Norton Dominator and Featherbed Models

Norton Dominator and Featherbed changes

Sources: scanned typewritten sheet with additional handwritten notations + INOA "Tech Digest" + Steven Hudson - "Commando Service Notes" + Roy Bacon - "Illustrated Norton Buyers Guide", 1991 +Roy Bacon - 'Norton Twin Restoration, 1987 + Roy Bacon - Norton Dominator Twins 1949-1970, 1990




1952-53 Model 88 Dominator De-Luxe 497cc [68 x 72.6mm] compression ration 6.7:1 engine from Model 7; iron head; pre mono-bloc carb 276; rear brake light; featherbed frame with rear subframe bolted to the main section; short roadholder forks; angular contact ball bearing steering races; top dash panel for speedo, ammeter and light switch; underslung pilot lamp; pear-shaped mufflers; tool tray beneath the seat. Tank held down by top strap with rubber pads on frame tube rails; front tyre 3.25 x 19 inch; engine sprocket 20 T
1953   lighter front mudguard; 3.00 x 19 front tyre
1954   8inch front brake
1955   alloy cylinder head; monobloc carb 376, 1-1/16in; subframe welded to main frame; full width alloy hubs; rear number plate boxed in; round plastic badges on the tank
1956 Model 99 introduced "Model 99 engine 596cc [68 x 82mm]; monobloc carb 376, 1-1/16in; compression ration raised to 7.4:1; 21T engine sprocket so overall gearing was higher Model 88 compression raised to 7.8:1 new oil tank with ribs and matching battery box; dash panel removed; speedo, ammeter and light switch in headlight; pilot light in headlight;"
1957   AMC gearbox (introduced in 2nd half of 1956?); tubular silencers; round footrest rubbers; extra finning on cylinder head between exhaust ports; front brake drum cast without bolts; petrol tank painted with separate chrome side panels
  Model 77 introduced single down tube brazed frame with swing arm used; same engine and gearbox as 99; long roadholder forks and half width hubs; front tyre 3.25 x 19 inch
1958   88 and 99 alternator and coil ignition; Lucas RM15 alternator; cover over front engine plates where dynamo was previously located; Options included :twin carbs ; 9.0:1 pistons. Model 77 ends.
1959   new camshaft. Options: chromed mudguards


1960 De-Luxe models with enclosures slimline featherbed frame; rear enclosures on 88 De-Luxe and 99 De-Luxe, that required extra brackets on the frame. Original version known as De-Luxe since 1955 became the standard model; compression ratio increased to 8.1:1 for 88 and 7.6:1 for 99; twin carbs only available on standard model (too dificult to fit under enclosures). New dual seat for Standard and De_Luxe twins with locating pegs at the fron and spring gclip sat the rear. New silncers, new 3.6 gallon petrol tank with restyled tank badges
1960 88 Nomad
1960 Manxman USA only. 646cc Manxman introduced [68 x 89mm]; twin carbs with downdraft inlet tracts; 8.3:1 compression, tacho; magneto ignition; siamesed exhaust; high handlebars 3.25 x 19 front tyre; 4.10 x 18 rear tyre; chrome plated mudguards and chaincase.
92270 600cc Standard Aug 1960
92460 600cc De-Luxe Sep 1960
93235 500cc standard October 1960
93385 500cc De-Luxe October 1960
93601 650cc Nov 1960
    Speedo on all but 650 120mph (150kph); 650 150mph(180kph) optional on others. Options: Worked cylinder head for non SS models, dual carbs non De-Luxe models; high compression piston for non SS models; steering dampers on all; fully enclosed rear chain case on all; chrome mudguards on all standard models, tacho on all non SS models, racing footrest on all; folding footrest on all; folding kickstart lever on all; chromed front chaincase on all,


