R65LS Decal Mounting

The Airhead 247 podcast has extended itself into a video logs and also has a website. On the website they have a (incomplete) collection of technical advisories including the one for decal placement on the R65LS.

I hadn’t realised that the stickers were applied by the dealers. I’ve seen bikes with odd placement, including the rear sticker above the roundel rather than below, and also seen Henna Red bikes with the blue stickers appropriate for the Polaris Silver bikes. I’d thought that these were the result of mistaken alterations by various owners, but it seems that they might be mistaken application by the dealers.

The 247 website is at https://airhead247.com/. R65LS sticker placement is at https://airhead247.com/service-bulletin-r65ls-decal-mounting-00-026-82-2053-3-82/

The podcast concentrates on airheads but occasionally wanders into other areas like the BMW K series.

The R65LS engine, in common with R45 and R65, are type 248, not 247.  The two engine series have different strokes, 248 has 61.5mm compared to 70.6mm on the 247. (Other changes in capacity are effected by changing the bore.) I’m not aware of this being acknowledged on the podcast, they have used “247” as synonymous with “airhead”.

BMW Desmodromic Superbike

 

In the January 24 2007 edition of Australian Motorcycle News I found a curious article about a desmodromic BMW. It was under development but never raced in the superbike class for which it was intended.

The design references the “legendary Rennsport 500cc Boxer GP Engine” described in Classic Motorcycle Engines. It has a number of important differences:

• Cylinders are rotated so that the air intake is a downdraft from the top and exhaust is directly out the bottom.
• Camshafts are driven by chain rather than bevel shaft, with a secondary chain driving the inlet cam from the exhaust cam.
• The exhaust cam on the bottom of the head has been staggered slightly to give better cornering clearance. This makes the head look a bit like it has been tilted or bent in at the bottom.
• Bike is 1000cc. 

The bike was developed in the early 1990s and, apart from an outing at the Goodwood Festival of Speed in 1999, has been hidden or a museum piece.

I've uploaded a scan to https://drive.google.com/file/d/1Z_2zaSxT7sOq7AZTG9WCpb1LXAz4HwYF/view?usp=drive_link

Original was Australian Motor Cycle News, Vol 56, No 14, 24 Jan - 6 Feb 2007. Author Alan Cathcart, Photography Arnold Debus. 

Drivemag have a similar article, also by Alan Cathcart: https://riders.drivemag.com/features/bmw-boxer-r1-desmo-test-stillborn-superbike/

Desmodromology have a page on it and mention that 4 were built but only one is rideable: https://www.desmodromology.nl/bmw-r1/

Haynes Manual

My primary reference for working on the bike is the 1986 Haynes manual. All six of the airhead BMWs that I've owned have been coverd by this manual. 

It is very practical, detailing what things happen to the bikes in service, how to troubleshoot faults, and suggesting workarounds for BMW special tools. Because it deals with such a long model range of bikes it has a detailed technical history, for example in describing the forks it describes at what model years forks were changed and which bikes received the new version. 

Current version extends the range, 1970 - 1996, and calls it "2-valve Twins" to distinguish it from oilheads. 

I have the BMW workshop manual as well. This is useful and I occasionally reference it, but in a practical sense I only use the Haynes version. The BMW manual is very proceduralised, focussed on disassembly, check/replace, and reassembly. It relies on a lot of special tools many of which could only be affordable to a dealer. 

Fork Gaiters

 The bike was originally released without fork gaiters, all the 1982 publicity shots have shiny stanchions. 

My first LS had fine 14 rib gaiters, quite slim and quite sharp on the concertinas. 

The realoem parts catalogue doesn't include gaiters. Some retailers have a bulky 11 rib version that looks like it comes from a R75/5 or similar. Motobins list this as "Code: 93900    BMW: 31 42 1 234 908".  This is more bulky than the 14 rib version, not as slim and the folds of the concertina are more rounded. 

With one of my fork rebuilds I found the 14 rib version in the parts catalogue for the R65 and R80G/S:

https://www.realoem.com/bmw/enUS/showparts?id=0348-USA-06_1980_2471_BMW_R_80_G_S&diagId=31_0318#31421241666

• 02 Ring 2 31421241669 $6.97
• 03 Rubber boot 2 31421241666 $16.90
• R 65 GS, R 80 G/S, R 80 ST (80-92) R 80 G/S Fork slider

The bulky version clamps directly onto the stanchion and slider. The 14 rib version clamps directly onto the slider but needs a neoprene ring at the top to make up the difference between the stanchion and gaiter. 

