The Story of the Fastest Norton

Here's the story and it's not a bad read and even if there's only a grain of truth it is still a bloody quick old cycle.

Cash

But...but...but... THAT'S IMPOSSIBLE!!!!

Ended with a bang though - - layshaft bearing went and took out the GB case - ouch.

nice article, but......oh shit, here we go again.....

I'm curious....what is the obsession with high speed and Commandos? I like the Commando because it gives the 'sensation' of speed at 70 mph that I was not getting on a late model Ducati without getting into licence loosing speeds.

good question 72combat? I feel the same way as you do, I don't care to go more than about 80 anyway.

I have modern bikes if I want to cruise at 100 out in the desert where I live.


But the fastest Commando story is interesting: The motor is obviously far from stock and a 24 tooth sprocket is used
for the 130 mph.



I am having a lot of trouble reading the article, having to use a magnifying class and much patience!

batrider said:

Ended with a bang though - - layshaft bearing went and took out the GB case - ouch.

Click to expand...

That's not as big a bang as several crankshaft/crankcase stories I've heard right here on this forum, and the engines weren't as highly modified...

I took out the gear box on my new combat and did right well. 6 gears, both shift forks, both shaft's 2 bearing's and of course the main case. was not a good day :evil:

batrider said:

Ended with a bang though - - layshaft bearing went and took out the GB case - ouch.

Click to expand...

Why? If ya got to ask - never mind. There are those thank goodness that ask
Why Not!

Right off the bat they start making errors.

The article states "Key to the modifications was the use of the Double-S camshaft with a profile similar to that used on the 650ss twin of the Sixties." and "head face was skimmed to raise the compression ratio from 9.0 to 9.75"

The 850 used the same cam as the 650ss, except for the mods necessary for the different tach and point drive. Also the stock compression ratio of a 750 Commando was supposed to be 9:1, but the 850 is listed as having lower compression in the 8.X:1 range.

So before the internet was putting garbage out there for everyone to eat up, it was up to hack magazine writers.....

Also Cycle World had one of the first 750 Commando production racers in 1970 and tested it in an article and it ran over 130mph at on the straight at a road-race track in California with 30mm carbs, so I would hope an 850 would be able to achieve something similar.

It is important to note that the bike being tested here is a Gus Kuhn built 850 hot-rod, not the Norton Villiers FACTORY built 850 that Dave Rawlins was using. Although their pics and names are sprinkled through the story.

This is also not the MCM magazine article that spelled out the mods done to the 850, as shown on the factory published Tuning Sheets 1 & 2.

I like Debby's statement she used on a recent thread:

"I'd rather ride a slow bike fast, than ride a fast bike slow".

When I'm splitting traffic on I-275 or US19 down here in Florida between 80 and 90 MPH I'm GLAD there isn't much more to be had from my old girl....Probably why I'm still around riding after 33 years astride my Combat.

beng said:

Also Cycle World had one of the first 750 Commando production racers in 1970 and tested it in an article and it ran over 130mph at on the straight at a road-race track in California with 30mm carbs, so I would hope an 850 would be able to achieve something similar.

Click to expand...

This one? Is that a pre-production Production Racer? Drum front brake and the seat doesn't look finished. I bet that was tweaked a little and I bet Brian Slark had something to do about it. :mrgreen:

Thank You . 8)

The ' CLYMER ' manual ( Young Floyd's in fact ) HAS the ' Norton Tuneing Bulliten,' or at least the diagrams. Last Pages .
The ' NORTON Commando ' manual . OBVIOUSLY .as far as ' errors ' go , thats standard for most of us , occasionally . :wink:

Back in the day , ( thats a later thingo , the first one ) they poined out that he used a 18 in rear , and went to Race Rubber
rear , to ' trim ' the time , the 4.25 TT100 spinning to much .

The Bearing , blankety production costs . Lower price ones obviously inferior to the expensive ones .
Accountants / profitability figures again .Ordinarilly supplies arnt ordered by ' We'll get The MOST Expensive ' principal .

Except By Brough , Bently , R/R , Merc . . . . . a quanundrum .