1978 R100S thoughts on these bikes

[Junkle]

I am going to go look at a 1978 R100S and I was wondering if anyone here had any tips on this model/year. It has sat for the last 10 years with the occasional start. I suspect it won't start when I get there. The guy admits the mufflers and rear rotor is shot. Is there any way to check the tranny if the bike isn't running?

I figure the inside of the gas tank, the front spring/rear shocks should be checked. Also it probably wouldn't hurt if I could get a look at the rear splines. Other than that I'm not quite sure what to look for on these (I don't mind doing some work, but I don't want to buy something that has an enormous bill with getting it on the road).

Thoughts? Advice?

I really wish the 70's BMW hadn't gone up so much recently as I'm looking for a cheap one for a cargo hack.

Thanks,

j.

[lkchris]

Nothing more expensive than a cheap BMW.

[flash412]

Nothing more expensive than a cheap BMW.+1
(Unless you have a stash of parts for it and do all the work yourself.)

[PAULBACH]

The forum is littered with members who have

bought cheap and paid dear! :violin

[Junkle]

So basically no cheap BMW is worth buying?

I don't expect to find a perfect motorcycle for nothing. I am willing to do as much of the work as I can (and learn about the bike in the process) I was just hoping for ways to look for larger looming bills. I know with used vehicles there are telltale signs of larger issues. I was hoping maybe there were some particular things to look for on one of these bikes.

thanks,

j

P.S. I hope this tone doesn't sound wrong as I am not trying to be argumentative or difficult.

[DougGrosjean]

So basically no cheap BMW is worth buying?

I don't expect to find a perfect motorcycle for nothing. I am willing to do as much of the work as I can (and learn about the bike in the process) I was just hoping for ways to look for larger looming bills. I know with used vehicles there are telltale signs of larger issues. I was hoping maybe there were some particular things to look for on one of these bikes.

thanks,

j

P.S. I hope this tone doesn't sound wrong as I am not trying to be argumentative or difficult.




People are just trying to save you from your own enthusiasm.

I owned a 1978 R100s and loved it. But... I bought mine in nice shape in 1990.

The Good:

Simple design.
Easy to work on.
Maint. parts are available, often in stock around here, usually priced fair.
Many larger parts can be bought used.

The Bad:

Non-maint. parts can be very expensive (mufflers, fuel tank, bodywork, seat).
There can be many issues that you can't see in your inspection (transmission splines, wheel bearings), and will only find out once you have it on the road again.


If it's been sitting a long time, and many non-maintenance parts are rotted / rusted, then the money you'll need to spend to make it usable will be a pretty good-sized pile, even if you do all the work yourself.

If you have to take it to the dealer for a lot of the work, you'll very quickly have far more in it than it's worth. And you *may* have a hard time finding a dealer that will even touch / work on such a tired-sat-for-years piece.

Most of the bikes I've seen that are as you described, would be a terrible deal even if the seller *gave* the bike to me free.

[Junkle]

Thanks. It's never fun to bust someones bubble and I appreciate you guys being straight with me and talking me back from a potential ledge. I might go look at it, but it seems highly unlikely that it will be worth buying (especially at the asking price).

Sigh.

Thanks again,

j.

P.S. Doug -- When is your book coming out? My wife and I thoroughly enjoyed the sections you read at the Square Route Rally and I keep checking authorhouse for it, but nothing so far.

[DougGrosjean]

Hi J,

FWIW, I still go look at rough bikes because one of them might pan out. Just be careful, and keep in mind what people here have said. I hope we're all wrong, but I'm betting we're not.

Glad to hear you enjoyed the reading(s) at Square Route!

You didn't ask, but have you seen the panoramic of the audience? if not, here you go:

http://i60.photobucket.com/albums/h33/DougGrosjean/Square%20Route%20Rally%20-%202006/AAAA-Audience-SRR.jpg

I don't have an exact date yet; I'd expected the book to be out before SRR. The publisher is in the process of correcting about 2 dozen formatting errors, and I'm expecting the galley / proof for that any day now - it's supposed to be done any day.

Assuming they've corrected the errors I asked them to correct, and not introduced any new ones in the process, the book would go live about 2-3 weeks from the time I give the green light. It'll take me about 3-5 days to read the galley, once it arrives (I can download from the Authorhouse.com site). So at this point, I'm on pins and needles waiting for this 4th galley, and crossing fingers that it's right.

