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            Walt Hackensmith Design

                     For a photo CD of this bike featuring over 140 hi-res photos click here       


                            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 restoration.

  When you 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: During this 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 up differently.

   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 winning races.





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