1973 Superbike Showdown

[Voltaire]

AC/DC? IMO, they ought to've emulated The Doors, & called it a day when their decent singer drank himself to death..

Those Castrol 6 hour regs/officials were hilarious, as was the cheating..
No R90S allowed, the bikini fairing was deemed an unfair advantage or something..

The "fork mods" - spring stiffening spacers, added to try & help keep the rocker covers from wearing right through, & dumping oil out, were needed - due to those cylinders scraping on the road..

S'pose you have gearing limitation issues with the shaft-drive too, but sure, good for top end advantage, on track..

Although BMWs of this kind are very common in the local classic club scene, even when spiritedly ridden,
are fairly easily outpaced - by my crappy ride-to-work hack mid`80s era, RZ 350 Yamaha, guess that such was the pace of progress for bike performance, in those decades..

I've got three final drives although I only bother with one due to as you say outclassed...tis fun to pass a Jap multi or Ducati when the noobs arrive, usually lasts for about 2 laps.

On a good day can hold off the highly modified Honda CB 350's

Saying that, no new parts in the motor other than bearings and rings.

More fun than bowls or darts.

[J.A.W.]

I've got three final drives although I only bother with one due to as you say outclassed...tis fun to pass a Jap multi or Ducati when the noobs arrive, usually lasts for about 2 laps.

On a good day can hold off the highly modified Honda CB 350's

Saying that, no new parts in the motor other than bearings and rings.

More fun than bowls or darts.

Good stuff.. & not even a hot cam/big valve 'n'spring kit, shaved heads,light flywheel, or programmable electronic ignition - in it?

A bloke on this side of the ditch, Greg Johnson - a crusty but fastidious/perfectionistic to the point of irritability - old school racer/engine builder was doing an excellent job on accurately rebuilding a couple of H2 cranks for me, among other things, so I visited his shop a few times, he had a few tales to tell about being party to the 6 hour shenanigans..

But he also classic raced a punchy 'Echo' BMW, it was fairly trick, & sounded real meaty, almost like a properly fettled/angry race Commando, so I do have a certain respect for what can be persuaded from the usually haughty yet anodyne Teutonic lumps..

[Voltaire]

Good stuff.. & not even a hot cam/big valve 'n'spring kit, shaved heads,light flywheel, or programmable electronic ignition - in it?

A bloke on this side of the ditch, Greg Johnson - a crusty but fastidious/perfectionistic to the point of irritability - old school racer/engine builder was doing an excellent job on accurately rebuilding a couple of H2 cranks for me, among other things, so I visited his shop a few times, he had a few tales to tell about being party to the 6 hour shenanigans..

But he also classic raced a punchy 'Echo' BMW, it was fairly trick, & sounded real meaty, almost like a properly fettled/angry race Commando, so I do have a certain respect for what can be persuaded from the usually haughty yet anodyne Teutonic lumps..

oh yeah, Ignitech ignition, asymmetrical cam, shortened cylinders, D port heads, piston machined for 1mm squish band, lightened flywheel, two into one, and engine jacked up.
Would like lightened lifters, fancy pushrods and better valve springs with titanium retainers but 1 thing at a time, currently the cam.
Finished it off today, ready to race in two weeks.

[J.A.W.]

oh yeah, Ignitech ignition, asymmetrical cam, shortened cylinders, D port heads, piston machined for 1mm squish band, lightened flywheel, two into one, and engine jacked up.
Would like lightened lifters, fancy pushrods and better valve springs with titanium retainers but 1 thing at a time, currently the cam.
Finished it off today, ready to race in two weeks.

Give 'im all heaps.. & best of Bavarian, luck..

D-port heads?

I note that current Commando performance heads, newly made by an Aussie bloke use them too,
-but flavour of the times for real hard-on Commando power is now into reproducing the highly efficient well-developed XR 750 Harley-Davidson race head architecture, & with cam/crank-tech to allow the rpm to really use it..

[gjm]

I had a Mach IV, but not a stock one. Mine made a shade over 100hp, having tweaked and fettled by James at BDK Racing south of Norwich on the UK. He now has a bona fide workshop, but when I knew him he was working out of a large garage at home.

