The following is a story that has been over 30 years in the making. Paul Kirkman was a member of Canberra Road Racing Club in the halcyon days of its early existence, the late 1970’s. And Paul built himself this very special BMW racing bike of which we were all in awe at the time. As noted, Paul re-established contact with me through a mutual friend and he has kindly supplied me with the story of his BMW along with some fabulous photos AND a video. I could tell you the story, but I’m going to let you read the story, in Paul’s own words. WARNING: This is a very long article, but well worth following through to its conclusion.
“Hi Phil, Sorry this has taken a while. I’ve really had to scratch the old grey matter, 30 years plus is a long time ago. Please excuse the quality and lack of photos. Too bad digital cameras didn’t exist back in the 80’s. I’m not 100% sure on the time line for some of the changes to the bike , it is the best I can remember. Some of the gaps in time between running the bike were due mainly to working away from home every week for long periods of time and the other usual things like buying and renovating a house.
The bike basically started off as per the description in the picture above. I had been holidaying at Reg’s place when he told me what he was planning and I said I would be interested in buying one. Rob North eventually built the first chassis and after it was displayed at the LA Bikeshow I was able to buy it. I don’t know what happened but Rob only built the one chassis for Reg, which was good for me but bad for anyone else who wanted one. The chassis was more of a TZ750 Yamaha style. i.e. the shock was connected to the steering head.
Rob had built a couple of TZ250 chassis for Kenny Roberts previous to that. The other well known Rob North chassis was the F750 bike Pridmore rode before the BMW superbikes. It had a monoshock added to it by mounting a plate to the back of the gearbox and brackets on the upper frame tubes and attaching a racing car style shock to it.
The R90S superbike had a monoshock swingarm added to a standard R90s frame by connecting the top of the motor to the single backbone tube via an A type frame. Bracing was added from a point above the swingarm pivots to that point also and also to the steering head. The shock was mounted to a bracket on the backbone tube. At the time the bike arrived I was living in a 2nd floor flat and had nowhere to work on the bike or store it safely. I was also in a job where I worked out of town most weeks so it has always been a struggle to find the time to work on the bike. I assembled the bike in my bedroom and kept it there for a few months until I moved to somewhere with a garage. The bike was as delivered except for the wiring harness, front master cylinder, front brake calipers, headlight shell and ignition coils.
I also realized that I would need an uprated motor for the bike so I sent the heads off the R90s I owned and got Reg to relocate and port the inlet tracks, fit 45mm inlet valves and 40 mm exhaust valves, and double valve springs. He also supplied a high performance Crane camshaft, lightened flywheel, 10.5 to 1 Venolia pistons, 2 into 1 exhaust pipes and a large capacity sump for it. I sourced the rest of the engine parts in Australia and once every thing arrived Dave Gordon at Doug Bryant Motorcycles in Canberra was good enough to assemble it for me.
Once I had all of the bits I managed to assemble what I thought was a road bike that could be registered. I decided to run the motor in at Oran Park so I took it up and had some fun on the short circuit. The bike was totally different to riding my R90S around there. I took it to rego and after 3 visits we finally came to an agreement on what constituted a legal road bike.
I rode the bike on a few day trips to the Castrol Six Hour race and an Oran Park meeting. It attracted a lot of attention. I also managed to buy a close ratio gearbox for it around this time from Don Wilson. Reg also managed to get a pair of EPM mags to replace the Morris mags. The EPMs were a 2.50 x 19 front and a 3.00 x 18 rear that allowed wider tyres than the 2.15 front and rear Morris wheels. I had a little bit of track time at the “speed and reliability” day CRRC held at Macarthur Park. (I borrowed a Super 8 movie camera and have a few minutes of footage from that day. The audio is bad but when I get some time I will edit the good bits and put it up on Youtube) I had a couple of club race days at Oran Park and one of the race days at Macarthur Park but I wasn’t a good enough rider to do the bike justice. The bike was still a registered road bike and it was a case of removing the glass, mirrors, number plate, and fitting racing number plates and a race exhaust system and away I would go.