I prefer fork gaiters, I like the idea of protecting the stanchion from dust and stones. I think the 14 rib version looks much better on the bike than the thicker one, but maybe I'm just biased because of my history? :-)

11 Rib version on the left, 14 on the right. 

Wedgetail Ignition

 About two years ago I became concerned about the bean can on my 200k bike and rebuilt it. This was successful, but I was never really confident that I'd done it as good as new, so I purchased a Wedgetail ignition system. This includes both the sender unit (slightly flatter than the bean can) and ignition control unit to sit under the tank and control the coil. I use a 1.5 ohm Dynacoil, not the OEM version. 

The parts arrived well wrapped but the ICU was damaged, presumably drop kicked during transit. It was replaced without delay or argument. 

It's worked faultlessly since installation. 

ICU Under Tank

The systems are built in Australia, available in the USA, and have a Facebook page. 

Third Bike

 I wasn't looking for a third bike but a 1985 K75C was on sale locally in rural New South Wales so I went and had a look. It had only 48,000km on the clock, was in good original condition and at a good price, so I purchased it. I'm currently working through a series of maintenance jobs like replacing the coolant and brake lines: the bike is unfamiliar after nearly 40 years maintaining airheads but some things are the same. 

There's an interesting piece on the K75 by FortNine, he describes the engine as being easily capable of doing a million miles. Also, there were a couple of episodes of the Airhead 247 podcast devoted to the K75, it's available on Soundcloud, also apple and spotify. 

Starter Motor

 On a ride recently my bike started unreliably: there was a "click" from under the tank but no life from the starter motor. In each case I was able to get the bike started after a few attempts and moving it around a bit. I wasn't sure if the problem was the relay or motor itself, but neither has been serviced, ever, so I figured I'd replace both.

I purchased an Arrowhead starter for AUD219. This was less than twice the cost of overhaul parts for the original BOSCH starter. 

Shiny new Arrowhead starter installed.

Replacement was straightforward except for a couple of points. 

• There are two hex head bolts holding the starter in place. The one on the left side of the bike could be turned using a ring spanner, but the housing wouldn't allow this on the right. I had a socket that fitted, but to get access for this I needed to remove the airbox and battery, which was a nuisance. When reassembling it I used an allen key bolt, so this should be avoided next time. 
• There is a bracket on the leading edge of the starter under the timing chain cover. It has 3 bolts, two on the starter and one on the engine. One of the bolts on the starter is impossible to get off while the starter is in place, but the lower bolt, screwing the bracket to the engine, can be accessed using a 10mm socket from the front. 
• The relay I purchased had 4 connections and is appropriate for other functions on airheads, but not necessary on my bike. The correct relay has 5 connections. 
• Care needs to be taken removing the relay with a screwdriver because one of the connections is always live, and so can spark. 
• The crankcase breather hose was perished, clearly visible in the pic, and was replaced. 

LHS Spanner Access

After this was done with the original starter relay in place the bike didn't start, so I swapped in the relay from the other bike and it started sweetly, no problems. So, the problem from the beginning was the relay, not the starter itself. 

Shiny new Arrowhead starter installed.

Works BMW Flat Twin

The book Classic Motorcycle Engines has a chapter on the 1955 works BMW flat twin. I've uploaded it to:

https://drive.google.com/open?id=1gLaaD_xzHFQNXzSrnkPifBdrWnM_IWkg

The book was published 1986 and had detailed technical descriptions with historical context on 20 outstanding engines. In the case of the BMW chapter the engine under discussion dates from 1954, so the drawing and original discussion 1955, and the historical discussion dates 1980s. 

The technical description of the engines is incredibly dense, packing an almost unbelievable amount of information into each paragraph. I dipped into it tonight and I'm sure there was information that wasn't there yesterday. However, if you don't read it attentively you might miss things like the reference to the 500cc flat twin with desmodromic valve gear, unfortunately abandoned because of lack of funds. 

Full citation is "Classic Motor Cycle Engines: a new perspective on 20 outstanding designs", Vic Willoughby, 1986, Motor Racing Publications Ltd, Great Britain. 

Enjoy!

Nearly-There Sportster

In the dusty archives is this road test of the LS from 1983. The scan is from the yellowed pages of "Two Wheels Road Tests: Full tests of the year's top bikes" and includes other bikes like the Kawasaki Z750GT and Honda CBX550.

The LS was new at the time and wasn’t necessarily seen as an improvement on the recent BMW models or the R75/5 from 10 years previously. It wasn’t seen as a cost effective way to purchase a motorcycle: it carried the premium associated with BMW but didn’t have the robustness of its pedigree nor the performance of its peers.

It’s been a while since I’ve seen a Z750GT or CBX550 on the road, though…

Access it here (file is 20MB).