Indians For Guns

Motorcycle lovers, if you had a Ducati superbike, would you borrow it to a self admitted drug addict?

Well, someone gave Hunter S Thompson a "Ducati 900 Campione del Mundo Desmodue Supersport" to test out.
What follows is a pretty amusing read.
I will not post the contents of this report here as it is not family friendly. It is Hunter S Thompson, after all!
It is from around the mid 90's but Ducks are timeless. Today you can buy a used one in decent shape for about $4500 (drool)


the 900ss sp

On my first take-off, I hit second gear and went through the speed limit on a two-lane blacktop highway full of ranch traffic. By the time I went up to third, I was going 75 and the tach was barely above 4000 rpm....

And that's when it got its second wind. From 4000 to 6000 in third will take you from 75 mph to 95 in two seconds - and after that, Bubba, you still have fourth, fifth, and sixth. Ho, ho.

I never got to sixth gear, and I didn't get deep into fifth. This is a shameful admission for a full-bore Cafe Racer, but let me tell you something, old sport: This motorcycle is simply too goddamn fast to ride at speed in any kind of normal road traffic unless you're ready to go straight down the centerline with your nuts on fire and a silent scream in your throat.

The Link

When I was young, I always had the hots for the 450 thumper. I was totally intrigued with the desmo valve gear.

Growing up, I'd read about the wonders of the 50s Mercedes Benz W196 GP racers and the fantastic 300 SLR (that's "SLR," not the plain old "SL" gull wing).

Back in those old days, valve springs were a common point of failure. For instance, rodders doing up a Chevy stove bolt 6 would use Buick Straight 8 valve springs, because they were of higher quality. Increasing rpm levels put greater stress on valve springs, as did ever more aggressive cam profiles needed for high rpm. Desmo arrangements, while complex, seemed like the ticket in the 50s, as shown by the successes of Mercedes Benz racing.

People with more dollars than sense, like Lance Reventlow, sought to copy the desmo formula for success. Reventlow went to Meyer & Drake (who had bought "Offenhauser" from Fred Offenhauser) and had Leo Goossen draw up a desmo Offy for use in Reventlow's Scarab racers. Wonder boys Jim Travers and Frank Coon (the pair behind the legendary Traco engine builders) talked Reventlow out of big bucks to get Offenhauser to build a competitive desmo setup. The cam grinder was not used to grinding reverse cams and botched the job, and Travers and Coon had difficulties in learning to synchronize the cams, so a fair number of bent valves were the result.

Worse yet, the American mastery of power shown by the demonstration of Offenhauser powered racers at Monza in 1957 had reversed by 1960. The new American engine was lacking power, compared to the Europeans, and Reventlow's Scarab chassis didn't handle so well, either.

The desmo system was a dead end. Mercedes Benz dropped it. Old time Indianapolis racer Art Sparks, ever the innovator, developed the S&W spring that was made of vacuum-remelted wire to eliminate impurities and shot-peened to eliminate stress. Overnight, the rationale for the desmo valve system had disappeared, as the new S&W springs lived at the higher rpm and more radical cam grinds of the late 50s.

Ducati had gone with desmo valve gear after WW2 in the 125cc motorcycle class for the same reasons that Mercedes Benz selected it. They mastered the technology and didn't leave it behind when better valve springs became available. Their bikes were beautiful jewels in the Italian tradition of engineering that both "shows and goes," like this 450:



The cams used the aircraft-like shaft and bevel gear drive, light and elegant (no crude chain drive stuff here!):



Letting a barbarian like Hunter Thompson at a Ducati of any kind would be akin to letting the Marquis de Sade loose at a kindergarten. Ugh!

Hurray for Ducati! Wonderful machines!

Another good one, XL. Enjoyed reading Hunter S. Thompson. The Ducati is definitely on my bucket list.

I first came to know of Hunter though the film Fear and Loathing in Las Vegas .


Timmy,

You knowledge of machines is a matter of amazement to me. Can you rebuild engines too?


Best-
Vikram

Vikram wrote:Can you rebuild engines too?

I have done quite a few over the years. Most common: N, Y, F series and 6 cylinder Continental industrial engines. Most exotic: 1956 Harley Davidson KH flathead (my older son has it now). Most recent: High Performance Chrysler 440 for a family barge.

Desmodromic valves are a bit like pocket watches or automatic wrist watches. Now, there are other technologies that can do the job more cheaply and simply, but they are appreciated by folks who enjoy complex designs and fine craftsmanship.