The Worst Bonneville? 1971 Triumph T120R

1971 was not a premium year for the Triumph Bonneville. It started with great promise, with the biggest redesign since the motor and transmission were made into one unit. The really large news was the new frame which carried the motors oil.

Problems started almost immediately for the ‘71. A brand new computer system led to parts shortages and very limited assembly numbers early in the model year. Once the frames were delivered the production line found that the motor couldn’t be inserted into the frame without removing the rocker boxes first, causing more delay. The total of the delays meant that the Bonnie was not very available in America prior to July which missed the best selling time of the season.

Then the design problems started to show up. Frames cracked at the center stand mount, which also happened to be the oil sump for the oil in frame set up. The new frame raised the seat height to 32” which meant only tall riders could really get both feet down. Oil capacity was actually reduced because of the location of the oil cap and dipstick under the front of the seat.

The good points for the ‘71 Bonnie included the stiffened frame with improved handling along with welded tubes that were smooth and strong. The brakes were upgraded to perform and look better. Four inspection ports appeared on the rocker covers which made checking valve clearance simple, A five speed transmission was an option.

The 1971 T120 R Bonneville used a 649 CC air cooled four stroke overhead design that made 50 HP with a 4 speed (standard) transmission and a total weight of 400 LBS. Suspension was telescopic front forks and the rear was a swingarm setup with Girling shocks. New design for the front and rear brake improved function and looks.

This particular 1971 T120 R is in Coombs, British Columbia, Canada. The bike is listed as “0 mile fully restored to stock”. It has a non stock two into one exhaust Two small items I noticed: I do not think the paint stripe on the tank is quite correct, and the “Made in England” script is missing from the right frame downtube. The bike is currently sitting on the starting bid of $9,000 Canadian ($6,712.91 US) with reserve not met and a Buy It Now price of S10,950 Canadian ($8,167.38 US)