Category: R80 /7

This is the big project that came about when I pulled the transmission to perform what should have been routine maintenance - an input shaft spline lube. Because the input shaft on the orignal transmission was mangled due to a complete lack of maintenance the original transmission was useless. I had to either have the transmission rebuilt with a new input shaft which would cost almost as much as what I paid for the motorcycle in the first place or find a worthy replacement transmission. As the saying goes, the cheapest thing on a Airhead is the rider, so I opted for a replacement transmission. Martindale Motorcycle Works came through with a solid replacement transmission and I spent Saturday getting it prep'd and installed. It was a full day, and the motorcycle isn't 100% done, but the big stuff is done. Many thanks to my friend Rod for his paitent assistance and for Extra Strength Tylenol for helping me recover.

This project was more than just "replacing the transmission." Removing and reinstalling the swingarm/final drive is its own separate pile of work. Maintenance this invasive requires lots of adjusting and readjusting as all the new parts settle in. In addition to all the planned and expected work, I also replaced the clutch cable. I had one on hand and since I had previously replaced the throttle cables it seemed wise to replace this cable "while I'm in there."

The motorcycle of Theseus now has a new clutch assembly. This was very much a "while I'm in there" project but this one actually made sense. One of the assumptions I made when I bought this 48 year old motorcycle was that I would be best served by performing routine maintenance on all key systems. Working front-to-back, I made my way to the middle of the machine and it was time to perform one of the most invasive maintenance tasks required for the these motorcycles - a transmission input shaft spline lube. To perform a spline lube correctly, the transmission has to come out. On a shaft-drive motorcycle that means the back of the motorcycle also has to be removed so it requires a bit of work. There are videos scattered across the Internets showing folks performing this maintenance without fully removing the back half of the motorcycle but I tend to be a rule follower and "doing things the right way" is my maintenance battle cry. So, the back of the motorcycle was removed so I could do it right. And that's how I said another of my battle cries out loud - "while I'm in there..."

With the swingarm and final drive removed I pulled the transmission out to discover a mangled input shaft. Resolving this is an entirely separate story I'll tell later. Given the state of the transmission input shaft and the corresponding poor condition of the clutch mating surface I decided pretty quickly that a new clutch was required. A clutch kit from Bob's Motorcycles, a few extra bits to address a couple of other overdue maintenace items, and my trusty credit card, and I was in hurry-up-and-wait mode. Bob's staff is excellent, shipping was prompt, and several boxes of replacement parts manifested on my front porch. It then became time for wrenches to begin turning clockwise!

With the clutch removed I discovered that a couple of other routine maintenance items also required attention - the rear main seal and the oil pump cover o-ring. The amount of gunk in the bell housing indicated that both seals were beyond their usable life and required replacing. Neither of these replacements are difficult but one must have the parts on hand. I had a spare rear main seal on hand but unfortunately I did not have a replacement o-ring for the oil pump cover. So, a $4 part held up reassembly for an entire week. As you might imagine, I was a bit frustrated due to this inventory oversight. I called my friends at my local BMW dealer to see if they had the missing o-ring in stock but they didn't (which makes total sense - it doesn't make a ton of sense to dedicate inventory space to a part for a 50 year old motorcycle). They were, however, able to order it (and a couple of spares to keep on hand!). The o-rings arrived as pomptly as it would have taken to ship them from an online seller but ordering locally saved me on shipping. With everything finally in-hand, clutch kit assembly began.

Overall the process was straight-forward and completed in about 3 hours - including replacing the rear main seal and the oil pump cover o-ring. A few specialty tools are required, and I watched an instructional video a few times to make sure I got the assembly sequence right, but all-in-all things went well and a fresh clutch kit is installed.

Making progress on the LED light conversion while I wait for more parts for the transmission and clutch replacement. I finalised the mounting of the polished aluminum turn signal housings for the rear (because this motorcycle has a full fairing there's no need to upgrade the plastic turn signal housings as they sit inside the fairing and cannot be seen when installed) and then decided to pull the fairing so I could get at the turn signal releay in the headlight bucket. Lots of effort but the results will be worth it.

