Tiger Cub T20 (& T20J) 1958
Much carried on the same as the previous year for the T20 model with the exception of the appearance on some machines of a new Zenith carburettor, which over the tried and tested Amal carburettor, was found to give an increase in mid-range torque, improved acceleration up to a 60mph but with the loss of a little top speed.
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Also to appear was a new one-piece petrol tank badge to become known as the 'Mouth Organ' type, a smaller version of the one used on Triumph's larger machines. The famous Nacelle containing the black-faced 80mph speedometer, ignition and light switch, and gear indicator still remained. |
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Engine-wise a new duplex chain, engine and clutch sprocket sat in the primary chaincase; a much stronger item than the previous single row assembly. The colour scheme was still Crystal Grey and black (Aztec Red and black - USA models) although a larger silencer was to be seen fitted in an attempt to quieten down the Cub's growl. |
Interestingly a T20J 'Junior' Cub had been developed specifically for certain USA states where 14 - 16 year olds were allowed to ride motorcycles as long as the engine produced less than 5bhp. To effect the reduction in brake horsepower, a restrictor plate was fitted between the carburettor and cylinder head lowering the T20J's output to 4.95bhp @ 5700rpm. In every other detail the Junior model was identical to the full power Cub.
Specifications for 1958 T20 model
Engine
Type: Single-cylinder OHV, unit construction
Capacity: 199cc (12.1 cu in)
Bore/Stroke: 63mm (2.480in) x 64mm (2.520in)
Compression: 7:1
Power: 10bhp (7.5 kW or 10.1 PS) @ 6000 rpm
Carburettor: Amal 332/3 3/4in choke size or Zenith 17MXZ-CS5
Camshaft: Standard - valve clearances In & Ex 0.010in (cold)
Clutch: Wet multiplate
Gears: 4
Cycle Parts
Front Suspension: Telescopic forks, hydraulic damped
Rear Suspension: Swing-arm
Front Wheel: 16 inch (WM2 rim)
Rear Wheel: 16 inch (WM2 rim)
Front Tyre: 3.25 x 16
Rear Tyre: 3.25 x 16
Brakes: 5.5 in dia. Single leading shoe drum front and rear
Petrol Tank: 3 1/8 gallons (14.00 litres)
Oil tank - 2 3/4 pints
Gearbox - 1/3 pint
Primary chaincase - 1/2 pint
Front Fork: 1/8 pint
Electrics
Type: Lucas Ignition Coil
Voltage: 6
Charging Type: Alternator / Rectifier
Ignition Timing: 4 degrees BTDC static. 28 degrees fully advanced
Points Gap: 0.014in - 0.016in
Spark Plug: Champion L7 or equivalent
Spark Plug Gap: 0.025in
Specifications for 1958 T20 model
Engine
Type: Single-cylinder OHV, unit construction
Capacity: 199cc (12.1 cu in)
Bore/Stroke: 63mm (2.480in) x 64mm (2.520in)
Compression: 7:1
Power: 10bhp (7.5 kW or 10.1 PS) @ 6000 rpm
Carburettor: Amal 332/3 3/4in choke size or Zenith 17MXZ-CS5
Camshaft: Standard - valve clearances In & Ex 0.010in (cold)
Clutch: Wet multiplate
Gears: 4
Cycle Parts
Front Suspension: Telescopic forks, hydraulic damped
Rear Suspension: Swing-arm
Front Wheel: 16 inch (WM2 rim)
Rear Wheel: 16 inch (WM2 rim)
Front Tyre: 3.25 x 16
Rear Tyre: 3.25 x 16
Brakes: 5.5 in dia. Single leading shoe drum front and rear
Petrol Tank: 3 1/8 gallons (14.00 litres)
Oil tank - 2 3/4 pints
Gearbox - 1/3 pint
Primary chaincase - 1/2 pint
Front Fork: 1/8 pint
Electrics
Type: Lucas Ignition Coil
Voltage: 6
Charging Type: Alternator / Rectifier
Ignition Timing: 4 degrees BTDC static. 28 degrees fully advanced
Points Gap: 0.014in - 0.016in
Spark Plug: Champion L7 or equivalent
Spark Plug Gap: 0.025in