Triumph Bonneville T100 Twin 2001-2007 Service Manual

Wikipedia's own production data confirms the T100 ran 790cc from 2002-2004, then stepped up to 865cc from 2005 onward — the same displacement progression shared across the T100, America, and Speedmaster during this era, all built at Triumph's Hinckley, Leicestershire factory. Where the America and Speedmaster leaned into cruiser styling, the T100 stayed genuinely closer to the standard Bonneville's classic roadster silhouette, with the "T100" designation itself tracing back to Triumph's own historical naming for a 100mph-capable Bonneville — a genuine performance claim rather than just a trim badge.

Power comes from an 865cc air-cooled DOHC parallel-twin with a 360-degree crank (a genuinely different firing character than the 270-degree twins used in the America and Speedmaster), a 90mm x 68mm bore and stroke, delivering a claimed 61-67 hp at 7,400 rpm through a 5-speed gearbox with chain final drive, reaching an estimated 115 mph top speed. That 360-degree crank gives the T100 the smoother, more evenly-spaced firing pulses of a conventional parallel-twin, distinguishing its character from its 270-degree cruiser siblings and keeping it closer in feel to the classic Bonnevilles Triumph built decades earlier.

Styling stayed genuinely faithful to the original Bonneville's proportions throughout this span: a round headlight, chrome-trimmed instrument cluster, wire-spoke wheels, twin exhaust pipes, and a genuinely classic teardrop fuel tank — the T100 deliberately positioned as the more "authentic" heritage model within Triumph's modern lineup, versus the America's dedicated cruiser stance or the Thruxton's café-racer treatment sharing the same fundamental engine platform. Seat height sits at 30.5 inches (770mm), with a 59.1-inch wheelbase and dry weight around 451 lbs (205kg) — genuinely lighter than the cruiser-oriented America thanks to the more upright, standard-style ergonomics and reduced touring equipment. A 3.5-gallon (16-litre) fuel tank rounds out the package. This carbureted-era T100 ran through 2007, sharing its fundamental 865cc engine architecture and 5-speed driveline with the other Bonneville-family models of the period, before Triumph introduced fuel injection across the range starting in 2008.

This factory service manual covers the procedures, torque specs, and diagrams needed to keep a 2001-2007 Bonneville T100 running the way it was built to.