In my opinion and experience, one of the biggest sins committed against vintage vehicles is chopping up the wiring. Factory electrical connectors are specific to the factory part - for example the stock turn signal relay is connected to the wiring loom using a very specific l-shaped connector. The installation instuctions included with the replacement LED relay tell the installer to drive the connecting pins out of the factory connector so they can be reconnected to the new relay. There is limited space in the headlight bucket and removing the stock connector will save room but it also means that there is no way to revert the machine back to stock without sourcing a repalcement connector and then grafting it into the existing wiring. Rather than breaking connectors, splicing wires, and generally molesting the factory loom, my approach is to make what I call "jumpers" to connect my mods to my machines. By my definition, a jumper is a short piece of wire with the appropriate connector at each end. Rather than driving the pins out of the stock turn signal relay connector, I cut three short pieces of appropriately-colored wire and crimped on the connectors required to "map" the stock connector to the LED-compatible relay.

I have no intention of reverting back to incandescent lights but, because no one gets out alive, I know I will not be the last owner of any of my motorcyles. I do not want to be THAT previous owner the new owner curses because I irreversibly molested the machine they now own. Taking the extra time to execute these mods in a thoughtful manner, and keeping the stock bits I remove in a container that stays with the machine, is my commitment to the future of these machines.

In keeping with one of my categories of Signature Upgrades - LED Light Upgrades - I've installed a KAT DASH LED instrument cluster light kit. The kit is essentially a replacement for the printed circuit board that powers the stock incandescent bulbs. Remove and disassemble the instrument cluster, remove and replace the stock board, reaseemble, and see the guages much better! This is a very simple upgrade as it requires very little time but the results are great. I knocked this out in just a couple of hours while waiting on other parts.

I've done a bit to this motorcycle but as of this morning I had only added about 200 miles (and that's a guess because I discovered the odometer wasn't working during the shakedown ride). Since then, more work has been done, more miles have been added, and a tough decision has been made. In that order:

For those of you new to vintage BMW motorcycles, these machines do not have a fuel gauge. To know when to stop for fuel before you run out, you need to have a working trip odometer and you have to know the range of the motorcycle. Odometer failure is a common problem with these old BMWs but my friend Brian is familar with the repair process. Super glue and a toothpick to apply it, and the slipped gear is back in place. The odometer and, most importantly, the trip odometer are now in working order. Now to track my mileage while running a few tanks of fuel through the carburetors.

During the shakedown ride I noted a couple of moments of runaway idle. Typically this is due to throttle cable(s) binding due to wear, damage, or both. Upon inspection, I noted the right throttle cable being a bit damaged at the ferrule. A quick dig around in the parts bins and a new pair of throttle cables was discovered. Removing the old ones (one at a time to ensure they went back in the same way they came out), greasing the gear and handle, and gently adjusting the ferrules to eliminate any slack in the housing took the better part of 90 minutes. This task needed to be completed but it took longer than expected and the spline lube still hasn't been completed.

As the sun set last night, I decided expecting a 48 year old motorcycle I barely know to haul me all the way across Kansas, half way across Colorado, and back again would not be my best decision. This is a solid motorcycle and it demonstrates how solid it is each time I ride it, but it just isn't rational to think an unknown motorcycle behind on major maintenance will allow me to complete such a trip, and during the hottest week of the year. With all this in mind I have decided to stay home rather than attend the Top of the Rockies rally.

I still have one big maintenance task to complete - spline lube. Given the bike was sitting for about a decade and behind on all other maintenance, it is safe ot assume that a spline lube has not been performed on schedule. While the back half of the motorcycle is removed I'll also replace what appears to be a faulty neutral safety switch and replace the gear oil. This will make for a full weekend!

After sitting in the corner of the workshop for longer than intended, sitting quietly in the corner of the previous owner's garage since 2018 (that was the date of the last Missouri saftey inspection), and spurred on by an invitation to attend the 2026 Top of the Rockies rally in Paonia Colorado, I decided it was time to breathe life back into the R80 /7. So far I, along with the best friends a guy could ever hope to have, have performed the following maintenance:

• Refreshed the fuel delivery system
• Changed the motor oil to Castrol GTX Classic
• Rebuilt the forks with new springs, seals, bumpers, and oil
• Rebuilt the front brake caliper and replaced the stock rubber hose with a stainless steel hose (which also required fresh brake fluid and a thorough bleed)
• Had new Michelin Road Classic tires (inch size to keep the motorcycle, not the purists, happy!), tubes, and rim strips installed by my new friends at Donnell's Motorcycles (I have yet to set up my tire machine as my new workshop is still in the planning phase)
• Had the machine Missouri state safety inpected (it passed without issue)
• Made it legal to ride (license plate + insurance)

With all these tasks completed, and because it was the second Saturday of the month (my motorcycle "gang" has a long-standing tradition of gathering for lunch on the second Saturday of each month), yesterday (July 11, 2026) was the shakedown ride to see if all this effort made the R80 /7 rideable.

