R100RS - any difference in mpg?

[ohiorider]

I've been riding my 1991 R100GS since 1991. She now has 111,000 on the odometer. A recent carb rebuild boosted average mileage from high 30's into low 40s. My question ..... does the fairing system on the R100RS improve mileage? It certainly looks more aerodynamic than my GS. Is it possible for any of the old airhead RS's, especially those with 32mm Bings, to come close to 50mpg?

Bob

 

[boxerkuh]

I have never heard of an Airhead getting close to 50 mpg. I have an RS fairing on mine and it is only a 800 and I am happy with high 30's or low 40's. I believe that the state of tune does matter, but more than anything how hard/fast/type of riding you do that dictates the mileage. But the Airheads have never been know to get great on mileage, especially when you go over 80mph, I have always considered them very thirsty. If you want a BMW with great mileage you need to get F 650 or the F 800. My food for thought anyway...

 

[donbmw]

On my 75 R90/6 with an RS fairing I get around 45 mpg. One time on the Blue Ridge Park Way after being stopped for speeding I was getting more than 50 miles to the gallon.

Don

 

[lkchris]

I've been riding my 1991 R100GS since 1991. She now has 111,000 on the odometer. A recent carb rebuild boosted average mileage from high 30's into low 40s. My question ..... does the fairing system on the R100RS improve mileage? It certainly looks more aerodynamic than my GS. Is it possible for any of the old airhead RS's, especially those with 32mm Bings, to come close to 50mpg?

Indeed the fairing improves mileage, especially of course as speed increases.

So does the higher rear end ratio of the RS, as the motor runs slower at same speed.

I've achieved 50 mpg on my '84 RS bought new, but that was either in mountain driving or (bad memory) observing 55 mph national speed limit.

Yes, the fairing helps a lot, but don't expect better mileage from 32mm versus 40mm carb bikes. Reason is the latter usually have the higher rear end gearing and that makes the biggest difference. R100RT, for example, consistently returns better fuel economy than R80RT.

 

[Rinty]

difference in mpg

Bill Stermer's book on the RS has a table showing aerodynamic efficiencies over a naked R 100, and it's significant.

I'll post the number later.

But, as mentioned above, there are other variables that affect mileage.

Rinty

 

[78goldie]

I have a 78 RS and almost always average 45-47 MPG. I try to stay away from superslab so most of that is twisties in the mountains of Colorado.

 

[535IS]

I have a 78 RS and almost always average 45-47 MPG. I try to stay away from superslab so most of that is twisties in the mountains of Colorado.

I get into the mid 40s with my '78.

 

[bikerfish1100]

fwiw, i own a garage door that is more aerodynamic than a GS.

i routinely got mid-40's on my dual-plugged, big-piped '78RS. I once got 62 mpg on a run thru some Cali mountains, where i couldn't find my way out of 3rd gear.

of course, i can get a pretty consistent 50 mpg on my 2001 R11S; if i can keep the speeds near to the legal limit, and don't see any stop-n-go action.

 

[TGHSMITH]

most 78 r100rs's came with a taller final drive, leaned out with leaded premium my 78 pulled 48-50 mpg most of the time, my 83rs gets around 45 my wifes r100t with a clipped windshield on a vetter windjammer pulls abot 42 to 43

 

[radar41]

Older RS mileage

My question ..... does the fairing system on the R100RS improve mileage? It certainly looks more aerodynamic than my GS. Is it possible for any of the old airhead RS's, especially those with 32mm Bings, to come close to 50mpg?

Bob

Bob,

Spent the last two days riding my 84 R100RS in the mountians west of Denver, mileage was 45 - 48 mpg. A lot of that time in 2nd, 3rd, and 4th gear @ 3 - 5 K rpm,(love the "twisties" . Mine is tuned as best I can get it (float levels, valves, timing, carb sync, tire pressure, Conti-Tours) and she generally gets good mileage. Can't answer for other RS pilots.

 

[ohiorider]

Thanks to all for your input

I will ultimately own another airhead. I've done the K bike thing (owned a bunch of the flopped over fours and one triple) and have owned two oilheads. I cannot help myself ..... I simply love riding the airhead engine. Maybe it's the fact that 60hp and I get along well together, and neither one of us can do anything too outlandish!

Bob

 

[radar41]

Past/Future Airhead owner?

I will ultimately own another airhead. I simply love riding the airhead engine. Maybe it's the fact that 60hp and I get along well together, and neither one of us can do anything too outlandish!

Bob

Bob,

Check "Craigs List" for Colorado, there are lots of nice Airheads out here. One of our club members (BMWCC) found a NICE late model RS with 109,000 miles. I couldn't believe how clean it was, belonged to an Aircraft mechanic - it was spotless with 109K on the clock & runs like an Airhead should!

We welcome all former Airhead owners back into the "fold"

 

[ohiorider]

Bob,

Check "Craigs List" for Colorado, there are lots of nice Airheads out here. One of our club members (BMWCC) found a NICE late model RS with 109,000 miles. I couldn't believe how clean it was, belonged to an Aircraft mechanic - it was spotless with 109K on the clock & runs like an Airhead should!

We welcome all former Airhead owners back into the "fold"

Radar, I'm still an Airhead rider. The old GS is about to head out to Gillette, WY within the next 4 weeks. Here's a pix of the old gal when she was a youngster with only 90,000 on the clock. This pix (actually a screen capture from a Hi8 Video) was taken in mid-June, 2005, very near Moab, Utah.

http://s115.photobucket.com/albums/...o Utah - 2005/?action=view&current=Slide8.jpg

Bob

 

[tuber1]

my '81 RS could get mid 40 mpg, riding solo with small bit of gear, and riding conservative. Some of the older bikes might get more, but some owners dropped the carb needles at the expense of high(er) engine temps.
Comparatively, my '83 with an 'S' fairing got close to the same mileage,
Alot of factors to consider, wind, temps, road surface, traffic, etc