Airhead Powered Roadster Project

[KauaiSlash5]

Aloha. I'm gathering the bits together to build a 4 wheel roadster (think '20's/'30's Bugatti Types) that I plan power with a 1974 R90/6 motor. I want to keep the instrumentation simple and familiar. My daily ride is a '72 Slash 5 Cafe -so I'd like to use the combo speedo/tach unit from the earlier bikes. My question is: Will the R75/5 speedo/tach combo gauge play nice with the later R90/6 motor? I know they switched to separate gauges in '74. How about the sensors and indicators? Thanks in advance for your help! ~Will

[Major Softie]

What kind of rear drive will you be using? The BMW speedos run off the tranny, and have different ratios for different rear drive ratios. Fact is, an electronic speedometer would probably save you a lot of headaches, as they can be programmed/adjusted.

[KauaiSlash5]

Thanks for the reply. I'll be using the complete R90/6 motor & transmission. I haven't yet checked the ratio on the differential I'll be using. I realize adapting the motor & trans to the rear axle will be a challenge -believe it or not, that's what I'm looking forward to! And I know some recalibration will likely be needed.

My main concern is whether the earlier R75/5 headlamp combo gauge is compatible with the later tach and speedo drive cables and various "dummy" indicator sensors/lights found on the '74 R90/6?

[Garnet]

Yes, as far as the cable ends go, you can use a /5 speedo unit on a /6.

[KauaiSlash5]

Thanks for the info Garnet.

BTW, I tried to attach a pic to this post of what I'm hoping to build, but got a message saying "sorry, the board attachment quota has been reached".

[moonbeamerll]

You've got my interest. What wheel/tire setup are you anticipating? Try posting that pic again. Inquiring minds want to know.

[KauaiSlash5]

I'll be building this car on a 1933 Austin 10 chassis. It's a drop I beam chassis with leaf spring suspension all around, 19" wire spoked motorcycle wheels, cable actuated drum brakes, with sidecar tires. The frame is about 10 feet long and 4 feet wide with an X member. It's going to be very low and very light.

Here's a pic to give you guys and idea of what I'm aiming for on this build:

[Sibbo]

A type 35B ? A great model . Here's something you might enjoy too. A Pembleton kit car based on a Citroen 2CV, I'm sure you've seen it before but here we go .

[KauaiSlash5]

Sibbo -
Yes I'm familiar with the Pembleton and like the looks. Unfortunately Citroen 2CV's aren't as easy to find in the states as they once were, and I like my cars front engine rear wheel drive -or better yet mid-engine! But the Pembleton was certainly on of the inspirations for my build. I believe there was one listed on Ebay recently.

Well folks unfortunately my R90/6 motor plans have fallen through, so I am now looking for a complete motor for the project. I would prefer the earlier R90/6 motor with the kicker and 5-speed, but am open to all options. Looking for something that is complete and runs well. I know it's a tall order, but figured I'd ask anyway. I once sold a completely rebuilt '65 BSA Lightning 650 engine -so I know it does happen from time to time

I have a shipper and friends in California, so for now I'm limiting my search to that area. If you have anything or know of something please let me know. Thanks!

[Deleted User 62]

Will (KauaiSlash5) just sent me this video of him and a buddy riding on Kauai. Pretty cool stuff! http://www.youtube.com/watch?v=by08AZIaCug