Sunday, 24 August 2008

Vintage Thing No.25 - Norton-JAP V-twin

Just look at this beauty! As a Vintage Thing it's practically over-qualified. This gorgeous 1000cc JAP v-twin powered, wideline Norton Featherbed won best competition bike at this year's Calstock Bike Show and when they fired it up in the tent there were huge grins all round. It sounded like a racing Morgan trike, which isn't surprising since they use the same engine - really crisp and nothing like the "potato, potato, potato" of a Harley V-twin.

These engines also went into Brough Superiors and many Shelsley specials. John Bolster used two of them chained together in Bloody Mary and went on to use no less than four of them in the ultimate Bolster hillclimber. However, the resulting 4-litre eight cylinder monster proved too difficult to start. Without electric starters, bumping it was the only way to do it and if one engine didn't catch it just right, the shocks to the chain transmission system would snap the links easily.

As for the frame, the Norton Featherbed frame is the most famous bracket for engine and two wheels of them all. It was never officially called that. The nickname came about because it was such a revelation to ride after the rigid tail post-war Nortons and it became the frame of choice for anyone who wanted to get the best performance out of their engine. Don't tune your Triumph - put the engine into a Norton frame. Since Manx Norton singles were the engine of choice in Formula 500cc car racing after the war and - for some never explained reason - Norton wouldn't let you have an engine unless you bought a complete bike, Norton rolling chassis were happily not difficult to come by.

The overall look of this bike is just right and I love the twin magnetos on the crankcase. These allow each cylinder to be individually timed. Why would you want to do that? Well, these engines are hand made Vintage Things and by individually timing each cylinder you can allow for any production tolerances. And you can retard or advance the ignition to allow for the front and rear cylinders running at different temperatures. It's not such an issue with more modern machinery. With this sort of engine, you are in much closer touch with the designers and builders.

Look at the way the front exhaust pipe goes through the engine plates. Conventional wisdom has it that the rear cylinder runs hotter than the front one due to its masking effect. But sometimes the front one runs hotter because it, too, can be masked by the front wheel. Funny old things, these Vintage Things.

Unfortunately, I didn't get to speak to the owner/constructor but Pete Low did. He said that the conrods were out of Noel Pope's record breaking machine and the gearbox had to be subtley angled to get the correct chain alignment. It's one of those machines where the more you look, the more you see.

Although I prefer disc brakes that big drum brake is entirely in keeping with the period look of the machine. This bike reminds me of a Triton on steroids. Tritons are among my favourite two wheeled specials. They just look so right to me and this bike also does it for me. It could have been ridden to the show by Ogri.

Starting it proved a little awkward but entirely worthwhile. Even if you have the weight, you need to apply it to the kickstart in exactly the right place. Pete said he'd've volunteered to have a go as the bike wore out various members of the public, "but I don't think my knees would stand it." Mindful of the stories of Bolster's JAP V-twins, we just hoped the ignition was timed correctly since a kick back from a machine this size would have put you through the roof of the tent and possibly on the other side of the River Tamar. Happily, all was well, and the bike eventually burst into joyous, riotous life.

As Pete said, "Wouldn't Hob be tempted off his Egli-Vincent by this machine?"

Of course, he would. In fact, I fear the owner may have already sold his soul to the Horsepower Whisperer to get this bike together.

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