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1969 "R" Technical Discussion
 
 
 

 

We are located in sunny WHITE ROCK, BC, CANADA

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THIS SITE LAST UPDATED Novmber 14, 2009

 

 

 



My 1969 NORTON "S" Commando Story

This restoration was 10 years in the making. A stock 1969 Commando engine was found through the Buy-n-Sell, partially installed in a chopper frame, but thankfully was never completed. From that start with only a complete engine unit, sourcing for all the remaining correct and original parts got underway. 10 years of collecting all the "right" bits culminated with a three month restoration.

The only out work done was cadmium plating, chrome plating and powder coating. All other work was completed in house (painting, polishing, wheels rebuild, engine rebuild, cylinder head rebuild with new valves, guides, springs, wiring & electrics).

The tank colour is as per the original heavy metal flake blue, using House of Kolor flakes covered over with a quart and half of urethane clear on an original blue Fiberglas tank.

Only modifications from stock include 850 box section head steady, adjustable isolastics and modest use of stainless fasteners where chrome was originally (like the fork cap nuts, head light bolts, triple tree nut and washer, air cleaner screen) and also stainless spokes. Maintained use of original fasteners generally throughout.

My Engine is low miles, standard bore, with points ignition and the original Amal carbs. The engine came with a NEW factory warranty replacement gearbox.s6

This bike was last on the road in 1971. It had fallen victim to an unfortunate incident with a car and a fence. My research indicates that the original owner bought the bike in Vancouver in 1970, and ran it for approximately 3 months before the transmission gave trouble and was replaced under factory warranty. Several weeks after the rebuild, a lady driver lost control of her car and crashed through the back yard fence of the Norton owner's house, colliding with the motorcycle. Damage was sufficient that the bike was written off and the owner suitably reimbursed.

The remains of the bike were passed along to his friend and it became the object of a transformation to a chopper. When I located the bike in 1993, not much was left intact except for a complete engine (gearbox, primary and carbs), rigidly mounted in a water-pipe fabricated frame, with girder forks and a large 16" fat rear tire (somebody's 1970's psychedelic dream).

The engine, despite years of dirt accumulation, looked like it had never been apart. When I inspected the gearbox, it was in a new housing, new shafts and gears with NO sign of ever having been driven. The engine internals were mint and have only received superblends, new big end shells, rings and a head rebuild.

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1969 "S" TECHNICAL DISCUSSION

Here is a brief synopsis of the "S" Model (gathered from various sources)

 "S" Production Engine #'s start 131257  (Mar 69) to 135088 (June 70) mine is 131976 about June 1969 - Remember 1969 is THE year of all years - man on the moon and the '69 Bonnie.

 The "S" was the first Commando with points on the end of the camshaft (more reliable and easy to adjust) also with an integral rev counter drive - This engineering change was noted on production engines with a new model number 20M3S designation. The 20M3 Fastback and R model retained points behind cylinders until September '69, eng #133668. The R ended production by September 1969 and it is unlikely it ever received the 20M3S designation (so if you see an R with points on cam, it may not be pucker - I will stand to be corrected on that for sure).

The R was the initial step at "consumerizing" the Commando - it retained shrouded front forks, fastback oil tank/side covers and low level sausage exhaust (similar to the Atlas), but had the new  fibreglass roadster 2.7gal US sporty gas tank and pancake seat like the S. The R model ditched the Fastback duck-tail fairing and large oblong tank. For further discussion and technical information on the "R" follow this link

The S took it all the way with naked front forks and high level exhaust pipes and peashooters. The first roadster with low level peashooters came in March 1970, while the S was still in production up until June 1970.

s book

Note, all early 68-69 Commando engines were stamped model ref 20M3 for Fastback and R model with the points behind cylinder. For the models with points on the camshaft, these ALL became 20M3S, which also meant that from eng #133668 all Fastbacks, Roadsters were also numbered 20M3S. This has been a point of confusion for a lot of people when a restorer finds an engine or bike with 20M3S and assumes it is an S, but in reality most likely a roadster or fastback. The 20M3S model ref was carried right through 1971 until the 200000 series 750's of 1972 or later.

Items specific to S (and the early 1970 Roadster)

  • Halo headlight mounting which includes special top triple tree (S & Roadster)

  • naked front forks - chrome stanchions (no shrouds or gaiters as on the Fastback and R)

  • fibreglass tail light in silver metal flake (also used on R)

  • special chrome chain guard rounded with cut-outs 

  • chrome shrouds on shock absorbers (all models)

  • silver painted barrels (also R)

  • chrome trim to seat

  • high level exhaust system (on left) with heat shields and special rear mounting bracket (only used on S)

  • peashooter silencers with conical ends (high level on S). These were later used upswept at low level on the first Roadster fom eng#135140. The Fastback still used Atlas style sausage mufflers until 1970 when from engine #139571 the Fastback MKII used the upswept low level peashooters.

  • centre mounted oil tank with integral air cleaner backing (used on first Roadsters also). The Fastback & R used different units, an oil tank with integral large side cover

  • chrome fenders - rear fender with crease for tire pump mounting

  • removable fibreglass side covers - right side with toolkit storage, left side with key ignition switch.

The early 69-70 S, R, Fastback and Roadster shared some common items

  • frame with lightweight centrestand mounted to frame cross tube, side stand bolted to frame tube plate

  • 3 stud bolt up rear wheel - no cush drive (great for quick starts, hard on chains and sprockets)

  • twin leading shoe front brake

S Colours

  • 1969 S colours were fire flake red, solid sapphire blue and later in fire flake blue

  • 1970 S came in a variety of metal flake colours - red, blue, emerald green, bronze, purple & silver, plus solid yellow (also common to roadsters of that time)

Hardest parts to find for an S

  • the small plastic caps for the front fork pinch bolt / halo bracket nuts, I machined replacements from Stainless.

  • silver metal flake tail light complete with red Lucas reflectors

  • serviceable centre stand or side stand

 Changes from stock on my bike

  • flexible plastic rocker feed line (not the solid metal pipe that cracks and breaks)

  • adjustable isolastics

  • 850 box section head steady

  • rear muffler bracket mounting and back loop gusset reinforcing.

  • 3.25x19 front tire in lieu of 3.00x19 original spec (not available)

Mine still retains points ignition (not Boyer) and original carbs

 After market parts used on my restoration

  • seat, a reasonable repo, shape should be more flat/fat at rear

  • exhaust headers, mufflers and heat shield

  • SS spokes

  • chain guard

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rs-s brochure

Photo Courtesy of Robert Smith, Freelance Writer, Vancouver, BC. email: robert@smith.bc.ca

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Award Winner "1st Place - Low Production Commando" at the Positive Earth Rally, International Norton Owners Association, July 17-20, Lumby, BC

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BMOC Award Winner at the 18th Annual Classic & Vintage Motorcycle Show, April 13, 2003 Tsawwassen, BC

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motoeuro

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Moto Euro Magazine Feature Article Fall 2003 Issue by Robert Smith