{"id":41092,"date":"2025-06-16T09:50:30","date_gmt":"2025-06-16T16:50:30","guid":{"rendered":"https:\/\/pindelski.org\/Photography\/?p=41092"},"modified":"2025-06-16T16:34:45","modified_gmt":"2025-06-16T23:34:45","slug":"bmw-r90-6-35-and-50-years-on","status":"publish","type":"post","link":"https:\/\/pindelski.org\/Photography\/2025\/06\/16\/bmw-r90-6-35-and-50-years-on\/","title":{"rendered":"BMW R90\/6 – 35 and 50 years on"},"content":{"rendered":"

Thirty five years of happy wrenching and riding.<\/I><\/p>\n

I became the custodian of my 1975 BMW R90\/6 ‘airhead’ motorcycle 35 years ago today, buying it for $2,000 in Los Angeles from the original owner with just 15,000 miles on the odometer. Ren\u00e9, the wonderful Chilean seller, was returning to the country of his birth and assured me that riding a single track vehicle on local roads was not a prescription for a long life. He also informed me that he had turned down two earlier offers from ‘irresponsible kids’ who would not accord his machine the duty of care it was due. I do not think I have let him down.<\/p>\n

This beautifully made machine, an exemplar of the best mid-twentieth century technology – and not all that much changed from the 1931 original design – is notable for its near total absence of electronic gizmos, a source of considerable joy for this mechanical engineer<\/a>. Any self respecting mech eng will tell you that electricity is the work of the devil. And this is very much an engineer’s dream for the machine is easy to work on, most parts easily accessible with few special tools required. Best of all the machine’s enthusiastic following sees to it that most replacement parts remain available, 30 years after the last airhead left the German assembly line. Yes, there’s more maintenance than with a Honda but reliability is comparable to that of those fabulous Japanese designs.<\/p>\n

What follows is a pictorial history of my time with the bike over the past 35 years. I continue to ride it regularly.<\/p>\n


\n
\nJune 16, 1990. Accepting delivery in Encino, CA from
\nthe first owner, Ren\u00e9 Francisco Lama.<\/I><\/p>\n


\nAt the fabled Rock Store in Malibu in 1990.<\/I><\/p>\n


\nReady for touring with bags and a small windshield.
\nThe original caf\u00e9 fairing broke when the bike fell over
\nin my Encino garage during the Northridge earthquake,
\nJanuary 17, 1994, the only time it has been down.<\/I><\/p>\n


\nManufactured in October 1974, the bike was sold by
\nBob Brown’s Motorworks in Pomona to the first owner in 1975.<\/I><\/p>\n


\nThe motor is a simple two valve pushrod design.<\/I><\/p>\n


\nEngine maintenance is easy owing to the horizontally
\nmounted ‘boxer’ cylinders. The valve cover and valve
\nhead have been removed here.<\/I><\/p>\n


\nResealing the cylinder with new gaskets is a simple task.<\/I><\/p>\n


\nWith the piston removed the con rod is held safely
\nin place with a cable tie. Nicks on the base gasket mounting
\nsurface are not a good idea. The rubber pushrod seals
\nare replaced at the same time – they harden with
\nage and heat and leak.<\/I><\/p>\n


\nSpaghetti junction. Not BMW’s proudest moment.
\nThe wiring meets up with a small distribution board
\nin the head shell<\/I><\/p>\n


\nThe stock Bosch starter motor is awful, struggling to
\nturn a cold engine. After having it rebuilt twice over
\nthe years I replaced it with a Toyota truck starter with
\nan adapted Bendix. Twice the power, half the weight and
\ncurrent draw. The bike’s modular design means that the
\nstarter can be removed in under 15 minutes.<\/I><\/p>\n


\n Look hard enough and you can still find original German
\nBosch copper spark plugs. That’s all the bike needs in
\nthe ignition department. And ignition timing is 100%
\nmechanical, no electronics. <\/I><\/p>\n


\nA collection of metric fasteners is essential.<\/I><\/p>\n


\nBack in the day batteries came filled with liquid acid, which
\nwould inevitably leak, corroding the battery tray.
\nThe tray has been removed, wire brushed and repainted here.
\nModern gel cell batteries do not leak, so this is a lifetime fix.<\/I><\/p>\n


\nWell, I do have one electronic part in the bike. Here’s
\nthe daylight sensor for the Kisan headlight modulator which
\nflashes the headlight in daytime riding, enhancing the rider’s
\nvisibility to motorists focused on their cell phones. The
\nthree position steering damper is below.<\/I><\/p>\n


\nOver the years I have replaced most of the steel fasteners
\nwith stainless ones.<\/I><\/p>\n


