nickjtc wrote:Thanks Paul. Yes, for the record, the Norton/Matchless hybrids all used the Norton twin cylinder engine (predominantly the 750cc Atlas) in a Matchless frame. The frame for my 1967 N15CS must have been a Matchless 'work horse' because it has the lugs incorporated for the attachment of a sidecar. Also two little tabs on the right rear frame down tube for a bicycle pump.
That frame started out as the frame for the G15/45 which was the new Matchless 750 with 3 main bearings. The frame was designed to be robust enough for desert racing.
When The G15/45 debuted in '62, it was discovered that the middle main bearing - rather than making the engine bulletproof - restricted the flexing of the crank and would up either breaking the crank or the crank case.
Norton, meanwhile, had come out with the Atlas, and they were desert raced, too. The problem with the Atlas was the head stock of the featherbed wasn't strong enough to handle the rigors of desert racing.
According to the stories, there was an Atlas with a broken frame and a G15/45 with a blown motor at ZD Motors in Glendale, California. Somebody thought to put the Atlas motor in the Matchless frame, and the Atlas Scrambler was born. The initial run of Scramblers had Teledraulic forks, but during that first year of production, the Scrambler had switched to Roadholders. I believe those bikes are referred to as G15CS 'N' Atlas Scramblers, but don't have documentation.
As many as 5000 G15, N15 and 33 (the AJS version) hybrids were built between 1963 and 1970, and there were several different models built.
-The Norton was the N15CS. The 'CS' designation goes back to AMC models of the '50s and stood for 'competition, sprung' This was the only model, as one would get the Atlas if one wanted a strictly street machine.
-Matchless had 4 G15s. The original 1962 model with the Matchless motor; the G15CS which was identical to the Norton except for tank badge; the G15CSR which had a few changes from the CS, most notably thinner spokes in the wheels. where the CS was a true scrambler, the CSR was more of a sporty road bike. CSR ostensibly stood for 'competition, sprung, road', but many called them 'coffee shop racer'; the G15MkII, which was the G15/45 with the Norton motor. This bike had the big chrome gas tank, large seat and heavy chrome fenders.
-AJS had the 33 Std, which was a G15MkII in AJS badging and the 33CS and 33CSR, again identical to the Matchless, except G15s were usually candy red with black seats and 33s AJS blue with tan seats.
The Atlas Scrambler came with nothing on it that would say 'Norton' except for the 'N' badges on the tank. This was done so the bike could be sold as a Norton, Matchless or even AJS. Some years, the bikes even came with 2 sets of badges in the crate, a winged 'M' or an 'N'.
If the bike is a '67 or '68, look carefully at the serial number stamped on the crankcase. In order to fill a large Berliner order, the factory re-stamped many AJS 33s as N15s. If one looks carefully, there's a good chance one can make out some remnant of '33' under the 'N15'. The factory had run several hundred AJS machines, but orders came in for Norton and Matchless models, and it was easier to rebrand the bikes. After all, there was no difference aside from badging and maybe color.