1973 Superbike Shootout!

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I rode a Z900 Kawasaki when they were new. To me, it felt like a British 350 but faster. My 500cc Triton always felt huge but slower. If I dropped the gearing it was faster than a Z900 around the slow parts of Winton. But down the straights, a Z900 would make really go backwards. I beat plenty of RD350s and a Honda Black Bomber was hopeless. The CB750s which were fitted with 450 pistons to become 830cc were fast enough, but did not handle. These days the CB750s are 1100cc on methanol and full of titanium - still useless. Although the guys who race them think they are great. If I race again, they will get upset because I have them sussed.. Last time I had a problem when I was in front - DNF. But it won't happen again.
 
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The race for last place can be more fun than winning, if the other guy has ego and you know it. My ambition is to get my Seeley 850 into a race where there is a good guy on an SD900 Ducati. There are only 3 left racing around here and all are in a later period where they race against two-strokes and four cylinder superbikes. It is all very futile.
 
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I don't like feeling depressed. Riding a race bike on public roads would do that to me. It is like using a racehorse for trail riding. If I was going to buy a road bike, I would buy a late model boxer BMW. It is nice and quiet doesn't vibrate and is light enough to be sane.
When you ride a race bike on a race circuit, the risks are minimised to a tolerable level and there are no speed limits. So you can use the bike in the way God intended. It is the ultimate in fun, especially if there is another idiot there that you can have a go at. I actually envy those guys who flew Spitfires and Messerschmidts during WW2. They might have been shit scared, but I watched a video a few days ago in which one of them said 'I had an absolute ball'. He used to fly a P51 Mustang and fight the Luftwaffe.
I am 79 and still want to race again, even though I am susceptible to stroke. It is a ferocious addiction.
Peter Egan said the racing addiction made Heroin seem like a vague craving for something sweet.
I rode a Bridgestone 350. I liked it, but I did not buy it. Two-strokes are faster but have no soul. My methanol-fuelled T250 Suzuki was an absolute blur, but did not inspire me. The guy I sold it to won 28 races and four historic championships with it - so what ? - I like a bike which makes me feel the hair growing on my chest. Not one which dies in the first mild breeze. Once you have a Commando engine spinning high, nothing stops it.
A while back I sold a good TZ350G to buy the 6 speed TTI box for my Seeley.
I've had 3 RD400s. One was my first new bike. Sold it to buy my first Commando. I've got one still in my mom's garage. Its fixed up kind of like a replica of the first one I had. DG pipes and heads, rearsets, air caps on the forks, bronze swing arm bushings, and car coils fixed to the front downtubes. I had Scott Clough rebuild and port the engine, and work on the squish in the heads. He did a lot more transfer port work than timing. Its quite strong without being pipey. It has a Yamaha rack and stock seat. I toured a lot on the first one. need to walk over and change the gas, oil, and plugs. put the new battery in, list it, and sell it. Oh yeah. Banshee reeds, too. Scott Clough is as good as anybody on two strokes. There are way better pipes, but there is the whole replica thing.
 

dero

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We are getting off topic here a bit , but while we are on the subject .
Two young greasy haired teenagers that lived up the road when I was a kid owned Bridgestone bikes , only small , but they made an impression on me that never faded.
I dont think I have ever seen one since .
 
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We are getting off topic here a bit , but while we are on the subject .
Two young greasy haired teenagers that lived up the road when I was a kid owned Bridgestone bikes , only small , but they made an impression on me that never faded.
I dont think I have ever seen one since .
It's a conversation not a lecture.
 
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It's a conversation not a lecture.
It is about time somebody made that comment. Censorship kills conversation. If you cannot discuss, you should not have a brain and probably don't. I am willing to read anything which appears on this forum. If I disagree with it, I usually say why. If we talk, we can help each other.
 
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This shootout was the followup to the famous 1970 article in which the Commando S ran an astonishing quarter mile in 12.69. I had always wondered what had been done to that 750 to get it to run so fast. Luckily Brian Slart is on Facebook and responded with the answer.

He also filled in some details that the 850 in the above 1973 Shootout was pretty stock. Cycle said it had a SS cam in it. Brian said it was the stock 850 cam.
I knew the 1969 bike had a fixed advance, and that the rocker springs were replaced with shims according to the article, as I recall. What else was it?

Dunstall 810 road test data. 8 short years later, a GS1000 was the second production bike I saw in the 11s.


