CBX Racing

[Warwick Biggs]

Apologies Phil. I see Speedhut has a bigger range than I at first realised. It doesn't change the overall maths too much but there is a choice. An interesting site. Have to think about it.

[Warwick Biggs]

Here is a good link to the Kim Newcambe story:-

https://www.nzherald.co.nz/nz/news/arti ... d=10692257

[Warwick Biggs]

And the Konig. Very low c of g.

[Warwick Biggs]

When I was at uni trying to earn enuf' money to keep racing and doing all the other things I wanted to do I had numerous jobs, one of which was fixing the washing machines in other student's share houses. It was while I was doing this that I discovered that the 10 inch or so diaphragm spring in the Norton clutch in my first race bikes (seen here in the Konig lurking behind that heavily drilled clutch cover) was identical to the spring of the clutch in a Kelvinator washing machine.

More than once I managed to electrocute myself and you can imagine that when you have your head and half your torso down a top loader and you get a 240 volt bite, the shocking effect on the body constrained by the box I was leaning into created a fair bit of noise and bent panelling. I soon found better ways to make a buck but I never forgot just how rudimentary the Norton design was.

The spring being so large required a fair bit of pressure to pop the centre in and release the gears and Nortons were so prone to snapping clutch cables that I always had a spare taped to the operative cable so I could quickly change over when the nipples eventually parted company from the cables. The spring was held in place by a very large circlip and you had to be careful when working on them because when that circlip was released the spring had a tendency to explode in your face.

Sometimes I wonder how I managed to survive for so long as I blundered my way through life.

[EMS]

I remember the König motor being used in sidecar rigs. Dieter Busch, the renowned builder of sidecar rigs in the late 60s and early 70s used the design in his "Kneeler" rigs.

[Warwick Biggs]

Here is another link that refers to the engines continuing to win sidecar GP's after Newcombe's death.

https://www.odd-bike.com/2013/04/konig- ... erdog.html

It also gives more technical info and demonstrates that the Konig shared a few 'issues' with the CBX - overheating and packaging in particular, plus the odd layout. I believe they were getting around 120hp out of the outfits EMS, comparable with a TZ750. I forgot about Pasolini's death at Monza too. Barry Sheene received a lot of credit for spear heading the rider's safety group plus brick bats for refusing to ride at the TT but that string of deaths freaked everybody out. There was also Mike Duff's terrible crash in Japan that ended his/her career.

The next few years saw major changes. My home track Adelaide International Raceway was banned for m/c racing after Denny McCormack hit the concrete wall in the speed bowl (you can see it in some of my earlier posts of my TZ in this blog). I must say that I reckon that was a freak accident. It was the exit that bothered me where there was an entry from the pits and a sharp concrete wall.

Anyhow the Newcombe story deserves to be better known than it is so I raise it here even tho' the CBX connections are tenuous. The Konig was faster than the RC161 that was the design platform for the CBX.

[Warwick Biggs]

When you look at the Konig frame in the picture above you can see where Fritz Egli derived his inspiration for the Red Baron version of the CBX. Colin Seeley made this frame but it could be described as a pre-cursor to a whole range of straight backbone frames before the alloy beam became ubiquitous. Where Newcombe gained his inspiration for this layout is less clear and I wonder if anybody can identify any earlier application of the principle?

[EMS]

The large diameter top frame tube was used in early GP racing for another purpose such as doubling up as an oil tank. So done in the 1957 Moto Guzzi V8, maybe others.

[Warwick Biggs]

Was it a straight line from the steering head to the swing arm pivot? Can you find a pic EMS?

[EMS]

Sorry Warwick..had to go to the garage, take the fairing off and take a picture...
I don't think there is a design that has a straight tube going from the steering neck to the swingarm pivot..Wouldn't leave much room for an engine..

[Rick Pope]

Mike, thanks for posting that picture. The more I look at it, the more little bits I see, that were before it's time. First thing that popped out was the eccentric chain adjuster.

[EMS]

Yes, Rick, if you look into 50s and early 60s race bikes, you will find a lot of stuff the Europeans did long before the Japanese with the boom of the 70s Superbikes later received credit for.

[Warwick Biggs]

Yes, very interesting pic. Newcombe was a successful scrambles rider in NZ long b4 he took up road racing and he competed on a Greeves. They were a peculiar looking bike that used Reynolds 531 tubing and an unusual single unit cast alloy head and down tube. With the flat 4 perhaps Newcombe realised he had more room to play with and reversed that layout. In any event I'm guessing his idea for the Konig spine frame probably derived from his motocross background. I think MZ used a similar design in their dirt bikes.

Just back from the track. The CR's have to come off again. The CBX did one lap and ran OK at idle and full throttle with no visible smoke but was terrible in between. The choke mechanism has to be dis-assembled and inspected altho' it may be just a matter of fine (or rough) tuning the needles and jets. I will experiment a bit b4 putting it on a dyno but it is almost certainly just a matter of getting those CR carbs right. Its worse than a ruddy 2 stroke!

[Warwick Biggs]

I take it EMS that you are a serious collector as there cannot be a lot of those MG V8's around. I would love to see it at the track but it must be fairly heavy, especially with the original dust bin fairing.

Have you ridden it and if so, how does it go?

It would fit into our P3 historic racing class and should get a trophy just for turning up. Of course, it would be completely out-classed by the Molnar replicas that can lap quicker than some modern Superbikes.

The replicas are killing classic racing and Cathcart puts it succinctly when he describes it as a silhouette class

[Warwick Biggs]

Here is a pic from the w/e testing. I look pretty good considering how I actually felt after about 30 laps on the Suzuki. The G forces on a modern bike are a step up from the historics and I am still feeling very stiff 36 hours later.

One thing I neglected to mention was that fairly radical chassis changes on the CBX were not noticeable. Of course, I was taking it fairly easily trying to get it around with an engine that was only functioning properly at full throttle but it didn't fold on me in the corners and could not have been too bad or my attention would have been engaged.

So, the conclusion from the test 'n tune is more work is required with the carbs but the chassis changes look promising.