ZU. Why a Ducati Diana?

Posted 6/16/2014

When I decided to try road racing I wanted to race in one of the AFM’s small displacement production classes, which were for slightly modified street bikes. Choosing to race a 250cc Ducati Diana in 1972 was, admittedly, an odd choice. It would have been a good choice in 1966, but in 1972 the logical choice was one of the Japanese 250cc bikes, like a Kawasaki A1 Samurai or Suzuki T20. Even a Honda 175 in the 200cc Production class made sense.

I claim extenuating circumstances. I had been working full time for only a year after graduating from the university and discretionary funds were sparse, so I would have to find a cheap used bike. Also I wanted to do the mechanical work on the bike myself. At the time I wasn’t going racing to win; I wanted to learn wrenching skills and have a little fun on the track.

There were other reasons for the Diana that sound embarrassing now, but made sense to me as a punk kid. I didn’t want a 2-stroke; I didn’t understand how they worked and I didn’t like the way they sounded. I could have done a little research and found out, I guess, but I wanted a small 4-stroke. That narrowed the choices quite a bit since it eliminated all the Japanese brands except Honda.

Chain-driven overhead cams frightened me. I understood that to take the top end off the motor the chain would have to be broken, and then re-riveted when the motor was put back together. Never having done it before I didn’t trust myself to do the riveting right and I knew what sort of nasty damage would result when the cam chain broke. That limited the choices even more – all the Hondas were out. It would have to be a push-rod motor or one with gear-driven overhead cams. It was clear from the literature that the Ducati, with its overhead cam driven by a shaft and two pair of bevel gears, would be the most competitive of these. I could take the motor’s top end off and put it back together without breaking and repairing anything — just line up all the dots on the gears. Also the Diana had been a very popular race bike in past years and quite a bit of knowledge about it was still available. I found one that looked pretty tired and dirty but it started, it was all there and the price was right.

The first tear down was pretty interesting. The inside of the bike matched the outside – it was very worn and dirty. I had fun during the winter of 1972 – 1973 tearing the bike apart, inspecting everything, and creating a shopping list of parts to buy. Making the parts list was easy but finding the parts was a challenge. Ducati had introduced its 750 GT twin to the U.S. in 1972 and the smaller single cylinder models were being phased out. Finding a good parts source was a continuing problem, but I did get a bike running by the beginning of the 1973 racing season.

And that’s the how and the why I got started with Ducatis.

First race shot -- the Diana

2 thoughts on “ZU. Why a Ducati Diana?

  1. Kendal Mullins has one that looks similar to your 250 in his garage and has had it for years. I think his is a Monza (with a different tank) but I believe he has the Diana tank too. It is really little but pretty fun to ride as I recall. Ducatis were cool in the day but I loved my 72 Yamaha R5C (350) 2 stroke. I could easily run with a Norton 850 Commando (Bob Westman) on the Sunday Morning Ride up to about 80 mph and it was super easy to take apart and work on. When I sold my R5 it had over 40K miles on it as my daily driver taking me to college after my time in the USAF, and back and forth to Chico where my girlfriend went to school plus the two years of racing in the AFM (with Kendal Mullins as the rider). That was the very first bike in the SGR team.

  2. Hi Paul!
    There’s lots of great memories and history on this site!
    I rode one of the Ducati 250 singles one of the Dimond Dynaflows had for a street bike. Yes a cool machine – something you might find Arthur Fonzarelli on, but for real speed, the two strokes ruled!
    Mike Kauzlarich

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