R100 tank on R65 frame

[Snakeoil]

I looked at the fiche and the front mount appears to be the same. But there is no rear mounting shown for the R65 tank.

I was wondering if an R100/R80 type tank (the original R90S design) is a drop in fit on a 1980 R65?

regards,
Rob

[Rob]

Rob,

The front is the same, but the rear is quite different.
On the R65,R80G/S,R80S/T (not sure after those) it is a bail wire that is attached to the tank with a rubber pad on the bail. This goes under the main backbone of the frame. It kind of rolls into place.
The other key elements of the R65 tank are two "L" shaped foam rubber pads that support the rear of the tank from the frame.

Then there is the issue of the R65 tank being shorter than those on the Type 247 bikes. You will have a gap between the rear of the tank and the front of the seat. At least, that is how I remember reading about it.

Don't forget about under-tank considerations. There are two different twin-shock R65 tanks. The first used points, the second used an electronic ignition, and the underneath shapes of the two are quite different. Both are quite different than a Type 247, of course.

[Rob]

Here is a picture.
I outlined the bail in green.
I outlined the rear pads in red.

Click on the picture for high resolution.



I also threw one in their without the lines if that helps.

[Snakeoil]

Thanks for the quick and detailed reply. I am considering an R65 sidecar rig and I have never been a fan of the R65 tank. Would also like to give it a more vintage look.

Bike is an '80 so points unless someone has installed an EI.

I saw that wire bail on the fiche and thought it might be for attaching the tank. But I could not figure out where it went. It's clear now.

Regards,
Rob

[Rob]

To mount a R100 tank on a R65 dual-shock frame, you will need to replicate the rear mount from the R100.

It's been done before. You might check the R65.org forum. It has been done over there.

[Major Softie]

Curious why you've decided that a hack, much heavier than a 2-wheel airhead, would do well with the least powerful and least torquey airhead motor?

I'm not saying it won't work - I've never even had a hack myself - it just seems counter-intuitive. I'm much more used to people going with much more uber-powerful choices, like Snowbum's K1100 rig.