1961 Manxman available in UK and Europe compression ratio increased for 88 to 8.5:1 and 99 to 8.25:1; seat fastening at rear by quarter turn Dzus fastener. 646cc Manxman introduced [68 x 89mm]; twin carbs with downdraft inlet tracts; 8.3:1 compression, tacho; magneto ignition; siamesed exhaust; normal handlebars; same size tyres as other models; finished in two-tone grey, listed as "650". Options: chrome plated mudguards and chaincase; steering dampersl; air cleaners; fully enclosed rear chaincasel; tacho (rev counter) optional on all non SS models
96496 99SS March 1961 sports specials with tuned motors; twin carbs 1-1/16 inch; siamesed exhausts; ball ended levers; polished internals, hotter camshaft. Options included tacho and rear sets. Colours:two-tone grey.
  88SS March April 1961 sports specials with tuned motors; twin carbs 1-1/16 inch; siamesed exhausts; ball ended levers, polished internals, hotter camshaft, magneto ignition with manual advance. Options: tacho, rear sets, air cleaner. Colours:green or Dove grey.
  650 Oct 1961
  650SS 650 De-Luxe 650 SS and De-Luxe; all with downdraft inlet tracts; only 650SS with twin carbs; compression raised to 8.9:1; 88SS received the new head and compression raised to 9.5:1; magneto ignition with automatic advance. 99SS retained old style head with splayed ports and coil ignition; RM19 alternator on all models. SS models use Avon rear tyres. Options: air cleaner, tacho (650SS)


1962 Atlas 745cc motor [73 x 89mm] 7.6:1 compression; single carb; magneto ignition; smaller tank; raised bars; chrome plated mudguards standard;
97227 500cc De-Luxe ends August 1962
103392 99SS ends August 1962
103801 99 De-Luxe ends August 1962
103929 99 standard ends August 1962
104121 650 De-Luxe ends August 1962
101918 500cc standard ends Sept 1962
102911 500cc 88SS ends Sept 1962
104123 650SS Sept 1962
104267 650 Standard  


1963   De-Luxe models ends; 99 models ends;
  500cc 88 standard ends Sept 1963
  650 Standard ends Sept 1963


1964   Models are 88SS, 650SS, Atlas; wider fork leg spacing to fit wider tyres; 12v electrics; steering locks; Atlas - twin carbs. Options: alloy rims; rear chaincase
108000 First UK Atlas Feb 1964
109512 88SS introduced Sept 1964
110375 650SS Sept 1964
111377 Atlas Sept 1964


    wider rear chain 95/8inch x 3/8inch) all models
111920   Oct 1965. strengthened con-rods fitted 650Ss and Atlas
114870   Oct 1965. cylinder barrel spigot removed and new head gasket design; modified cylinde rhead to take short rockers. 650SS and Atlas


116372   Feb 1966. 6-start oiling system, 650SS +Atlas
116667   Mar 1966. short front fork tubes fitted C15CS
116966   Mar 1966 twin floats monobloc carburettor
117626   May 1966. valve insert diameter increased
118151 500cc 88SS ends July 1966
118252   June 1966. force fit studs for alternator
118752   Sept 1966. self lock nuts for force fit studs


1967   RM21 alternator; twin AMAL Concentric 930 carbs; matching speedo and tacho on plate between top fork nuts; light switch between instruments.
119760   650SS +Atlas
120323 N15CS May 1967
120572   Feb 1967. single dot roller bearing
121007   Feb 1967. Concentric carbs; 650SS +Atlas
121307   Mar 1967. capacitor ignition 650SS +Atlas
121665 P11 May 1967
121710   May 1967. P11 jets 250- 270 No air cleaner
122436   Jun 1967. Head bolts torqued to 240 in/lbs
123164 650 July 1967
123364   Aug 1967
123666 Commando Aug 1967
123672   Sep 1967. new rear portion front chaincase G15CS
124372 P11A Oct 1967. All P11A models: new type contact braeaker, street fork springs and damper, modified oil tank, low exhaust pipe, dual seat, rear lamp (new type), pillion footrests


1968   capacitor ignition system, dual set with hump; Atlas ends
124372 P11A Jan 1968
125780 Atlas ended Mar 1968
125871   Feb 1967. P11A long valves and short push rods first fitted
126124 650 Feb1968
126125 Commando Mar 1968. First Commando engine
128646 P11A Ranger Sept 1968. P11A new type sleeve gear and layshaft pinion first fitted
129147 Mercury Sept 1968 650SS renamed Mercury with one 930 Concentriccarb; no tacho; tacho optional. Options: stainless steel mudguards.
129145 Ranger ends Nov 1968
129892 P11A Dec 1968. P11A heat treated mainshaft washer first used
129897   Dec 1968. P11A security bolt fitted to rear wheel


1969   650SS renamed Mercury with one 930 Concentriccarb; chromed guards; no tacho; tacho optional. Options: stainless steel mudguards.


1970   Mercury ends
129894   Feb 1970
When is a Dominator not a Dominator? The Manxman (first 650) was referred to as a Manxman and not a Dominator. The Atlas was the Atlas 750 and not a Dominator.