1977 thru 1984 or post-1988 RS?

[ohiorider]

I really like my old GS. But every now and then, I find myself looking through the classifieds for a really nice R100RS. Here's my question(s), and what I think I know about both generations of these bikes:
Question/opinion - which would you prefer .... the older version with slightly more hp, taller gearing, 40mm Bings .............

or.........

The 1988 and newer RS, built on the Monolever chassis, geared lower, with 32mm Bings?

The older version, thru the 1984 Final Edition would appear to be the long-legged bike, with nearly 70hp and taller final drive. What are the downsides to this series, aside from not having a lug nut rear wheel?

The newer version, 1988 thru 1995 has less hp and is geared lower. Is this a noticeable disadvantage when compared to the older generation RS?

From a purely 'available parts' standpoint, my head tells me 'get the 1988 or newer', but my heart says go with the older, larger, probably quicker RS as it was originally intended to be.

Or perhaps I'm dealing with issues so small that it wouldn't make any difference.

Bob

 

[535IS]

From a purely 'available parts' standpoint, my head tells me 'get the 1988 or newer', but my heart says go with the older, larger, probably quicker RS as it was originally intended to be.

The older one is larger? Not that I have ever ridden any other one. Mostly, I just wrote to tell you how mine used to live in Hudson (along the Twinsburg border). But you can't have it ...

 

[ohiorider]

I've got the hounds out already, trying to sniff out that beauty. Near Twinsburg, huh? Nice bike!

When I said larger, it is my understanding that the older twin shock frames were slightly larger overall machines than the Monoshock versions, which were (I think) built on the R80 frame. I know BMW did publish higher hp figures for the older R100RS bikes ..... close to 70hp. I think the Monoshock versions use an engine that is identical in its state of tune to the one in my R100GS, which is rated at 58hp.

Bob

 

[92r100rs]

Bill Stermer's Book has a really good comparison, including side by side riding impressions and reprints of road test data. The conclusion was that the monoshock handled better and was basically as quick due to improved midrange. The older bikes helds a gallon more fuel though, which I miss on my 92 especially since it gets lousy mileage.

 

[lkchris]

There's ZERO parts availability problem with either.

There has NEVER in any year been any difference between an R80 frame and an R100 frame.

Downsides to the older models are need to rebuild cylinder heads to address valve face plastic distortion problem. Even when this is done, these large-valve heads are comparatively weak and more subject to warping. Access to electrical components in the headlight shell is a little difficult. Older models will not handle as well as the newer bikes with much more robust, essentially K-bike suspension.

Downsides to the newer models are styling distortion caused by using 18-in front wheel when fairing was originally designed to match a 19-in wheel. Another downside is tubeless tires. These bikes will also have the Valeo starter weakness and the missing transmission circlip. The improved ease of accessing electrical components is offest by loss of fuel capacity.

 

[keelerb]

Kent, why do you think tubeless tires are a disadvantage?

 

[97077]

Rs

Kent, I wonder why tubeless tires are a disadvantage? I would think if tubeless was better we would still have them on our autos. I have been driving semis for 24 years and tube tires went out a long time ago. I do like the old spoked rims as far as looks but as far as an everyday tire I prefer tubeless. Thanks for your input on the other parts of these great bikes I seem to learn a lot from these threads. Kevin

 

[AnnapolisAirhead]

Kent, I wonder why tubeless tires are a disadvantage? I would think if tubeless was better we would still have them on our autos. ...

Kevin, last I checked my car tires were tubeless. Did ya mean tubed?

 

[97077]

Rs

Sorry, I meant tubeless.

 

[tkpinsc]

I really like my old GS. But every now and then, I find myself looking through the classifieds for a really nice R100RS. Here's my question(s), and what I think I know about both generations of these bikes:
Question/opinion - which would you prefer .... the older version with slightly more hp, taller gearing, 40mm Bings .............

or.........

The 1988 and newer RS, built on the Monolever chassis, geared lower, with 32mm Bings?

The older version, thru the 1984 Final Edition would appear to be the long-legged bike, with nearly 70hp and taller final drive. What are the downsides to this series, aside from not having a lug nut rear wheel?