Authorhouse does have a page up about the book:

http://www.authorhouse.com/BookStore/ItemDetail~bookid~32002.aspx

... but no availability date because I haven't approved the galley yet.

That's all I know. Hope it helps!

Best,
Doug Grosjean

[RichardCook]

I bought my 1987 K100RS sight-unseen on eBay from a lawyer in the East. The advantage I had was that the bike had less than 2000 miles on it. I had it delivered and, as soon as I got my license, gingerly rode it to Chicago BMW where I had it inspected.

The master mechanic was very nice and extremely patient with me and told me that it was in pretty good shape but that all the hoses and fluid should be replaced because of the hardening and deterioration that occur with 20 yrs of inactivity. I ageed and this with a few other things got fixed over the next two weeks at a cost of just under $1000. Along with the $5000 I paid for the bike and the $700 I spent to have it shipped, as well as the Aeroflow windshield (which is really wonderful!) I have just a bit over $7000 in the bike.

The bike has been really solid and I now have a just about 1000 miles of my own on it. (I set the trip odometer to zero just before that first ride and haven't touched it since -- I have a nice lifetime BMW mileage counter as this is my first BMW and also my first bike with more than 150cc displacement!) Assuming 40 mpg @ $3/gallon, my average cost has been roughly $7.20/mile, give or take. Although this is very high, it is a nice number because I can cut it approximately in half by riding another thousand miles!

Of course it is probably not typical to get a bike in this condition -- it really was mint and I am grateful to the guy who sold it to me and who was a wonderfully helpful fellow throughout the process. TMYGMV but my bike has been pretty reliable.

4WIW.

Richard "Don't tell the wife any of this or I'll get in real trouble" Cook

[Motorman]

On the other hand buying nearly new or new won't save you money either. You have the higher acquisition cost and the services can be very pricey as well. I was looking at a K1200LT and was told some of the regular services were about $800.00 while it was still in warrantee.

As long as you know what you are buying (running and ridable is ALWAYS better) and are willing to accept that you will spend more than the cash value of the bike YOU want to fix it like you want, go for it. You are doing this for your enjoyment of ownership not as an investment. "Investing" in a motorcycle ranks right up there with those who buy bridges. It's a consumable item and will devalue. If you get fun out of it and enjoy owning / riding it then you are ahead. If you are doing it to make money, I have a slightly used bridge for sale that is a better investment.

[DougGrosjean]

With a new bike, you spend a lot of money on the inital purchase, and not so much on un-planned repairs (assuming no crashes).

With an old bike bought cheap, you spend little on the initial purchase and usually a lot on un-planned repairs (still assuming no crashes).

The real trick is in finding the balance between new and decrepit that your wallet and wrenching ability can afford. And that point is different for everybody.

Doug Grosjean

[Junkle]

Well the goal of this is to spend only a fraction of $7000 (I don' think I could bring myself to spend that much even on a new bike -- I'm cheap). Basically I need to find/fix something relatively cheap for local travel so I will still have the cash to do the sidecar portion of it. The reason I am set on trying to find an airhead in the 70's to hack is because I have a 1974 R90 with a sidecar. The theory is that if I learn to fix one I will be learning to fix the other.

Of course theories are often very dangerous things . . .

j.

[DougGrosjean]

Well the goal of this is to spend only a fraction of $7000 (I don' think I could bring myself to spend that much even on a new bike -- I'm cheap). Basically I need to find/fix something relatively cheap for local travel so I will still have the cash to do the sidecar portion of it. The reason I am set on trying to find an airhead in the 70's to hack is because I have a 1974 R90 with a sidecar. The theory is that if I learn to fix one I will be learning to fix the other.

That all makes sense.

I don't know what older Airheads are running these days, or I could advise better. Last time I looked, it seemed Airheads had bottomed out on price and were rising.

I can only say that my 1992 R100gs with 40k miles on it was about $4k, then over time has required a couple more money transfusions (rear shock, and the swingarm bearings went out after a beating on CO 4wd trails).

If you're somewhat mechanically inclined, and it sounds like you are, one really helpful thing on an older unit is the supplies of used BMW parts.

By all means, take a look at the one you've found. But especially if it doesn't run, it's an unknown quantity.

