United States 50cc championships
|AFM - American Federation of Motorcyclists is a California-based club founded in 1954
had in the sixties a Californian championship involving 50cc bikes
|Roger Davis about the #114 bike pictured:
- Yamaha FS1 engine - The FS-1 was not sold in the US. At that time, I worked for Yamaha, and ordered the engine from Japan.
- Honda CR-110 frame, bought from Little George (George Vukovic). It was modified into a double downtube loop frame by Tom Rightmeyer, mostly to facilitate engine mounting, and stock in all other respects (wheels, brakes, forks, suspension, etc.).
- The tank was a warranty return with a small leak that I repaired. I don't remember what unit it was from. It sat on rubber dampers on the frame.
- The seat was also a warranty return for a paint flaw.
- Engine work was extensive, with a rare aluminum cylinder. I eventually had the cylinder bore coated with molybdenum, which is quite hard and slippery.
- Performance was quite good, especially in acceleration, where I was competitive with lots of the 100s. Top speed was about 85+. I ran the same gearing pretty much everywhere.
- All at about the same time, the cylinder skirt got broken, life got really busy with drag racing, and 50cc racing pretty much went away here, so I never got it back in race form.
Roger Davis 2015.
50cc road racing in United States of America:
|So the 50GP lovers showing up at the tracks with real GP machines was Jewel Hendricks with his own frame and a Kreidler engine, Jim Ahrens on a Jewel Hendricks’ frame and Kreidler engine, some Honda CR110 (not very competitive), an occasional Tomos, and many vintage ItalJets (Minarelli P6 with 5-6 HP). My disappointment came when I realized that with little work, all those ItalJets could have been boosted to at least double their original power. I worked on Doug Stanton’s ItalJet Minarelli P6 and with cylinder porting, intake timing, spark timing, and expansion chamber modification raised the engine performance to almost 12HP. What I’m trying to say is that the class died in my view for lack of technical passion.
When I purchased the Italian bikes, they came with many spare parts. The biggest upset I encountered was about the failure of the primary shaft (Villa’s gear box); that part came late enough, I believe, to discourage Jewel Hendricks from racing for lack of real competitors. When I finally came into racing with my Ringhini, Jewel Hendricks was no longer racing (too bad! I was really looking forward to good racing).
My racing involvement ended when my company transferred me to Michigan.
Franco Garavoglia 2011.