The 1959 Triumph Bonneville T120 from United Kingdom was powered by a 649cc OHV twin producing 46hp at 6500rpm. Weighing 172.0kg (379 lbs) and with a seat height of 790mm, it was aimed at standard riders.
The 1958 Norton Dominator 99 by contrast offered 597cc of OHV twin power, delivering 31hp at 6000rpm. Tipping the scales at 182.0kg (401 lbs) with a top speed of 155km/h (96 mph), it offered a distinct riding experience. 1950s bikes represent the golden age of British motorcycling and early Japanese innovation, with well-maintained examples commanding premium prices.
Specifications Comparison
| 1959 Triumph Bonneville T120 | 1958 Norton Dominator 99 | |
|---|---|---|
| Displacement | 649 cc | 597 cc |
| Power | 46 hp | 31 hp |
| Torque | 52.0 Nm | 40.0 Nm |
| Cylinders | 2 | 2 |
| Top Speed | 177 km/h | 155 km/h |
| Quarter Mile | — | — |
| Dry Weight | 172.0 kg | 182.0 kg |
| Wet Weight | 185.0 kg | 195.0 kg |
| Seat Height | 790 mm | 790 mm |
| Wheelbase | 1400 mm | 1400 mm |
| Fuel Capacity | 14.0 L | 14.0 L |
| Gears | 4 -speed | 4 -speed |
The Verdict
For pure standard performance, the 1959 Triumph Bonneville T120 has the edge thanks to more power (46hp vs 31hp) and a higher top speed and lower weight. The 1958 Norton Dominator 99, however, excels when all-round versatility and everyday riding is the priority. For collectors, the 1959 Triumph Bonneville T120 commands more attention with a 9/10 collectibility rating. Parts availability is good for the 1959 Triumph Bonneville T120 and moderate for the 1958 Norton Dominator 99 — an important factor for any restoration project.
About the 1959 Triumph Bonneville T120
The 1959 1959 Triumph Bonneville T120 packs a 649cc OHV twin engine with 46hp into a standard motorcycle package from Triumph.
Full 1959 Triumph Bonneville T120 Profile →About the 1958 Norton Dominator 99
Introduced in 1958, the 1958 Norton Dominator 99 features a 597cc OHV twin engine producing 31hp, establishing itself as a notable standard motorcycle.
Full 1958 Norton Dominator 99 Profile →