The difference between the new Triumph Bonneville Street Twin and the previous Bonneville is only one thing: everything. It has a new engine, new chassis, new instruments, new fly-by-wire throttle, new traction control, new yadda, new razzmatazz, and new glafuncles. But sure, it’s hard to see changes on a bike that is an updated retro design that’s equally as retro as the previous retro version. So, the Street Twin’s new is a new that’s supposed to be felt, not seen. You will be able to feel it. The Street Twin engine is a liquid-cooled, eight-valve, single overhead cam, parallel twin with sleeveless Nikasil-coated cylinders and a 270° crank angle. Plus, it’s now actually 900cc, not 865cc. This new powerplant has redefined performance parameters, with a claimed 55 rather than 67 horsepower, and 59 versus 50 pound-feet of torque. At a glance that might seem odd to give up so much horsepower. But it’s not odd. It may be initially disappointing considering the significant update to the platform, but if it’s higher performance you are after, Triumph will refer you to the new bigger Bonnevilles.Please enable Javascript to watch this video
The engine has two counterbalancer shafts, one front and one rear, and each, of course, spins in the opposite direction of the crankshaft. Peak horsepower is at 5,900 rpm, and redline is somewhere just beyond that. For a liquid-cooled motorcycle, the Street Twin has efficient air-cooling fins on its head and cylinders. In other words, these fins don’t fib: they actually do assist in cooling the engine. The transmission has five speeds. The EFI feeds through a single 39mm throttle body. By comparison, the Indian Scout 60, at 1000cc, has a 60mm throttle body. Considering that twice a diameter is four times the volume, these numbers are quite far from each other. Also, considering the Venturi effect, which defines how a constricted path results in a lower pressure yet higher velocity of flow, there’s a significant engineering disagreement here between these brands. The Street Twin’s fuel management design results in increased fuel efficiency for a claimed 72.8 mpg at a steady rate of 56 mph, and 52 mpg at 75 mph. What we did verify so far is that when the bike is ridden hard for extended mountain miles in second gear, dragging toes through the turns and railing up to redline in the short straights between each of them, our mileage was 47.3 mpg, which is very impressive. Very. This shows that the Street Twin achieves a totally plausible range with its small, 3.2 US gallon, tank, that under normal use should exceed 200 miles per tank.
The Bonneville Street Twin’s chassis is steel tubes welded to a cast-iron steering head, bolted to an engine cradle. Rake is 25.1 degrees and trail is at 4.0 in (102.4 mm), which are common numbers. The suspension in front and rear is by Kayaba, with a 41mm conventional fork up front, and preload-adjustable twin shocks in the rear. Both ends have 4.73-inches of travel and the shocks are set up with ample sag and have progressive springs, for a soft initial travel. The wheels are cast aluminum: 18 x 2.75-inch front, 17 x 4.25-inch rear, with classic-looking Pirelli Phantom tires made to Triumph’s specs. The tires are 100/90-18 front; 150/70 R17 rear. Braking at each end is by single Nissin 2-piston floating calipers, mated to a 310mm disc up front and a 255 mm one out back. ABS is standard. Seat Height is 29.5 in., and the claimed dry weight is 437 lbs.
Other features include Traction Control that can be turned off, ride-by-wire throttle, security immobilizer, and a USB socket under the seat. The hand levers are adjustable. A single round gauge contains an analogue speedometer and a multi-functional LCD display shows gear position, fuel level, range-to-empty, fuel consumption rate, traction control status, service indicator, clock, and odometers. The gauge choices are scrolled with an “i” button on left handlebar. On the right handlebar is a nifty, combined start/kill switch, plus a four-way flasher button. Already Triumph offers over 150 accessories for the Street Twin, including bags, billet parts, exhaust, and gear.
The Bonneville Street Twin’s class of motorcycles might be best described as the mystery-of-the-missing-horsepower class, defined by bikes with full-sized meaty engines blessed with mid-sized mild performance. It’s a retro-ish, roadster-ish, twin-ish class that includes the likes of Harley-Davidson 883 Sportster, Indian Scout 60, Yamaha Bolt, Moto Guzzi V7, Scrambler Ducati, and this Street Twin; maybe one or two others. This niche is now a full-on market center of easy-to-ride yet totally capable motorcycles. Oh, and each bike must have a base model costing less than $9,000, even if it’s only one-dollar less. The aging generation of performance motorcyclists have been long drunk on horsepower as the end-all measure of performance and happiness. But the Street Twin is for a new crowd who value a ride of quality and ease. Triumph providing ABS and traction control as Street Twin standard features, on an otherwise retro bike, is no accident, pun fully intended. With the Street Twin, its engine to horsepower ratio isn’t a matter of dumbing down a beast. A big twin allows the creation and manipulation of a crafted powerband that’s broad and smooth from bottom to top, making the most of the plateau of torque rather than chasing the peak of horsepower. The omission of a tachometer isn’t for keeping costs down, it’s to make a statement because the specific location of redline just doesn’t matter.
Chasing horsepower is a nervous activity and this bike is designed to be calm. Also, hp is a measure over time and its peak number only exists for an instant at the top-end of a revving journey. Most riders never go there, don’t want to go there, and don’t know why anyone would think of going there. The Street Twin has traction control, and EFI and so its system always knows damn well exactly what rpm the engine is at; but there’s no reason to bother the rider with that information. And, anyway, it’s a soft redline. Initially. A couple Triumph personnel mentioned that it Triumph is an engineering company, above all else. So, does the Street Twin show that? Yes it does. This bike’s efficiency of travel, both in miles per gallon and in suspension movement, defends this engineering claim. So does the Street Twin’s virtually vibration-free chassis, despite the fact that the engine is hard mounted with no rubber dampers. Even when running up into redline it was rock smooth, very unlike at least one other bike in its class that gets all jiggy at 5,400 rpm. Its fuel efficiency means that the Street Twin’s small tank can provide over 200 miles of travel, which is far more than the Indian Scout 60. Your mileage may vary.
On the Street Twin, the ride is soft, the seat is soft, the power is soft. Overall, the chassis is well controlled with properly tuned damping for both high-speed and low-speed suspension movement, though it can get a bit overwhelmed when pushing through sweepers at terminal speeds. But, as hinted above, no one desiring this bike plans on riding like a knucklehead. If the Street Twin is vying for the prize of friendliest street bike ever, it is certainly a formidable contender. And we’re not talking about little bikes with little engines; we’re talking about serious bikes that can be ridden any distance, exceeding any popular touring speed, and be very cool to own and trust and love. Something that Triumph has as a brand is character, and there’s no extra cost for that. Many of its employees have been there since the company reopened in the 1980s, with most of those who left merely retiring. It’s a family—a British family primarily—and they’re proud that they don’t compete with others but do it their own way. MSRP for the 2016 Triumph Street Twin is $8,700 for jet black. All other colors Phantom (metal flake) Black, Matte Black, Aluminum Silver, Cranberry Red: $8,950.
By Cycle World