[nhlkats]

The forum is littered with members who have
bought cheap and paid dear! :violin
thats me except mine wasnt cheap! but, on the other hand, education is worth something, and i have learned a lot (for instance: dont buy cheap bmws)
:)

[Polarbear]

You've already got some 70's experience with your older one and the old ones are a ton easier to fix than the newer ones!!! I've done both new and old, as most here have done. I have a '78 R100/7 I bought new and would never consider selling it. It is, without a doubt, one of Beemers better ideas in the last 30 years. The '78 has a lot going for it, even by todays standards. Reliability! My newer model BMW's have none of this, or as much! You may spend some to get it going, but you'll have a good machine for your $$$ spent. Don't be scared off by naysayers, of which many may never know a good thing if they saw it...It flows both ways. Sometimes we get real lucky. Randy13233 :thumb

[Braddog]

I won't tell you to buy the bike. That's your decision.

In the last 6 years, I've bought 2 '77 R100's, one RS and one S in RS clothing. These were my first and only BMW's. Both ran great when I bought them, both were supposed to have been meticulously maintained, and not much required from me. Both were quite reasonable.

What Flash and Kent said is very true. Both of these bikes have required some major repair, i.e. final drive, clutch, tranny, etc. Some of the work and upgrades I did myself, some I took to a local shop. The reason I sunk the money into them is that I really enjoy these motorcycles, I plan to keep them for awhile because they meet my needs, and frankly, I may as well ride them as dump them. I mean, what are you going to do with a motorcycle that you own that needs attention? Junk it? Part it out? Or fix it? I chose fix it. Will I recoup my investment? I don't think so, since I paid someone else to do some of the repairs. Like Flash said, if you have access to parts, and will do the work yourself, then that's a huge advantage.

At this particular stage of my life, time is my most valuable resource. Time means more to me than cash, so I feel I can part with some cash to fix my motorcycles so I can use my time doing other things.

There's also a certain aspect of a "labor of love." A '78 R100S would be a nice bike to have. If you put a bunch of your own time learning and fixing up a machine like this, you'll want to keep it and ride. You most likely wouldn't be able to recoup your investment anyway.

[rinty]

Junkle:

Resurrecting a used bike that has been parked for a long time can be one of the toughest assignments around, due to the issues resulting from fuel gumming. And many owners don't drain the fuel when the bike goes into storage. On the other hand an airhead has a very simple fuel delivery system, so rebuilding the carbs and petcocks isn't going to be a big ticket item. Concerning the transmission, if you can't check it by riding it, you may want to take a pass on this particular bike unless the owner is someone you feel you can trust.
I have been in the process of selling an airhead for months now, (it looks like I have a buyer now) and I have spent literally hours on the phone with interested people, as they try to find out more about the bike, and probably about me. There is a good supply of them out there, but they're located all over the place.
You said you just wanted something to use as a cargo mule, and maybe you should be looking at one of the '80 to '84 models, which have a number of technical improvements over the '70's airheads, and may cost less as well.

Rinty

[DarrylRi]

A big reason to go for an '81-up model is to get the Nikasil cylinders and electronic ignition. The cylinders last much, much longer than the old iron-sleeved cylinders, which typically need a rebore in the 50-70k mile range. The electronic ignition is reliable and eliminates fiddling with points and condensors, which are essentially unknown technology to today's mechanics.

OTOH, the 81-84 bikes have valve recession problems because BMW made a preemptive change to the valve seat material, aticipating lead free gas. If the bike hasn't had a valve job that included replacing the seats in the head then you could be looking at this down the line, and it's a job that most garage mechanics are not prepared to tackle.

If you can step up to the '85-up monolever bikes, this problem is eliminated and you get a more modern rear suspension, too. I put 92k miles on an '85 R80 and had a grand time on it....

[rinty]

I think the '80 to '84's were the best of the bunch. In addition to getting the Nickasil cylinders, you get:

half a litre more oil capacity
the light weight flywheel
direct oiling to the other main bearing
the shock absorbed drive shaft

Admittedly, the compression ratios were reduced to 8.2:1 in 1980, but when you do the valve seat upgrade work, you can skim .030 off the heads and this will get the compression ratio back up to 8.8:1.

The main concern I would have with the later boxers was the much reduced fuel capacity (by one U.S. gallon) to accomodate the extra electronic stuff under the tank. And some people don't like the smaller 32mm carbs, but they actually improved midrange acceleration a bit.

