|
Make Model |
Triumph
Bonneville 650 T120 |
|
Year |
1972-73 |
|
Engine |
Air cooled, four stroke,
parallel twin, OHV |
|
Capacity |
649 |
|
Bore x Stroke |
71 x 82 mm |
|
Compression Ratio |
8.5:1 |
|
Induction |
2x Amal |
|
Ignition /
Starting |
- / kick |
|
Max Power |
46 hp @ 6700 rpm |
|
Transmission /
Drive |
4 Speed /
chain |
|
Front Suspension |
Telescopic forks |
|
Rear Suspension |
Swinging arm |
|
Front Brakes |
Drum |
|
Rear Brakes |
Drum |
|
Front Tyre |
3.25 -19 |
|
Rear Tyre |
4.00 -18 |
|
Weight |
175 kg |
The 1971 Triumph Bonneville was the problem child of
a shotgun marriage. It was responsible for Triumph missing that year’s U.S.
sales season, and it just about bankrupted the company.
The late Sixties Triumph Bonnevilles were, and still are, considered to be the
best of the lot. But a major program of standardization was underway across the
BSA Group, which also owned Triumph. For the 1971 season, BSA planned to use a
new oil-bearing frame for both BSA and Triumph 650 twins.
However, the new Triumph frame had been designed around the BSA 650 engine, and
when the first batches of frames were delivered to Triumph’s Meriden factory,
assembly line workers found they couldn’t fit the Triumph engine in the frame
without removing the rocker boxes from the cylinder head first.
The 1971 Bonnies were already behind schedule because of production delays
caused by a shortage of parts — the result of teething troubles with a new
computer system. The cumulative result was that very few Bonnevilles were at
U.S. dealers for the critical April to June sales season. Other problems with
the 1971 bike included a seat height only suitable for people over 6 feet tall,
major frame failures caused by the center stand being mounted on the oil-bearing
“sump,” and aesthetics only a short-sighted mother could love. The 1971 model is
perhaps the least popular of all Bonnies.
