1961 TRIUMPH TR6 BY THE NUMBERS
Gone was the previous “A” & “B” designations introduced in 1960. The new nomenclature was TR6R for ‘Roadster’ with low pipes & TR6C for ‘Competition’, the enduro version with high pipes. All went by the model name “Triumph Trophy”. 1961 Triumph TR6 engine & frame numbers run from D8432 to D15756, built from Sept. 20, 1960 to Aug. 23, 1961. For 1961 the Triumph TR6 was not listed for sale in the UK.
ENGINE MODS
In the interest of quieter operation, starting with Engine #D8858 a new alloy ‘Delta’ cylinder head was fitted with cast-in pillars between some of the cooling fins, to combat high frequency vibration causing a ‘ringing’ sound. Starting with Engine #D14438 the one-piece forged steel crankshaft now featured straight-sided webs & the central flywheel was increased in width from 2-1/4″ to 2-11/32″. The balance factor now changed from 50% to 71%. Finally, the engine sprocket reduced to 21 teeth, lowering the overall gearing of the bike. In the gearbox, the sintered bronze layshaft bushings (bushes) were replaced with Torrington M11121 needle roller bearings.
DUPLEX FRAME PROBLEMS ADDRESSED
Within months of its launch in 1960, the new Duplex Frames were cracking around the steering head. The factory quickly addressed it & 1960-model bikes were retrofitted by dealers with an additional bracing tube under the backbone, all under warranty. Now, the 1961 Triumph TR6 & all other Triumph motorcycles sharing the duplex frame, got the additional bracing tube installed at the factory. Interestingly, most of the frame cracking problems were in the US & were later attributed to the brutal punishment the bikes were forced to endure in off-road racing.
1961 Triumph TR6 SPECIFICATIONS
|
TR6R Trophy TR6C Trophy Engine type Displacement Bore & Stroke Compression Carburetor Ignition Engine output Primary drive Primary sprockets Clutch Gearbox Ratios, overall: 1st, bottom 2nd 3rd 4th, top Final drive Final drive sprockets Frame Type Suspension, front Suspension, rear Brake, front Brake, rear Tire, front Tire, rear Wheelbase Seat Height Ground Clearance Fuel capacity Dry weight |
Roadster (low pipes) Street Scrambler (high pipes) Air-cooled OHV vertical twin, non-unit 649cc / 40.0 ci 71mm X 82mm / 2.79″ X 3.23″ 8.5:1 (US & export); 7.0:1 (UK) 1-Amal Monobloc Lucas magneto 42 bhp @ 6500 rpm 1/2″ X .335″ X 5/16″ chain, 70 links 21T X 43T Multi-plate, wet 4-speed constant mesh, right foot shift 11.92:1 8.25:1 5.81:1 4.88:1 5/8″ X .400″ X 3/8″ chain, 101 links 18T X 43T Brazed lug, rigid Telescopic fork, hydraulic damping Swing arm, 2 Girling dampers 8″ SLS drum 7″ SLS drum 3.25″ X 19″ Dunlop 4.00″ X 18″ Dunlop 55.25″ / 140 cm 30.5″ / 77 cm 5″ / 12.7 cm 3 Imp gal (US); 4 Imp gal (UK & export) 380 lbs / 173 kg |