Rinty

[PhilR807]

I bought a '78 R80/7 4 years ago for $2100 and have spent another $2200 for everything (except gas, insurance and the cool riding jacket) and ridden 20,000 + miles. I have traveled 500+ miles to a rally. The biggest expense has been a $500 valve job. And tires.

If you buy an old bike get your hands dirty. Change the oil/all fluids. Set the valves. Lube the splines. Knowing that you can stop by the side of the road and fix (or get some help from the anonymous book) is priceless, and will get you more blank stares from your co-workers when you tell them that you are planning a trip on a 20+ year-old bike.

Remember when the big one hits and fries all the electronic ignitions, your points will still work!

[James.A]

My friend Potter bought a derelict R75/6 for $1200 and spent almost another thousand getting it sorted out. He now owns a great running bike for $2200. He elected to retro-fit a /5 drum front rather than suffer the expense of all new hydraulic brake parts. Your prospective R100S will almost certainly take you to the bank on brakes. You'll need tires and a complete fluid change and a carb re-build and a tank cleaning and creaming. You need to get the bike at a price that let's you budget around $1500 for re-hab, doing the work yourself, and still be happy. If the motor is not siezed, make the seller pull the plugs and have a look inside the holes with a flashlight. While the plugs are out, use the real wheel to spin the drive train and engage all the gears. This will give you a sense of the condition of the transmission. Late 70's gearboxes are pretty darn good devices.

Oh, by the way, happy birthday.

[pcu9000]

I have a toral of five Airheads including two 70s airheads, a '78/7 and a '77 100s and will tell you that any money you spend on this bike will be well spent.

These bikes are simply great to ride. They're not too heavy and also have more than adequate power. True it's going to need some tlc but trust me, it'll be worth it and prices of these bikes are starting to climb.

Parts are easily located.

Good luck! :)

[Junkle]

Thanks for all of the advice, but if you reread my posts there is a reason I am looking for a bike in the years/sizes I mentioned.

I didn't bother to look at the bike that started this post but it all worked out as I bought a much better bike for only a few dollars more on saturday (and road it home). She ain't purty, but boy did she run good. :)

j

[DougGrosjean]

Thanks for all of the advice, but if you reread my posts there is a reason I am looking for a bike in the years/sizes I mentioned.

I didn't bother to look at the bike that started this post but it all worked out as I bought a much better bike for only a few dollars more on saturday (and road it home). She ain't purty, but boy did she run good. :)

j

Congrats, glad to hear it all worked out in the end.

Almost always does, right? Funny how that works.

[jmerlino]

As a pure value proposition, an old Beemer isn't really that great a deal. On the other hand, if you love the bikes, they're very rewarding. Other people on this thread have detailed the pitfalls, but I will say that once you've got the thing running well, it's a pure joy.

[James.A]

Joe, you are absolutely correct if value is reduced to pure dollars and cents. However, the value of owning a well sorted airhead in terms of the riders experience in all facets of ownership eclipses the purely monetary consideration. I'd like to think that you would agree on that level. Hell, in Illinois, there are often more non-airheads at Airhead Tech days. What is it about these bikes that inspires such intense owner loyalty amongst owners and former owners, and owners who now ride other machines? Is it the bikes, or the people?

[phil]

In May I purchased a 1972 75/5 for $2100.00. As of today I have another $2000.00 in parts orig seat,pipes,battery covers,fork gators etc. The bike is now mostly torn apart for paint. I know I will have alot more than its worth when I am finished. I have made a decision I am going to keep this bike for alot of years. I searched high and low for a clean 75/5 they are getting harder to come by IMO. The folks here are right find an airhead that needs some work. In the long run It will be a keeper. I just recently sold a 2006 1200GS. That was the most unreliable bike I have ever owned. These new bikes are way to complicated to work on. I did purchase a new 650GS for riding around town.

[jmerlino]

What is it about these bikes that inspires such intense owner loyalty amongst owners and former owners, and owners who now ride other machines? Is it the bikes, or the people?
Both, I think. I think there's just something really cool about those old bikes. I like the simplicity. There's nothing on that engine that I don't understand, really - even if I may not know it inside and out. And there's just something that feels great and sounds great about the bike when it's running well.

[DougGrosjean]

For me at least, the thing that keeps me around BMW Twins is they're good all-rounders. Easy to work on mostly, mostly comfortable, mostly smooth, mostly reliabl, mostly long-lived, most parts are available and priced reasonably. They run quietly and reliably day after day, not showing too much of the rider's psyche in the process.