\nA rare failure – the choke cable toothed follower snapped
\nrendering the choke inoperative on one side. A fellow airhead
\nkindly gave me the replacement part which is NLA from BMW.
\nMagura could learn from Rolex when it comes to engraving.<\/I><\/p>\n


\nThe bike came with the smaller 18 liter tank,
\nbeautifully pinstriped by the ladies in Berlin.
\nThe QD trunk is by Givi of Italy, and holds a full face helmet.<\/I><\/p>\n


\nA few years ago I finally got my beaten up 22 liter larger
\ntank refurbished and the pin striping, done in
\nScottsdale, is beyond perfect. I think it
\nlooks far better than the small tank.<\/I><\/p>\n


\nWay ahead of its time, the largely modular design makes
\naccessing most assemblies easy. Here the rear wheel,
\ndriven by a shaft – no chains here – has been removed
\nfor tire replacement. Sadly the wheels require
\ntubed tires, far less safe than modern tubeless ones.
\nThe shocks are aftermarket Konis, superior to
\nthe stock ones, and recently rebuilt.<\/I><\/p>\n


\nThe brake light sensor is a simple pressure switch.
\nHere I am replacing it as it failed after 30 years.<\/I><\/p>\n


\nDuring baking Scottsdale summers I kept the bike indoors
\nto avoid premature rotting of rubber parts. Eventually
\nI insulated and air conditioned the garage to make for
\nbetter summer storage.<\/I><\/p>\n


\nAfter 30 years the saddle foam was shot and the vinyl
\nseat cover was cracking. New foam from the Fatherland
\non the left.<\/I><\/p>\n


\nNew seat cover installed over new foam
\nA very time consuming job, but very satisfying, and
\neasier on the bottom to boot!<\/I><\/p>\n


\nWhile the stock tool kit is excellent the pliers
\nare poor quality. A superb pair of Knipex adjustable
\npliers<\/a> does the trick far better. The cylinder on
\na chain emulates TDC when adjusting the mechanical points
\nignition when installed on the nose of the cam.<\/I><\/p>\n


\nThe twin FIAMM Italian horns are not only much louder
\nthan the weak stock offering, they are also paired out of
\ntune, the resulting interference effect on the two sound waves
\nmaking the output truly obnoxious. You want that in
\na world which often does not see or hear bikers,
\nespecially those on quiet BMW airheads. As the horns
\ndraw high current I added a relay to avoid frying
\nthe relatively lightweight horn button circuitry.<\/I><\/p>\n


\nThe horizontally opposed boxer engine design lasted through
\n1995, but remains available in some of BMW’s latest
\nmachines where it is now oil and air cooled. Here the
\n1975 valve cover compares with that on a 1994 R100RT
\ntouring machine. No prizes for guessing which I prefer.<\/I><\/p>\n


\nIn Scottsdale, Arizona.<\/I><\/p>\n


\nA happy owner, with the bike on an all American
\nHandy bike lift<\/a>. The hair is greyer but the smile is
\nevery bit as wide. <\/I><\/p>\n

<\/center><\/p>\n

I wish I could tell you that I am looking forward to the next 35 years with this beautiful machine but statistics and anno domini<\/I> suggest otherwise.<\/p>\n","protected":false},"excerpt":{"rendered":"

Thirty five years of happy wrenching and riding. I became the custodian of my 1975 BMW R90\/6 ‘airhead’ motorcycle 35 years ago today, buying it for $2,000 in Los Angeles from the original owner with just 15,000 miles on the odometer. Ren\u00e9, the wonderful Chilean seller, was returning to the country of his birth and … Continue reading BMW R90\/6 – 35 and 50 years on<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[96],"tags":[],"class_list":["post-41092","post","type-post","status-publish","format-standard","hentry","category-motorcycles"],"_links":{"self":[{"href":"https:\/\/pindelski.org\/Photography\/wp-json\/wp\/v2\/posts\/41092","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pindelski.org\/Photography\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pindelski.org\/Photography\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pindelski.org\/Photography\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/pindelski.org\/Photography\/wp-json\/wp\/v2\/comments?post=41092"}],"version-history":[{"count":5,"href":"https:\/\/pindelski.org\/Photography\/wp-json\/wp\/v2\/posts\/41092\/revisions"}],"predecessor-version":[{"id":41112,"href":"https:\/\/pindelski.org\/Photography\/wp-json\/wp\/v2\/posts\/41092\/revisions\/41112"}],"wp:attachment":[{"href":"https:\/\/pindelski.org\/Photography\/wp-json\/wp\/v2\/media?parent=41092"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pindelski.org\/Photography\/wp-json\/wp\/v2\/categories?post=41092"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pindelski.org\/Photography\/wp-json\/wp\/v2\/tags?post=41092"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}