The newer version, 1988 thru 1995 has less hp and is geared lower. Is this a noticeable disadvantage when compared to the older generation RS?

From a purely 'available parts' standpoint, my head tells me 'get the 1988 or newer', but my heart says go with the older, larger, probably quicker RS as it was originally intended to be.

Or perhaps I'm dealing with issues so small that it wouldn't make any difference.

Bob

First I'd say the differences are not that great and I would shop for value(price vs condition) not years.

If you ride at 4500rpm and higher most of the time the older 70hp motor will feel stronger. At less then 5k the new motor will be making more power.

The c-clip transmission issue is an added cost if it has not been dealt with on the newer bikes and the valve issue is an added cost on the older bikes, about equal in $$.

The newer bikes will handle better if the shocks are in equal condition.

Depending on year of the bike the panniers will be different styles, personal preference here.

18" tubless are an advantage in my book, easier to patch on the road, and 18" front seems easier to find.

The new bikes have ball bearing wheel bearings, and the older have tapered. The balls are easier to maintain as you just replace them, the tapered are a better design for the application but require more maintenance.

I'd miss the extra gallon you give up on the new bikes.

81 and on have better (brembo) brakes, electronic ignition and nickasil cylinders. All advantages to me.

 

[VANZEN]

frames

...There has NEVER in any year been any difference between an R80 frame and an R100 frame.

True in terms of critical dimensions
(i.e. the same frame jig is used for all).
True as a response to:
"... the older twin shock frames were slightly larger overall machines than the Monoshock versions..."
And true if comparing SAME YEAR R80 and R100 frames.

But not true when comparing an R80(or R100) monoshock to twin shock R100 frames...
Changes were made through the years.
Case in point:

Early R100 frames used a 'tube-within-a-tube' double spine oval tube
having greater torsional rigidity and @ twice the weight of that component –
the R80 monoshock and subsequent R100s used a single oval tube.

Early R100 frames used tapered oval front 'downtubes' (from the headstock to the curve before the front engine bolt)
having a greater bending resistence –
The R80 monoshock and subsequent R100s used single diameter round tube.

(not 100% on this one, maybe the change was made before the R100 ...,but)
The earliest R100 frames (may have) used a single horizontal brace between the front down tubes –
Subsequent R100s (and R80s) had two.

And of course, the obvious casting and bracket changes throughout the years,
including shock, subframe, electrical components mountings.

Relative to the original question –
the newer the bike, the better the handling and esp. braking – significantly better as the age discrepancy becomes larger.
Important to consider if the bike is to be ridden.

 

[ohiorider]

Thanks for the input

Thanks to all for your thoughts and facts about which R100RS to shop for. Mine would be a rider, if the bike fits me. The old GS is a wonderful ride, but I've always had a desire to own an RS airhead.

Bob

 

[lkchris]

While clearly tubeless tires are more resistant to losing air when punctured by a nail, they remain a maintenance nightmare for a motorcyclist.

ZERO tire manufacturers approve external plugging for flat repair--it's just a hope and pray you get home solution. These things do not automatically always work for that, either. And, when/if you do get home, it's off to a tire shop because the type patch required isn't feasible to DIY. (Lots of folks live in ignorance of these facts and therefore assume nonexistant advantages.)

Then of course if your flat occurs while riding and you detach the bead from your rim, you're not getting your tire reinflated (unless you put a tube in it). You'll have plenty of trouble getting a tubeless tire inflated in your home workshop, too--shop air being a minimum requirement.

Most of us Airheads have become used to bead seating problems because we pretty much have to mount tubeless-capable tires (with tubes) on our bikes. There are still tube-type tires available in the USA for the G/S, however, and it's a nice memory to be able to so very easily mount those tires--hardly need tools, in fact. Certainly no inflating to 90 psi to get the bead to seat like with snowflakes.

It's also good for Airheads to understand that plenty of tube-type tires are still available--in Europe where it's legally required that tires meeting manufacturer specs be mounted. USA tire distributors do Airheads few favors.

The advantages of tubeless tires are

1. As noted, better resistance to deflation when punctured
and
2. (most important) cheaper for manufacturers to mount at the factory.