The Triumph Thunderbird, build to fill a gap only Triumph knew existed, the 85 horsepower, 1597cc, parallel twin Triumph Thunderbird is a big-bore cruiser less over the top than a Triumph Rocket III but more substantial than the 865cc Speedmaster and America parallel twins at the opposite end of Triumph's cruiser range. Triumph say it's a big gap, especially in the Harley-Davidson dominated US.
The Triumph Thunderbird is all-new. At 1600cc it's the worlds largest parallel twin, with a 270 degree firing interval for offbeat lumpiness, liquid-cooling – the air-cooling fins are fake – and fuel injection to meet noise and exhaust emission targets, twin balancer shafts to damp the wrong sort of vibes, twin spark plugs for clean burning, an automatic decompresser to help turn over big 800cc pistons, twin-skinned exhaust pipes to stop the chrome bluing, six gear for a lazy overdrive and Triumph's first belt final drive since about 1920 – for low maintenance and to pander to American expectations undoubtedly.
The chassis looks as rudimentary as it can be – twin, preload-only shocks, steel tube cradle frame with the considerable mass of the engine as a stressed member, unadjustable 47mm forks and 310mm Nissin brakes with optional ABS. Steering geometry is well raked-out, closer to a chopper-like Harley-Davidson Fat-Boy than a lighter, less kicked-out H-D Street-Bob. Nonetheless, Triumph are explicit in their claims for the Thunderbird cornering – it has, they say, 'the handling capability to be ridden enthusiastically.' Funny thing is, they're right. Cruiser handling characteristic are a given; long wheelbase, lots of weight, low seat height and easy-going geometry dictate slow and over-stable steering that, once mid-corner, is reluctant to change. Besides, ground clearance is usually so poor that suspension assessment is limited to ride quality rather than keeping the thing pointing in the right direction.
So it's a pleasant surprise to find that while ground clearance is obviously, restricted, the Triumph Thunderbird responds to steering input less like a cruiser and more like a long, low tourer. You can roll off the throttle and change line mid-corner without upsetting the plot, which means you don't need to plan your line and speed as carefully as you do on a Harley-Davidson. With similar weight and steering geometry figures to a H-D Fat-Boy, Triumph say the difference is mostly down to careful selection of tire profile – the Triumph Thunderbird wears new Metzeler Marathons, developed alongside and tested on the Thunderbird.
And then there's the engine, which doffs away agreeably, turning over at 2750rpm at 130 km/h in top. You need to cog it down to make a hurried overtake, but again the truly memorable characteristic is the control the rider has – fueling is faultless, allowing the tiniest feathering of the fat throttle grip to tug the engine from 40 km/h in top with booming great thuds from the pistons spinning at a relaxed pace.