They're just practical motorcycles for grownups, those who don't need shiny chrome or lots of noise or fancy paint to enjoy themselves.

[Junkle]

Almost always does, right? Funny how that works.

Yep. Especially when the folks here cautioned me against making a purchase with my heart. Learning to love a piece of equipment is one thing, buying it out of lust is usually a mistake. Sometimes that lesson needs to be put back in our minds when the lust strikes. lol

As a pure value proposition, an old Beemer isn't really that great a deal.

Well I look at my motorcycle as a vehicle first and a hobby second. Nowhere in the equation do I try to consider it as anything else. People who think they are investing in a bike are usually kidding themselves (or someone else) to rationalize buying it. My bike is a useful hobby and as such I expect to lose money on the whole thing (minimizing the loss is also part of the game).

As for airheads . . . I bought one last year with one thought (and the one I just bought had the same reasoning behind buying it). You can get parts for these things and keep them on the road indefinitely. I wanted to get bikes that I could ride ot the grave (and hopefully that will be a long time from now). Sure they'll need some cash spent on them as the bigger items wear out, but they are infinitely (it seems) rebuildable. And now that I have two of the same bike I can always use one for parts if it gets too shot.

j

[pmdave]

I have two airheads, an R75 "toaster", and an R100t with a Ural Sidecar.

I purchased the toaster for a price so low I'm embarrassed to admit it. So, having very little invested, I could afford to do what was needed to unstick the piston, fix the cracked valve cover, replace the main wiring harness, etc. etc. I didn't restore it to "like new" condition, but rather fixed what was needed and replaced some parts with other BMW parts (like the K75 handlebars and /7 mufflers)

By using parts from my shelves, and spending lots of time taking apart and putting together, I probably have no more than $1500 invested. No way would I sell this bike for less than $5000.

The R100 has been overhauled several times in the maybe 250,000 miles of it's life--one component at a time. I bought the bike new in 1980 for around $4500, and I'd guess I have since then bought $4500 worth of parts. What you have to buy depends on your luck. Drop a valve and you're looking (at least) at one new cylinder and piston, one used head, and rebalancing of both pistons. (We're not talking labor here)

I had to chuckle over the phrase "major work" on an airhead. Compared to what BMW is building these days, nothing you can do on an airhead is "major". Yank off the cylinder heads in less than an hour. You can have the final drive on the bench and apart in about 30 minutes. Pull the transmission and lube the splines in maybe 90 minutes--allowing time to sip a cool one and repaint the battery box.

The airhead really lends itself to a winter restoration project. Reshim and repack wheel bearings, replace seals, replace rubber boots, clean electrical terminals, fix the intermittent turn signals, send the heads out for a current spec valve job, order up some Staintune mufflers, replace the brake rotors and pads with EBC, etc. etc.

You'll never be "finished" futzing with an airhead. Next winter you can change all the cables, respoke your wheels with stainless steel spokes, and get the gas tank repainted. A year later you can rebuild the carbs, maybe add alcohol-proof floats and bowls, and maybe treat the old girl to an Omega charging system.

It's an obsession. It's an occupation. It's your offspring. And it's your future ride, because the more you futz with it, the better it gets.

I think this is a good time to buy an airhead, because they are just turning from "old" to "vintage". And since many dealers are no longer working on airheads, that means the spoils go to the home garage mechanic.

Prices? That's strictly between you and the seller, and has little to do with "blue book". The Flea Market in ON is a good reference for what certain models and years are selling for.

The caveat? If you're not willing to get your fingernails dirty, you probably can't afford an airhead.

pmdave

[plexiform]

I made the mistake of selling my 78 r100/7 5 years ago because I needed the money and regretted it ever since. Purchased a 2003 Moto Guzzi Lemans which is a joy to ride and has tons of power and endurance, but I missed the beemer a lot. Just recently acquired a 1988 R100rs with 80K miles on it and it runs great. I anticipate having to spend some money on it every now and then, but I'm just happy to own one again. They are gorgeous bikes and I feel like they are better balanced than any other bike I've ridden. Anyway, just wanted to add my two cents to the "I love Airheads" conversation.

[Motorman]

To my eyes the airhead RT's were simply the best looking bike that BMW has ever put out. The fairing had a very nice wedge shape to it and didn't take up near the room nor cover up the mechanicals as do the current RT's. To me it was simply the best form and function they had achieved.