Test data from the 1972 Cycle Guide road test



I always get off track
 
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The Bridgestone could walk away from a CL250 Honda. It had a strange rotary gearbox along with rotary valves. It could be a normal shifting 5 speed or a 4 speed that shifted from 4th to 1st by moving a lever on the engine case, not very useful.
I remember the 5 down (or up, not quite sure), neutral, then 5 down again. Odd but nothing wrong with it.
 
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I knew the 1969 bike had a fixed advance, and that the rocker springs were replaced with shims according to the article, as I recall. What else was it?

Dunstall 810 road test data. 8 short years later, a GS1000 was the second production bike I saw in the 11s.


Test data from the 1972 Cycle Guide road test



I always get off track
I'm not sure I buy that 11.9 sec on the Dunstall.
 
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Nothing wrong with it but shifting from top to first without coming down through the gears might be bit sudden for the tyres ? I did not ride the Bridgestone 350 far enough to discover that nice aspect. I only gave it a squirt around the back streets. There was a guy in Melbourne who had one as a road racer. It was on methanol and extremely fast. I only ever saw it race once. It ended up as part of a deceased estate. One of my friends had a Kawasaki Big Horn 350 road racer which as also rotary disc valve and on methanol. It was competitive in A grade races against TZ350s. The rotary valves give asymmetric timing which is better than piston-port or reed valve.
 
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L.A.B.

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It is about time somebody made that comment. Censorship kills conversation.
Unfortunately, your idea of a "conversation" has often been to derail a thread by going way off-topic, running on about some aspect of racing or your exploits in some past race or other which has often been nothing to do with the subject under disussion and probably why you may think you've been "censored" as you have been warned for repeatedly going off topic. Your assertions that "public roads are too dangerous to ride on" and "drum brakes are for idiots" is just tiresome.



If you cannot discuss, you should not have a brain and probably don't.
???
 
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I'm not sure I buy that 11.9 sec on the Dunstall.
Yep


Take a look at posts 1, 41 and 42
 

Richard Tool

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A great read - thanks for posting , particularly your efforts in showing the complete article. Like many here I suppose , I wanted the Commando to come out on top but that is of course pie in the sky .
Of all the competitors , how many had their engines based on a 1940’s 500 cc twin ?
 
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Ha ! Good point Richard... Yes very much appreciate You posting the article, Dave. Wow, seeing it
reminds I have SEVERAL plastic totes filled with Chopper, Easy Rider, Cycle, Cycle World,
Motorcyclist and other bike magazines from the late 60's through mid-late 80's...what to do with
them...probably have this particular issue... Oh,and probably as many filled with 8 tracks ! All classic rock and roll. Somehow I don't have the heart to pitch them... what to do with THEM ? ! Just an old guy problem I suppose...
Hope You all Have a good weekend and get some riding in. Supposed to be Mid 70's here for the
foreseeable future.
 
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Hope You all Have a good weekend and get some riding in. Supposed to be Mid 70's here for the
foreseeable future.
Unfortunately we are still suffering from wildfires and the horrible smoke. We’re getting thunderstorms in the area and hopefully some good rain. But now they are worried about flash floods in the steep burned out areas.

All to say I probably won’t ride this weekend.

It would be great to get all those magazines digitized so we’ll have them forever, even after the paper has disintegrated.
 
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I have the 1970 "Magnificent Seven Superbikes digitized, and a bunch of the performance test sheets.

Here are a couple:

74 H2 Not that quick on this day:

1974 Commando Interstate not that slow this day

Cycle Guide 350 Comparison stats Kawasaki failed to finish. The 315cc Suzuki and Bridgstone were quick, but didn't handle well.
 
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I had forgotten about the shift pattern on the Bridgestone. A local kid had one, he was a mad scientist sort and liked it because
the engine was different. I lusted after a Trident. Rode one for 15 years. Poor judgement.
 
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Re; Super Seven's comment "Kawasaki 750 not that quick in its day"
Maybe it was not to some people's eyes, but this is straight out of the crate, without any tuning mods which would improve the ss1/4 times.
What was eye watering and a pocket/ wallet killer was the fuel consumption.... could it get any worse?
 
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Petrol was cheap. So was oil. My Trident was no mpg meister either.
 

concours

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Re; Super Seven's comment "Kawasaki 750 not that quick in its day"
Maybe it was not to some people's eyes, but this is straight out of the crate, without any tuning mods which would improve the ss1/4 times.
What was eye watering and a pocket/ wallet killer was the fuel consumption.... could it get any worse?
The two strokes of the day were equipped with chrome plated sink drain pipes. The magic occurred when a proper set of tuned expansion chambers were fitted, some Uni filters & jetted to suit.
The realistic 5-10 h.p. gains would be a game changer against the 4-stroke plodders.
 
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