R80 special build

[AnotherGSGSGS]

Okay so the 100,000km para went to a new home and has had a light refurb and looks great much to my delight. It was too complete and original to do what I wanted with it.

So, doing what I should have done the first time round.

I have an early 80's 800 engine and gearbox, (cheap, very cheap) with light flywheel I believe.

The immediate plan is a mono swingarm mated to a k75 final drive giving disc brake rear. I use rear brake a lot and just don't like drums.

I know there are probably spline issues, I have the k75 arm and fd already I'd got for something else.

I know there are also offset issues with disc brake rears.

So aside from the drive shift problem will the k75 fd actually mate to a mono lever swingarm?

If yes I will need a monolever arm and drives shaft.

Forks are sorted as is front wheel. Will need a 41mm top and bottom yoke.

I'd quite like a 78'T reg frame and motorworks do have one but not really wanting to pay 500quid for that novelty value.

It's a bare engine and box so will also need 32 bings and exhaust downpipes.

With the exhaust not keen on having a collector box but it seems balance pipes are recommended for best performance if anyone has any downpipes?

 

[Mad Hatter]

I’m in, keep the updates coming

 

[Nin]

Nutter, nice one

Rooney Tune

rooneytune.com

 

[mikeyboy]

I’ve got a twin shock frame,with v5 I think,
Might have a mono swing arm,driveshaft,
Might have yokes,
Call me to remind me to have a looksee in storage units,
As a by the by a mate of mine has a very nice hpn tank if that features in your plans

 

[mikeyboy]

I’ve got some g/s headers and a collector.

 

[mikeyboy]

I’ve also got some 38mm twinshock headers ,seem to recall the ends had been chopped off,
Might be good for a start point

 

[Nin]

I have a mono swing arm - no drive shaft. And heads, barrels, 40mm Bings in case …

 

[The Other PaulG]

Blimey you don’t make life easy! Big respect for even attempting this.

 

[AnotherGSGSGS]

Just to clarify this is the type of swingarm I'm after. https://www.ebay.co.uk/itm/35560736...ars4sBCRfW&var=&widget_ver=artemis&media=COPY

Many thanks Mike I'll ring you Thursday.

This is going to be a slow burner.

My sidecar build is nearly complete now and the husky still needs it's engine sorting so I can get the dolly back.

Thanks Nin, noted. The engine barrels and heads are there.

 

[mikeyboy]

Just to clarify this is the type of swingarm I'm after. https://www.ebay.co.uk/itm/35560736...ars4sBCRfW&var=&widget_ver=artemis&media=COPY

Many thanks Mike I'll ring you Thursday.

This is going to be a slow burner.

My sidecar build is nearly complete now and the husky still needs it's engine sorting so I can get the dolly back.

Thanks Nin, noted. The engine barrels and heads are there.

No prob,I’ll have a rummage,
In any case, if there is anything of use,it would be worth your while whilst visiting to have a good root around,in the storage areas.(your new forum name could be stig)

 

[Nin]

Just to clarify this is the type of swingarm I'm after. https://www.ebay.co.uk/itm/35560736...ars4sBCRfW&var=&widget_ver=artemis&media=COPY

Many thanks Mike I'll ring you Thursday.

This is going to be a slow burner.

My sidecar build is nearly complete now and the husky still needs it's engine sorting so I can get the dolly back.

Thanks Nin, noted. The engine barrels and heads are there.

 

[mikeyboy]

View attachment 390211

To clarify that’s not an r 80 mono swinging arm,
It’s a g/s one.
Whilst the dimensions are the same,it has the shock mount on it.
Which makes it considerably rarer than a mono arm

 

[mikeyboy]

I’ve also got a billet 75mm swingarm extension block.
If you come over,remember to mention it.
I’ve obviously no idea what you plan to build at this time ,but have loads of stuff you can look through.

 

[AnotherGSGSGS]

Greenlaner/Beer mat. Function purely over form. I quite like the style of the early 80s jap bikes like the DR400.

Single seat.

As I'm hell bent on rear disc brake then that excludes a twin shock as much as I like them.

I'm only 5'10 so not after astronomical ground clearance. The extension block mated to Nins swingarm could give me what I'm after.

The r80 para was a bit low for the rocky terrain I typically ride and smashed the sump guard hard a few times.

Stig, I'll take that......oh of the dump! Totally.

 

[mikeyboy]

FYI
Cognito Moto do a billet rear hub (spoked)conversion for the r100 rs disc/snowflake/twinshock.
Prob not what your looking to achieve,but mebbs worth a looksee

 

[Nin]

Another option would be to go for an R1100GS swing arm & rear wheel. Manu Schad (SWT) makes a conversion kit. With a bit of Mistacat welding you’d get there.

 

[AnotherGSGSGS]

I had thought that Nin but I'm not right keen on paralever trailing arm dangling down. If going that route I've got an 1150gs rear shock doing nothing so I'd just TIG up a frame bracket

But you are right that it's probably easier to be honest to get to a disc rear.

 

[tuftywhite]

Rear discs are over-rated. They only slow you down.

 

[mikeyboy]

I had thought that Nin but I'm not right keen on paralever trailing arm dangling down. If going that route I've got an 1150gs rear shock doing nothing so I'd just TIG up a frame bracket

But you are right that it's probably easier to be honest to get to a disc rear.

Why not use 1200 swinging arm etc,?
Lighter than 11xx stuff

 

[nicholsonj2252]

The rear brake on an airhead is only there to operate the brake light ;-)