering speeds were up as a result. The taller bikes
just did not turn. For sure, we were the only ones to do
this. We were also content with a bike that made good
mid-range power (for a better drive out of the corners) versus
top end. I was content with the small rear hub because I
didn't use much rear brake and the smaller one was lighter
anyway. Our bike was also very light (around 200 lbs).
With out a doubt the biggest improvement we made, was to make it
lower. It gave us a huge advantage over the competition.
Once we got where we wanted it, all I did was worry about