- Joined
- Sep 26, 2009
- Messages
- 2,210
Back in the late sixties my mates A10 Rocket would do 140 mph....speed inceasing with more ALE!, from experance with a early jota which would "out poke" a commando ..135 semi prone was my best speedo reading..but i was not the best stream-lined dude...I recon SPEED was real selling power back in the seventie's ..and manufracters played on that.. Frontal resistance /power equal speed...a little guy with tight leathers , and a tail wind..should do well :!: [, quote="pommie john"]
I agree.
My race 750 has 36mm Amals 10.5 compression and an Axtell 5S cam. It makes 60bhp at the rear wheel. With the highest gearing I have it's supposed to be 132 MPH at 7000 and I've seen pretty close to 7000 in top which adds up with the above.
All this talk of 150MPH and even 170 I find very hard to believe. In an aerodynamics textbook I have it says that at 100 MPH if you want to go 5% faster, you need either 5% reduction in drag or 16% increase in power. Think about it, to get from 130MPH (which is a reasonable figure for 70bhp) to 170MPH would take a massive increase in horsepower which is simply not available from a Commando engine.[/quote]
Doug MacRae said:I don't think a Commando with 32mm Amals and 9.5 compression will make 69 hp or go 155mph at Daytona. The Commando I won Daytona on in 2009 actually did make 69 hp at the rear wheel on the dyno and I was clocked at 129 mph by the speed gun there. If you have a big flat airstrip and super tall gearing you could go a lot faster of course.
I agree.
My race 750 has 36mm Amals 10.5 compression and an Axtell 5S cam. It makes 60bhp at the rear wheel. With the highest gearing I have it's supposed to be 132 MPH at 7000 and I've seen pretty close to 7000 in top which adds up with the above.
All this talk of 150MPH and even 170 I find very hard to believe. In an aerodynamics textbook I have it says that at 100 MPH if you want to go 5% faster, you need either 5% reduction in drag or 16% increase in power. Think about it, to get from 130MPH (which is a reasonable figure for 70bhp) to 170MPH would take a massive increase in horsepower which is simply not available from a Commando engine.[/quote]