R80 motor?
R100 motor ? - 200 cc of difference.
For people prepared to accept some small differences - yes. For people after perfection - no. Gap between seat and tank.
You get that difference on washboard - with the engine power on. The paralever is better that as it removes some of the torque reaction from the suspension system. Some people prefer the extra relabnility of the monolever system.

R80 G/s
 

Regarding the Monolever (81-87) vs the Paralever (88-95/97?): Yes the Paralever is better on some surfaces, with the power on. Washboard being one such surface that really brings out the jacking, or stiffening of the rear swingarm. I've had both bikes, and would say that the difference in a stock setup is noticeable but more influenced by the shock. So, Monolever with a good shock is betterthen/ equal to the Paralever with the stock shock.

Reliability/ simplicity: Monolever wins hands down.

The only other issue to consider is tubeless tire fitment. Grant feels this is a significant enough safety issue that he is moving towards fitting his G/S with a paralever to get the tubeless tires, which have less dramatic blowouts if/ when they get punctured. Never experienced a blowout (yet..) with the tubed tires, but it doesn't sound very pleasant.

The 35 liter PD tank from the Monolevers is, in my opinion the nicest looking tank ever mass produced. It is worth paying the extra $1000 that the PD versions tend to sell for, you will have trouble finding a tank for that price. They just don't come up for sale that often. I've heard rumours that you can still order the older PD Tank from BMW, but never had that substantiated. Anyone ever had any luck with this?

Can you not fit tubeless rims on an R80?

Anything is possible - given enought time & money.

However using off the shelf wheels - it is not possible to have tubless wheels on the monoleaver (I think that is what your post is about?). There was a paraleveler (tubless wheels) with an R80 motor .. did not sell well.

I have put the cart before the horse and purchased the BMW R80 PD tank and PD seat. Maybe not the wisest move but I want the R80 PD and decided it may be sometime before one comes up for sale and I could go ahead and buy a regular R80 and add tank and seat and have the same bike. Hopefully, a good R80 will come up for sale soon or If I find and buy a PD, I will sell tank and seat.

PD Tank
 

Good call, the PD tanks are kind of hard to find. You will easily sell it if you find a full PD. Good luck with the R80, there are lots of good ones out there. Old bikes, but fortunately most owners seem to take care of them.

Any thoughts or advice as to whether it would be worth taking this eBay Motors: 1981 BMW R80GS Rolling Chassis & Engine (item 300254601280 end time Sep-09-08 16:28:04 PDT)

and rebuilding into R80 PD model? I already have the tank and seat but would need front and rear fender and then to fix it up mechanically. Price seems a little high. Also, any idea of realistic cost to put in "good" condition for overland trips? Any help appreciated.

Just a very cool bike! Could be a good connection for someone building an R80? :thumbup1:

It’s a very nice idea to build your own bike.
I have no idea if the price is right for USA, I would probably have bought it if it was in Norway:-)

Some info:
Framenumber indicates R80 G/S USA (march -81)
Bodywork missing
Subframe modified, probably has to be modified again to fit panniers
Reflector fork legs missing
Exhaust painted (probably because of rust)
Rear footpegs missing
Toolbox missing
Battery is probably bad
Rear shock is probably bad (for touring)
The bike has the small sump-guard
There are probably some more parts missing

For a front mudguard you have a lot of options, I use some kind of Yamaha mudguard and find it better then the original.
Rear you can get an original or you can fit an Acerbis Baja (or other models).

The wiring looks tidy, but you never know. The bike should be fitted with a Bosch starter which seldom fail (beside it needs cleaning and lube). The charging system should be checked! The coil (if it’s the original grey one) is a weak point and should be changed to a newer one (black).

It’s hard to know how much this will cost or how much time it will take. The best thing would have been to strip it down completely and change/lube all the chassis-bearings and change various seals.
If it has been stored with water in the gear-oil (quite normal) you can expect problems with the gear-box.

There are tons of parts available, new and used, so it’s easy to get parts.

If you want to change the gearing you need to change the bevel-drive, all gear-boxes have the same gear-box ratio. It’s also possible to make fifth gear higher and/or first lower.
If I remember correct you will have 4200 rpm when you drive in 100 km/h (60 mp/h)
It’s easy to rebuild it up to 1070ccm.


If you are prepared for building your own bike and you think the price is right then go for it!

I think you've found your GS expert right here!

Mollydog, I agree. Alibaba, thank you for the info. That is exactly the type of info I was looking for in regards to I am not familiar enough to spot what work needs to be done. The issue with the panniers etc I could never spot at this time. I will keep looking for the right one. I expect to have to do some engine work, upgrade suspension, and upgrade electronis but the less I have to do the better.

I see that you own two Land Rovers so I guess your mechanical skills are more then good enough to keep the airhead running forever :-)

I used to have a series III and I sure learned a lot, interesting car!

Yes, I like the simplicity, sometimes, of the Series and also why the R80 appeals to me. I do not mind starting from scratch on an R80, however, much like the Series, the more work already done by the previous owner the better as the little things begin to add up quick.

The R80GSPD listed on page one seems to be for sale still... and IMHO at $4,500 with the PD tank it is quite a good deal!

1986 BMW R80 G/S - P/D A steal at 4500 OBO

Here's my '81 on a recent ride...

http://i56.photobucket.com/albums/g1...DSC04768-1.jpg

Unfortunately, it is already sold. I like your 81. What type of Panniers do you have and do you like them?