Indoor Smoker: 1963 Bultaco Sherpa S Flat Tracker

Two-Stroke Bultaco Flat Tracker from an AMA Hall-of-Famer…  

In 1959, Francisco “Paco” Bulto introduced the first Bultaco, the 125cc Tralla 101 (“Whiplash”), which proved itself immediately in the Spanish Road Racing Championship. The Bultaco won seven out of its first ten races, beating Ducati, Montesa, and MV Agusta machines — quite the auspicious start for the new Spanish brand!

Soon, Bultaco introduced a Tralla-based off-roader, the Sherpa S, which came in a variety of displacements: 100cc, 125cc, 175cc, and 200cc. The 220-lb Sherpa S 200 became especially popular among American riders, not just for scrambles and desert racing but flat track. In fact, you get the bike with a 19-inch front wheel if dirt ovals were your intended use.

“At fairground flat tracks all over the land, short-track riders were discovering just how good the little Sherpa handled in sideways action. It’s as if the bike had been designed with flat track as its major purpose.” –MXA

The ’63 Sherpa S flat tracker you see here was built by none other than AMA Hall-of-Famer Erv Kanemoto, one of the greatest tuners and engine builders the US motorcycle racing scene has ever produced. Kanemoto, who was born in Utah and grew up on a farm near San Jose, California, got his start working on two-stroke boat and go-kart engines with his father on the family farm.

In his 20s, after being laid off from a factory job, Erv began working as a mechanic in a Hayward motorcycle shop. Soon he was working on a drag boat, motocross, road racing, and flat track machines. 

“As Kanemoto became more involved in racing he started building custom cylinders for other racing teams. Word began to spread throughout West Coast racing of the talented new tuner from Northern California.“

In 1968, Kawasaki hired him as a tuner for several top-notch racers. Five years later, he began running a team with none other than AMA legend Gary Nixon — a partnership that would last for more than half a decade. A decade later, Freddie Spencer won the AMA Novice Road Race Championship on a Kanemoto-built Yamaha. Erv would be right there with Fast Freddie as he transitioned to the most elite level of the sport.

“Honda was just introducing its two-stroke GP bike, and with my experience in two-strokes I was able to work with HRC’s engineers and give them input on developing the motorcycles. Also, I was able to get input from Freddie, and that also helped guide the factory into making a motorcycle that suited his style.” -Kanemoto

All in all, Freddie Spencer would win three world championships with Kanemoto at his side. Later, Kanemoto formed his own GP team, winning a world championship with Eddie Lawson on a Rothmans-backed Honda. 

“In all, Kanemoto was the tuning force behind two national and six world road racing titles.” –AMA Hall of Fame

In a span of four decades, Erv rose from a humble shop mechanic to a world championship winning team owner and tuner, working with some of the greatest legends of the sport.

Erv built the bike you see here for his nephew Jay to race on indoor tracks in the mid-1960s. It was lost to history for some 50 years until Robb Talbott of the Carmel Valley’s Moto Talbott Museum discovered it in the back of a barn. Racer and restorer Robbie Cadwallader instantly recognized the bike despite its poor condition.

“When I saw it, I knew exactly what the bike was… The history behind it is I actually lined up on the line in 1967 against this bike on my 200 Sherpa S and raced against this bike at the indoor short track in San Jose.” –Robbie Cadwallader

The unique “donut” in the front downtube, which Erv added to accommodate the center-port exhaust of the ’66 Bultaco Metisse 250 engine, makes the bike instantly recognizable. 

Below, Robbie Cadwallader talks about restoring the bike back to its former glory, just as it would have been raced at the indoor short track in San Jose. This one-of-a-kind flat tracker will be crossing the Mecum auction block on Sunday, May 10, in Indianapolis. You can see the full listing here. 

In the Restorer’s Words…

The story according to racer and restorer Robbie Cadwallader, founder of Motocharities and The Scotts Valley Motorcycle Show:

This bike actually started life in 1963 as a Model 3 Sherpa S200. Since then, it actually has some pretty famous racing history. The bike was actually built in the mid-60s by Erv Kanemoto, who went on to be Kawasaki’s chief engineer in their road race program. He built this bike specifically to race indoor short tracks like San Jose or Monterey.

The unique feature of this machine is it’s a Model 3 chassis, which is low and handled really nice, but he put a 1966 Model 11 Metisse 250 engine in the bike. As you can see in some of the photographs, it’s very unusual because of what Erv did. This particular engine had a center-port exhaust. So what’s he do? He cuts the frame and puts a donut in it to be able to make the exhaust go through the frame.

He built this bike basically for his nephew Jay to race. The history behind it is I actually lined up on the line in 1967 against this bike on my 200 Sherpa S and raced against this bike at the indoor short track in San Jose.

The bike was actually found 50 years later in the back of a barn by Rob Talbott, who had the Talbot Museum down in Carmel Valley. When I saw it, I knew exactly what the bike was. Told Rob it was authenticated by Erv, and it was in really, really poor condition. So I got it from Rob when he closed the museum, brought it home, and did a complete restoration on the bike as it would have been raced at the indoor short track in San Jose.

A couple of unique features I did to the bike: I hand-formed my own number plates. As you can see, they wrap around the rear shock. The reason why I did that is back in the day, when it was such close racing, that was to keep guys’ tires out of the shocks because that would have almost performed a bad crash. So they could rub against them, but they’re not going to get into the shock.

This bike has a lot of unique features on it. It has a Tucker Rocky front spool with an Italian Borrani front wheel, brand new spokes, brand new nipples, and brand new K70 tires, which were the tire to run on the indoor short tracks.

Another unique feature about it, if you look on the left-hand side, it has no foot peg. The reason being the tracks were so short that when you come off of a corner, you have your foot down as you’re sliding the bike through the corner, you barely had time to even put your foot back up on the foot peg. So what we did is we just put a stub right there, and that allowed the bike to get closer to the ground going into the left-hand corners.

And as you can see, it was a Model 3 Sherpa S, and that particular model in ’63 to ’65 came with a reinforcement on the rear swing arm.

Spec / Build Sheet

• Sherpa S frame no. 2
• Rare model 3 Bultaco gas tank
• The owner states that the engine was built by renowned engine builder Irv Kanamoto
• Rare 250cc Bultaco with a centerport exhaust motor and a frame donut for the exhaust
• Original Amal side-bowl carburetor
• Leather Bates solo saddle
• Original Flanders handlebars
• 32mm front fork
• Sherpa S rear suspension
• Akront rear wheel
• Front spool hub Tucker Rocky laced 19-inch Borrani wheel
• New K70 3.5×19-inch front and 4×18-inch rear tires
• Custom side number plates prevent locking up with other racers
• No brakes front or rear
• Bike ran in the Brakeless Class
• This bike was lost for 50 years and was discovered by Rob Talbott of the Talbott Motorcycle Museum
• The bike was passed on to Bultaco racer Robbie Cadwallader, who restored the bike to its original race form

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