In 1982 I decide to retire the bike from road use and have a go at the Gowanloch Formula European and the Peter Stevens Thunderbike series. Somebody put me in touch with Mike Howard from CRRC and that was really lucky. Mike had the one thing you need to make a BMW go fast, he was an very smooth racer.( Ken Blake, Joe Eastmure, Tony Hatton, Reg Pridmore, all smooth racers) I put a set of 40 mm Dellortos on to replace the 38 mm and away we went. Mike was able to get 100% out of the bike. It wasn’t that fast in a straight line, it would just hold out an F or G stock model TZ 350 down the long straight at Oran Park and that was only because of the initial jump Mike could get out of the corner. Mike found that it stopped really well, was solid in the corners and powered down hard out of corners, and used that to good effect. He also found the the BMW R65 front forks weren’t up to the task so I fitted a set of 38mm Marzocchi forks and triple clamps. Ian Gowanloch made up the bearing adapters to fit the steering stem into a BMW steering head and I made the brake caliper adapter plates to suit the smaller BMW discs. The other thing we did was to remove the starter motor, alternator, BMW wiring harness and switchgear in an effort to shed some weight. (see picture of Mike Howard at the head of this story -Ed). In September that year I had another holiday at Pridmore’s and Reg built me a set of race pipes that we cut up to fit in my suit case for the trip home. He also helped me get a set of Carillo conrods made up and a friend of his at a machine shop lightened a clutch pressure ring. I also bought a roller camshaft that gave a little more lift and duration. From memory we finished 5th or 6th in the Gowanloch series and 2nd in the Peter Stevens series. We were in with a shot at the final round of the Peter Stevens series at Sandown but the total loss ignition system developed a gremlin and that cost us big time. The other bad news was that Mike decided to retire. I decided to give up on any serious racing effort as well (a kid named Magee and Bob Brown’s Pantah had a bit to do with the decision) I was lucky that a few friends had thrown some money in during 1982 when it was really needed.
In mid 84 Jeff Gooch had a couple of races at Oran Park and Winton. He pointed out that the 19 inch front wheel was a drawback and Gowanloch’s loaned us an 18 inch wire wheel with big disks. I adapted that to fit and Jeff approved of it (slick on the front help heaps) so I invested in an 18 inch Campagnolo mag, big disks and lightweight front calipers. Also got the top half a TZ350 Yamaha fairing on it. I tracked down a Krober ignition and tacho for it and that stopped any repeats of problems with the total loss system.
The bike sat around then until late 86. I did acquire a set of 12.5 to 1 Venolia pistons and had those bored very tightly. A check of the compression ratio didn’t come out as expected so the squish band clearance was reduced to the minimum and that solved the problem. I had met a guy at a race meeting at Calder many years before by the name of Ed Colliver who owned a fiberglass business in Adelaide called Canuck Products. I was crewing on a small sailing skiff and the national titles were in Adelaide after Christmas. I managed to do him a deal where he could take the bike and race it at McNamara Park while I was sailing and in return he would make a full fairing and seat. He raced the bike and when he returned he said it went like a jet but the clutch made a funny noise for a little while. When I looked at it I could see that the sheet metal diaphragm on the pressure plate had torn off. That was a good sign as I was told in America that that didn’t happen until the motor was making real power. Ed spent about a week modifying an RGB 500 Suzuki fairing to fit and a seat off something else he had a mould for. There was a lot of building up areas of fiberglass and grinding away the original glass to make it fit. After a quick coat of paint we took it to A.I.R. for a few laps.
I rebuilt the clutch into a type of slipper clutch. Unfortunately I was tied up with other things at the time and it took a long time. The bike was stored to the mid nineties and I decided to give it a run but the front wheel was very corroded on the inner side of the rim. I decide that 17inch was the way to go so I got a secondhand wheel out of a Suzuki 250 roadbike and spent a long time making up brake carriers and caliper adaptors. Around about 2003 a friend did some laps at Wakefield Park to try the front out and a little while later we decided to do a PCRA meeting at Eastern Creek but it was washed out. Then in 2010 my neighbour convinced me to service it and fire it up which we did one Sunday evening. I don’t think a lot of the neighbourhood enjoyed it. In 2013 I finally built a set of starting rollers for it and serviced it again and fired it up. The neighbours seem to be slowly getting used to it. I had decided to try and sell it so I thought it would be an idea to run it at Wakefield and see what needed fixing. With your help I was able to catch up to Mike Howard and he agreed to have a ride on it and catch up after 30 years. The weather was a disaster but the rest was a good day. Hard to see where 30 years went.”
(Ed: And here is the video of that test day at Wakefield. Edited by Paul.)
[youtube]http://www.youtube.com/watch?v=ffyl8lC-dPo[/youtube]
As an aside, Paul also sent me these photos and details.
“Outfit. This is an Outfit that Rob North built for Reg Pridmore. It was powered by a Don Vesco prepared TZ 750 Yamaha motor. Reg raced it for a while in the USA and took it to the IOM once. Unfortunately the jackshaft driving the back wheel broke during practice and couldn’t be fixed for the race.”
As I have always said, I am in awe of special builders and this one in particular because of my close involvement with Paul back in the day. The bike IS for sale and will probably unfortunately end up in the USA unless a local buyer can find the money to save it. A unique piece of engineering that should stay here and a great story as well, I hope you agree. Thanks for reading.