The source of our passion

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Suzsmokeyallan
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The source of our passion

Post by Suzsmokeyallan »

Back in the beginning there was this little idea.

https://www.youtube.com/watch?v=M1_1GHFxdBo" onclick="window.open(this.href);return false;
Two strokes, its just that simple.

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Craig380
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Re: The source of our passion

Post by Craig380 »

In the 70s there was quite a well-known British special called Red Shift, which had a monocoque frame made of plywood honeycomb (a bit like the carbon-fibre monocoque frames for the RG500 in the 80s, the headstock and swingarm mounts & arm were alloy) with a Triumph Bonneville motor. Forks and wheels were conventional.

It was covered in several magazines: an engineer built it just for fun, he reckoned the frame weighed less than a conventional steel tube type but more than twice as stiff. It looked cool, too.

If I was him, I'd have used a motor that vibrated less :wink:
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Si
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Re: The source of our passion

Post by Si »

Hi,

just been searching for info on that very bike. Anybody have mag articles etc? Apparently although being a 360deg parallel twin transmitted vibration was minimal due to the engine being mounted ala MZ, i.e big rubber bung between the cylinder head and frame and the engine allowed to pivot at the rear. Very good power to weight ratio and the frame was super stiff. Always thought of building something similar but whether I'll get around to it is another thing,

Si.
Craig380
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Re: The source of our passion

Post by Craig380 »

Red Shift was definitely featured in a mid / late 70s edition of Bike magazine, I remember searching for a scan of the article but couldn't find it anywhere. If I remember right it had a cast alloy steering head and combined engine plates / swingarm mounting connected by a steel truss rod to tie them together.

These days I think you'd be better off using the aluminium honeycomb material like on the Ciba-Geigy Suzuki RGs of the 80s ...
1976 GT380 - wounded by me, and sold on
2006 SV650S - killed by a patch of diesel and a kerb in Feb 2019
2017 SV650 AL7 - naked and unashamed
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Re: The source of our passion

Post by old racer »

Seely built a similar TR500.
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tz375
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Re: The source of our passion

Post by tz375 »

What was that Seeley made of? I seem to recall that is was fabricated from sheet aluminium welded up but I need to go and check that.
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Re: The source of our passion

Post by old racer »

Yes sheet aluminium,I think they used rivets to,
I have got pics in a magazine somewhere but god knows where,
I think they only ever made one,It was to heavy to race.
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tz375
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Re: The source of our passion

Post by tz375 »

I want to say that there was a picture in the book on British Frame Makers, and there are probably more in the book on Colin Seeley.

And let's not forget the Ossa that Santiago Herrero raced. It was also an all welded monocoque. And there was the Ariel Arrow and Leader too now that my brain is starting to wake up and communicate.

And of course the Commando frame that Peter Williams designed.
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Re: The source of our passion

Post by old racer »

The John player norton challenger,Cosworth motor,It was at the the japanese classic motorcycle show in stafford england last month.
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tz375
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Re: The source of our passion

Post by tz375 »

Apart from the Angry Ant Paul Lewis, that bike didn't achieve a lot as I recall. Technically interesting though.
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Re: The source of our passion

Post by Craig380 »

I've got a couple of articles from Classic Racer about the Quantel Cosworth, and the Heron-Suzuki RG500 with the honeycomb frame. I'll try and get them scanned, they make interesting reading.

From memory, the Quantel's big problem was the engine was a bit of a pup. Quick enough but it had chain-driven balancer shafts that were sensitive to over-revving (which is kind of an occupational hazard when racing ....) meaning they would go out of phase or break if the rider tried to ride the bike in the 2-stroke way of hard braking while banging down three gears into a corner.

The Heron Suzuki was pretty successful for a local effort but never got the support of Suzuki Japan because of the not-invented-here syndrome.
1976 GT380 - wounded by me, and sold on
2006 SV650S - killed by a patch of diesel and a kerb in Feb 2019
2017 SV650 AL7 - naked and unashamed
Craig380
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Re: The source of our passion

Post by Craig380 »

Interesting article here about the Norton / Quantel Cosworth: http://www.odd-bike.com/2013/02/norton- ... -last.html

And this excellent 1973 documentary about Norton at the Isle of Man TT: https://www.youtube.com/watch?v=a-SOXVV ... e=youtu.be
1976 GT380 - wounded by me, and sold on
2006 SV650S - killed by a patch of diesel and a kerb in Feb 2019
2017 SV650 AL7 - naked and unashamed
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