R100 advice/opinions wanted

[NC Steve]

Let me say up front that I purely love my R65 and plan to keep it forever, God willing.
But, I've also realized it's strengths & weaknesses, and long distance, high speed work isn't it's strong point, so, I'm seriously considering adding an R100 (or the right big Guzzi, but that's another story ) to the garage.
I'm thinking primarily of an RS, although the RTs are more abundant and generally a little cheaper too. I love the RS' fairing & overall styling, and think (maybe incorrectly?) that the slightly leaned-forward riding position might be a little easier on my lower back and butt-bone than the RT's more upright seating. Maybe add some barbacks and wider bars for a compromise? Has anyone here owned or have much time on both and an opinion to offer?

Also, and this came up here somewhere once before, but the earlier twin-shock bikes, thru 1984, spec out at 70 hp and 56 ft lbs with 9.5 to 1 compression ratio, while the later Monos show as sporting 60 ponies and 54 ft lbs, with 8.45:1 compression. Overall performance figures reflect the differences too. Granted, I'm not dreaming of shattering any land speed records with either, mind you, but 10 hp seems like a big loss when you're only working with 70 to begin with. While I'm not looking to rule the stoplight drags on Sat. night, I do want a bike that'll run strong for hours at, say, 80, and not run out of steam at elevation, carrying gear, etc.
 
On paper, I'm leaning toward the 1981 thru 1984 bikes, like I did with my R65, due to the numerous changes BMW introduced in '81. I actually prefer the look of these bikes to the Monos also. But, newer is often better too.
Can anyone say if one series is noticeably stronger than the other, in real world use?
I've also heard that the latter Mono bikes had several mechanical advantages requiring less wrenching than the twin-shockers: true? If so, would or could this  ease maintenance or increase reliability/rideability?

Sorry for the wordiness of this post, but you folks generally have a lot more experience than I do, and I respect everyone's opinions and suggestions. Clean R100s ain't cheap either, and I don't plan to do this but once, hopefully, so I'm trying to take my time, research things, and get the right bike. I figure that if I don't get overcome by lust for a shiny paint job, maybe I can have me a good sturdy workhorse by next Spring.

Thanks very much, for any & all input! [smiley=thumbsup.gif]

[Ed Miller]

No experience, but if I was getting a bigger bike I would want the horse power.  My R65 goes fine at 90 with gear, I don't know if you would go any faster on an R100.  The difference is when I want to pass some slow poke:  an R100 would accelerate better from, say, 65 mph, than my R65 does.  This (stuck behind slow pokes) has been happening to me lately so often that I'm starting to wish for a hundred horse power, just to get around them.

[nhmaf]

I had an 88 R100RT and wish that I had never sold it - the HP/torque curve of
the later models produced slightly smaller peak numbers, but the peaks occurred at
lower RPMs, yielding more usable power on the road.   The lower HP basically keeps
your top speed down to 110-120 mph, but the torque allows for acceptable rollon
performance.    That 88 would run at 75-80 mph all day quite easily.   I hadn't ridden
an 81-84 R100RT to compare it with,  but others have told me that the 88 was a bit smoother,
overall, while running down the road and at realistic RPMs than the earlier bikes...

If I can find another one in good shape, I'll be buying it !

[NC Steve]

Thanks, Mike, that's the kind of good info I'm hoping to get!

Check out this Red Smoke '88 RS I've just found: nice, huh?!!




PS: Don't forget the Rally pics, ok? [smiley=thumbsup.gif]

[dewjantim]

If you want the later model with the performance of the earlier model, just buy the later model and have a set of thin head gaskets installed. They are available on ebay. Should bump compression up to about 9.5:1 and give you lots more grunt and hauling power. Do it yourself, it would take 3-4 hours max (I work slowly). Can be accomplished using only your factory tool kit and a torque wrench. Don't torque those heads to tight, the book only calls for 25-27 ft.lbs. The larger motors also seem to be more robust and will take more punishment and hop-ups that our R65s will tolerate. There are even a few hot-rod pieces still available new or used in the classifieds. Happy beemer buyin', Dew.

[Helix910]

Steve,

I owned a 1980 R100RT. The upright posture was great for me (I have problems with pressure on my hands) and no back or butt discomfort.  Of course it had way more power than I ever needed.  The most amazing thing about it was the way the RT fairing kept the wind and the rain off. Drive it all winter.

The main reason I sold it was that it was a little too tall and heavy for me - I never could relax at a stop. Of course, I miss the Airhead experience, and that is why I've been looking for an R65.

Speaking of that, I finally found one not too far away - I'm in the process of getting the history and condition. I have an appointment to see it on Monday.