That bike was mental. Needed a lot of looking after, but when riding it you could forgive it anything. Today's superbikes must be significantly faster, but I've still not ridden anything that gave me the thrill that bike did. Of course, I'm older and have a teensy bit of common sense these days, while back then changing into 2nd and 3rd before the front wheel came down was just how you pulled away from traffic lights.

This was in the late 80s and I'd cane GSXR-750s in a straight line, and scare a GSXR-1100 rider up to 100mph or so.

Handling really wasn't too bad once you were used to it, but not in the same league as the GSXRs. Still, the Suzukis didn't sound, or look, half as nice.

[J.A.W.]

I had a Mach IV, but not a stock one. Mine made a shade over 100hp, having tweaked and fettled by James at BDK Racing south of Norwich on the UK. He now has a bona fide workshop, but when I knew him he was working out of a large garage at home.

That bike was mental. Needed a lot of looking after, but when riding it you could forgive it anything...I've still not ridden anything that gave me the thrill that bike did.

For sure, & unlike many boring Nippon bikes, those big ol' 2T triples have character..

Here Jay Leno finally gets to ride - an original Mach IV 750, & decides he has to have one..

https://www.youtube.com/watch?v=H3Lytyt8Qmo

[J.A.W.]

& here, RB shows how we did it - back in the day.. this would likely get you arrested - if a cop saw it, these days..

https://www.youtube.com/watch?v=1N5rm0glYwY


I do recall riding an H1 500 on commuter duties in Melbourne back in the late '80s & getting hauled up for pulling a like stunt..

The cop was in an unmarked car & was busting people for not stopping at a stop sign.. I'd stopped but fanged it away..
& got the "Who do you think you are, bloody Wayne Gardner?" routine..

So I said "Well, as a matter of fact, it is a 500 2T multi, like ( then World G.P. Champ) he rides, & they all just do that, y'know.."

The cop actually had a sense of humour, & let me off with a " Yeah, well you did stop.. but, don't do it in front of cops."

[roogazza]

Still love the memory of my 72 Mach 4.
The noise, the smell of starting it up for my Sunday early morning fang.
The clanging rattling thingy was the fastest thing you could buy for the road in that year.

Many avoidance exercise was carried out and chases were short !!!!
I had a Bell painted black with bright coloured flowers on it. Gracefield one year the MOT were trying to match the helmet to the blue H2 in the Pits ! lol.

[J.A.W.]

Still love the memory of my 72 Mach 4.
The noise, the smell of starting it up for my Sunday early morning fang.
The clanging rattling thingy was the fastest thing you could buy for the road in that year.

Many avoidance exercise was carried out and chases were short !!!!
I had a Bell painted black with bright coloured flowers on it. Gracefield one year the MOT were trying to match the helmet to the blue H2 in the Pits ! lol.

Yeah, the old H2 gave a pretty good account for itself in proddy racing through the `70s..

& being responsive to the usual 2T - fairly inexpensive - tuning techniques, helped as well..

http://www.kawtriple.com/mraxl/artic...5/dencobb0.htm

[Flettner]

RZ 350? Hasn't it got a slightly larger motor now? Or am I thinking of the LC?

[Oscar]

The shed currently includes four 1973 superbikes, an H1, H2 and Z1 from brand K, and an RD350.

[pete376403]

I remember seeing Steve Dundons RD350 beating the H2s at the Marlboro race at Gracefield, one the H2s should have won because it was basically long straights. "Count" Laurie Summers was not amused, and the subsequent protest found the RD had been tweaked somewhat.

[roogazza]

I remember seeing Steve Dundons RD350 beating the H2s at the Marlboro race at Gracefield, one the H2s should have won because it was basically long straights. "Count" Laurie Summers was not amused, and the subsequent protest found the RD had been tweaked somewhat.

Ciao, got a photo from that exercise. L to R Stark,Collison and Dundoon !

[Grumph]

Ciao, got a photo from that exercise. L to R Stark,Collison and Dundoon !

Dunders is using the optional "wedge" version of the RD i see...

I miss officials in white coats, much classier than hi-vis.