Restoring a 1973 BMW R75/5 Motorcycle

September 16, 2007

Bags make it complete

Filed under: 1973, airhead, BMW, BMW motorcycle, motorcycle, motorcycle restoration, R75, R75/5 — Penforhire @ 2:20 pm

So I’m out riding around still doing the whack-a-mole game with mechanical gremlins and I find myself on a major freeway (that’s toll-free highway to you who don’t live in CA). I’m humming along just fine around 65 MPH and I’m starting to relax and take in the scenery. All of a sudden I feel a small thump on my right shin. I look down but I don’t see anything. And everything is still humming along without a glitch. That means nothing off my carb, right? Hmm, large juicy bug? Nope, when I pull over later —


Yep, gorilla snot failure. Well, technically not snot failure. The adhesive is gripping the tank’s paint so fiercely that if I pull on it bits of paint come off with it. I know why this happened. In order to restore my old sun-faded rubber tank panels I soaked them in “Formula 2001” or some similar plastic dressing for months. I tried to protect the backside but I’m sure I failed. So some of this dressing was either on the surface or worked up from inside the rubber and ruined adhesion. I have no idea where, exactly, I lost that panel or I’d go hunting along the freeway. Fortunately these are only $20-something parts and a replacement is on the way from Bob’s.

I’ve only had one really strange thing happen so far. I had fully shifted into second gear after turning a corner on the street. I was then accelerating when the tranny slipped completely into neutral. I don’t know if it was a “false” position or if the neutral indicator was lit. I was too busy throttling down and deciding what to do in traffic with no go. I upshifted and I think I got 3rd gear though I would not bet a large sum on it. Could have been 2nd, I was a touch rattled. But after that shift all was fine. Very strange.

Now that I’m thinking of travelling further on this machine I’m glad my bags arrived. These are semi-replicas of the old Krauser bags, produced today by Hepco & Becker.



They fit onto my stock BMW frames with just a little extra grunting. The right side bag is very tight to the rear turn signal. My right rack loop seems to be shifted to the rear or bent back an 1/4″ or so. This is only significant because the seat will not open completely with the bag in place. I just have to plan on gentle prying each time I want to remove the bag. I say these are semi-replicas because they are better than the originals. They are a little deeper, supposedly will accomodate a full-face helmet, and the latches are improved. There is probably no need to wrap a bungee around them to prevent ’em from flying open on the road.

I had them up to 75 MPH with one bag loaded with about 7 lbs of stuff and no new instability detected. I am very pleased with them. I am the “be prepared” type and that means I feel more secure hauling around a bag or more of crap like tire repair kit, 12 V inflator, flashlight, fuses, full-size tools, first aid kit, GPS, electric jacket liner, water, protein bars, and the like. I know, laugh at me. But I’m usually the guy who pulls out the widget needed to keep me or my riding buddies going.

I added one more long distance touch. I showed you the Throttle Rocker before. While I really like that device, the stock BMW grip length is such that it interferes more with manipulating the front brake than on my FJR. Not only is the FJR grip much longer but I only need a couple of fingers to stop the FJR. I need a full-hand grip to stop the R75. Well, many years of BMW airheads come with a sort of cruise control, a screw with a nylon insert that applies friction to throttle rotation. It is most useful for tune ups or cold warm-up in the garage because it is difficult to manipulate on the move. I stumbled across the perfect solution while searching the 5 United board for distance-riding complaints, the Schneider Flip-a-Lever (see ). It screws in place of the stock set-screw and provides a toggled friction lock, very similar to the Vista Cruise, NEP lock, and similar friction-based cruise controls.


I’m holding the original set-screw for comparison. Here is the lever cammed over into a “lock” position.


The friction applied can be easily overcome with twist of the wrist. There is enough cam that there is zero drag in the “off” position.

I have one more improvement on the way, reduced-strength throttle springs advertised in Airmail (Airhead Beemers Club newsletter). This fellow claims 25-35% reduction in force and for $10 I’m trying ’em. I know my throttle complaint is spring-based because if I twist to full throttle and release the grip it snaps back to idle instantly. This is not a cable or gear friction issue.

My favorite Marsee Rocket 11 liter expanding magnetic tank bag seems to fit fine on the R75. I need the map pocket for route instructions. Joe, are you ready for a Slow Ride (cue Foghat’s music)? There is a new poker run at the end of the month to benefit Guide Dogs of America put on by the Golden State Glendale H.O.G. Chapter (see ). If the hogs can ride it my little R75 can make it!



  1. Can you tell me where you ordered your replica saddlebags by Hepco & Becker?

    Comment by Todd — May 19, 2008 @ 12:16 am

  2. I’m pretty sure I got ’em from Bob’s BMW. Maybe not the cheapest source but was a reliable vendor during my resto.

    Comment by penforhire — May 19, 2008 @ 6:58 am


    Comment by PETER — September 3, 2008 @ 6:16 am

  4. Peter, that’s a bummer! I ordered mine directly. Check around the BMW owners sites and maybe your local BMW dealers. No idea why the site is off-line.

    I still like mine!

    Comment by Penforhire — September 5, 2008 @ 10:06 am

  5. Dear Peter,

    I have restored my 75/6 and have just received a set of new hepco sidecases thru my local bmw dealer. however, they do not fit the original latches (seatbelt type) on the mounting frame, which were used with original krauser cases which i want to replace as they havent aged too well. did u order the hepco latches as well, and do you mind taking a photo of the mounts with the cases off the bike? i have ordered some latches thru the net yet i am not sure if that will work or not, so your feedback would be greatly appreciated. great work btw.thanks!

    Comment by Bojan — July 21, 2009 @ 12:25 pm

    • Hello Bojan. If you look back a page in the blog you will see some whole-bike photos with the bags off, showing the frames. I reused the frames that were on the bike, just blasted & powdercoated them for cosmetics. IIRC, Bob’s BMW knows about the frame issues and sells frames if you need them.

      Comment by Penforhire — July 21, 2009 @ 2:10 pm

  6. I’m restoring an R75/5 and the wiring is driving me crazy! Can anybody help me?

    Comment by Matt — October 9, 2009 @ 1:55 pm

  7. Hi Matt, as I noted in the blog somewhere, I thought the Haynes manual had the easiest-to-read schematic. You just have to be systematic. Identify each wire, put a tape label on it, maybe highlight it on a copy of the schematic so you know you already identified it. Even then I managed to screw up the starter relay wires (couldn’t read the terminal ID marks) but that’s the way.

    Comment by Penforhire — October 12, 2009 @ 8:14 am

  8. Tried out the K series enjoyed he 750 3 cylinder found the 1000 a bit of a brick.. Had a 1975 BMW R90S with the cockpit fairing. Traded it for a kawasaki (young and stupid at the time) now wished I had hung on to it, what a classic.

    Comment by dave-d — December 12, 2009 @ 3:43 am

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