Tanshanomi's Snap Judgments

Triumph TSS

Thu, May 27th, 2010

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Featuring a different Triumph street bike each day.

1982–83 Triumph T140W TSS
The efficient but fragile 8-valve head and new crank fitted to the TSS's otherwise-standard Bonneville motor transformed it into a smoother, quicker-revving, more eager motor without losing any of the traditional qualities that Bonnie riders had come to love. Like all Bonnies of the era, it featured electric starting and electronic ignition that were reliable and robust.
It was a standard Bonnie chassis, and inherited that bike's strengths and shortcomings.
The late Bonnevilles were well-detailed, and what the TSS shares with them is beautiful. But the 8-valve head that makes it unique had little of the sculptural grace of the original.
The Westlake-sourced top end was originally designed in the '70s as a racing head, and it was not up to the level of quality required for a production bike. Castings were notoriously weak, which lead to catastrophic failures that surprisingly had nothing to do with the four-valve-per-cylinder valvetrain itself. It was a great design let down by poor execution. A pity, really.
They are highly sought after (and therefore very expensive), very unreliable, and parts are scarce. Each TSS is an irreplaceable historical artifact best left to museums and concours collections.
The very last and most exotic Triumph model to leave the Meriden plant before it closed. Only a few hundred were made.
It could be considered the ultimate, most highly evolved 'real' Bonneville, or the last gasp of a faded marque long past its prime. It is probably, in some way, both.