We decided to mix things up a bit and agreed upon Smoked Creations BBQ as our ride destination. Because I didn't know how the machine would perform, I set Google Maps to avoid tolls and highways, and set out for our destination. Louisburg, KS was the half-way point and the friend that instigated this process would be passing through on his way to lunch, so we agreed to meet at Cowboy Coffee Post. The machine performed nearly flawlessly. The only complaints during the first leg of the journey were that he was a bit cold-blooded on startup and at one point I had a bit of a run-away idle, but both are side-effects of a decade of neglect. Neither issue required me to turn around.

The second leg of the ride to went off completely without incident. A straight shot across Kansas Highway 68 on a 48 year old motorcycle with the throttle almost wide open was glorious! The machine was solid and the Luftmeister full fairing made the ride very pleasant. I haven't ridden behind a full fairing for decades but I thoroughly enjoyed the experience and intend to keep the fairing installed. I even have the lowers that go with the fairing. To install the lowers I'll be forced to remove the crash bars but that change can wait until we get closer to the Fall and cooler riding.

Lunch was fantastic, the conversation was fun, educational, and 100% about friendship, the love of being in the wind, and helping friends solve the problems that can arise when one chooses to ride vintage motorcycles. The time around the table was as meanigful and important as the wind therapy we enjoyed getting there.

The ride home was equally uneventful and completed in a single stage. I rode the back roads home, this time because I wanted to, not because I had any doubts about the machine's capabilities. Two-lane blacktops, twisties here-and-there, and the occassional encounter with shade from the mature trees that line the backroads make for my favorite kind of riding. For me, the journey is just as important as the destination and yesterday's journey filled my cup as much as the time with friends. Glorious is the best word to descibe the day!

With all this in mind I have a few tasks to attend to before heading to Top of the Rockies:

• Spline Lube - this is the biggest, and most important maintenance task that needs to be performed. It involves removing the transmission, is an all-day event, a requirement for these vintage machines, but also one that is often overlooked.
• Gear Oil Change - in conjunction with the spline lube I'll replace the gear oil in the transmission, swingarm, and final drive.
• Odometer Fix - the speedometer works (it reads about 10 mph fast, but it works) but the odometer does not. This is a common problem with these machines, the fix is straight-foward, and can for the most part be completed at the workbench. A working trip odometer matters a great deal on a machine with no fuel gauge!
• Inspecting, lubing, adjusting, and possibly replacing throttle cables - the temporary run-away idle is possibly a symptom of sticking or fraying throttle cables. I'll give them a once-over and adjust and lube or replace as necessary.

This list catches up the key maintenance items and puts me one step closer to this machine being ready for coast-to-coast adventures!

The R80 has been on the bubble since I picked it up last year. When I bought it I thought it might be a candidate for a resto-mod and re-sale but I never put that in motion. I've spent time with the machine and have decided it is one of the three motorcycles I'm going to keep in the fleet. It is my favorite model - a /7 (say SLASH SEVEN) but a 1978 instead of a 1977. In spite of not being of my signature year it is a /7, it is fully-faired - I have the lowers but they need to be installed - and it shows under 50,000 miles on the odometer which, in typical Airhead fashion, didn't work when I bought it. As with so may BMWs of this vintage, it has been neglected and is no longer considered to be in reliable running condition. There is nothing singularly wrong with the machine but is is behind on all categories of maintenance and will be well served by servicing and udpating the key systems.

When I bought it the machine ran well but by the time I unloaded if from the trailer it was only running on one cylinder. I thought about what might be going on, thought about starting with a carburetor rebuild, and then noticed that the fuel was pretty dirty. I dumped some fuel system cleaner in, let it sit for a bit, and then the machine started up and ran on both cylinders. The petcocks were clunky and the fuel line was brittle (and not the right kind for an Airhead!) so I figured I'd start by cleaning up fuel delivery. Parts ordered, parts arrived, and then I moved to the new house. Now that I'm sort of settled I throught a motorcycle work day would be just the thing to make this place feel more like home. A couple of the guys joined me, we took a break for lunch at The Courthouse Exhange, and wrapped it all up around 5:00 pm. I still need a couple of things to declare victory (overflow tubing and some fresh, ethanol-free fuel!) but it was a good day well spent.

This machine needs more TLC but then don't we all?