Doug in NC

[msbuck]

Steve,

That's a sweet looking ride!  Clean and I love the smoke paint.  Is it nearby?  I have NO experience on the R100s, so I can't help there... I have been a passenger on a R80RT.  It was comfortable enough, but I've always been partial to the RS style myself.

Doug,  keep us posted on the R65 acquisition possibility.  Would love to hear about it.

[dewjantim]

I had a 1000RS once. Traded a K bike for it and a lot of boot. Ended up putting all the extra money in the RS (it ended up having a bent frame which had to be replaced). It was beautiful, painted pearl white with blue stripes. New tires, odds and ends, even nuts and bolts for the fairing. Took it on an 1800 mile trip to the beach and then to the mountains. It got 63 mpg and ran flawlessly. When I got home noticing that there was a slight leak at the oil pan, I dropped the pan to replace the gasket. Much to my surprise, when the oil pan dropped out came about half of my piston, a couple of rings (in pieces), and the base of my cylinder!!!!! I had ridden all that way on a blown engine which ran superbly, used no oil, and got fantastic gas mileage. Replaced the rings, cylinder, and piston; the bike ran for years without any more problems. Never did get that 60+ mpg again. Probably should have left it alone, hahahaha. Dew.

[NC Steve]

Doug, thanks for your input, and good luck on your latest R65 hunt, and Dew, I'll keep that compression trick in mind: thanks!
Aida, that RS is a sweetie, ain't she?! Found her on ibmwr.org, the last bike on this page, up in Wisconsin:
http://www.ibmwr.org/market/search.php?c1=a&c2=b&c3=s&field=title&target=R100RS&Mode=find

Here's the seller's direct link to lots more pics too. http://mountain.mulehill.com/~vince/R100RS

And, here's another '88 R100, but in an blue RT this time, on Ebay. Another nice one!

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=011&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=320137657115&rd=1,1

I think I still lean toward the RS a bit more though, maybe, kinda sorta...  

[Rob Valdez 79 R65]

If the RS doesn't work out, you could always sell it and buy a RT.


The biggest 4 advantages to a mono bike are:

• less input spline maintenance
• tubeless tire wheels
• no rear splines
• simpler removal of the rear wheel

I, too, like the look of the twin-shock bikes better.
And apparently newer does not alway mean anything.  The Veg, over on Boxerworks, dropped a valve on his 1995 R100R.  It only had 60,000 miles on it.  

[nhmaf]

Ohh, that smoke red RS looks very nice (wipes off bit of drool from mouth)...

If only my customers would pay me on time, but then again, perhaps it is for the best
that I don't have the extra cash on hand right now ...
 

The tubeless tires operation, improved splines, and slightly easier rear wheel
maintenance and definitely corrected valve seat issue are all good pluses
for the monoshockers.   The extra exhaust
plenum/chamber thingie under the transmission can get in the way some,
and you do give up a little top end power, but I personally would have a bit
of a preference for one of them over an 81-84 model.  Though, if I found a good
deal on a well maintained 81-84 model, I might still buy it, even if it did eventually
entail sending the heads out at some point for new valves&seats.

Shopping is the fun part - at least that is what my wife tells me !!
 

[Justin B.]

I have one of each and the later monoshock handles better, gets along with unleaded gas, has better brakes, has true tubeless rims, and requires less maintenance.  Although the later bikes do have a few less HP they are geared a bit shorter so although noticeable it's not drastic.

[NC Steve]

Justin, can you tell us appx. what RPM you're turning in the 75 - 80 mph range, and whether there's much difference between your '81 and '95? You mentioned the shorter gearing in the later bikes, and I'm curious how that translates into road speeds.

Also, any noticeable vibration at that (or really any other) speed?
Again, muchas gracias [smiley=thumbsup.gif]

[Justin B.]

I can't remember exactly but it's only a couple hundred RPM.  I'm wanting to think that the '81 is running abount 3800 RPM at 70 MPH indicated and the '95 about 4k, or a bit more.  The final drive ration of the '95 is 33/11 opposed to the 32/10 for the '81.  As far as vibration, the '95 does feel a bit "buzzier" than the '81 but not to the point of being objectionable.  It could also be that I have the carbs synced better on the '81...

[NC Steve]

Thanks, everyone, for all the great info. This has given me a good, solid starting point.

My feeble mind also realized that, since BMW reintroduced the R100RS in 1988 to calm the screaming hordes left abandoned in 1984, a good point of comparison might be to research the '88 model. So, I've been combing the 'net, mostly Ebay, and have a couple of old cycle mags containing road tests of the "New '88RS" on their way now.
So, we'll see, I guess  :-/ . Of course, still got the Eldolust bad too: I think I need a bigger garage, and bank account too!