Thunderbird Twinspark is aimed at consolidating Royal Enfield’s market position and underlines the company’s realisation of the youth segment’s potential as consumers. There is no apparent change in chassis design as the new UCE (Unit Construction Engine) is a perfect fit for the tried and tested Bullet frame. The body panels and tank also remain the same as its predecessor’s.
However, there are small but notice able changes in some of the details. The fuel tank now fits neatly on to the chassis without any metal protrusions beneath. Weld lines are neat and uniform. The front mudguard, headlight and instrumentation clusters are the same as on the old Thunderbird. No two-tone paint scheme or garish stickers for the fuel tank nor for the side panels. The chromed pillion backrest on the one piece stepped seat, unlike the previous version, is not just a turned and twisted steel rod but is a well designed piece.
There are two Twinspark badges on the side panels and a decal on the pillion backrest but there’s no mention of the UCE. The ergonomic shortcomings of the out going Thunderbird are mitigated some what with the provision of foldable front footrests which help in hauling the 168kg bike on to the centre stand. To save metal and transmission losses, the chain sprocket and chain are now located on the right hand side as is the entire rear brake assembly. As a result, the left side of the bike looks plain and characterless.
The UCE’s square-edged design takes some getting used to, though. The engine’s matte silver finish feels less susceptible to rust and corrosion. The big 19-inch steel spoke wheels are true to the cruiser tradition and are fitted with the usual MRF crossplys. The bike feels stable at speed though vibrations are a bugbear. This Thunderbird holds its line during hard braking. The Thunderbird Twinspark front disc brake and drum at the rear provide sufficient bite, the bike comes to a standstill steadily and faster than the outgoing version.
Ride quality has never been a Bullet forte and the Thunderbird Twinspark is no exception. The wide seats and comfortable riding position ensure fatigue free tiding. With its raised handlebars and front-set footpegs, this is hardly the tool for fast cornering. But the kick lever takes some muscle to prod and is (as usual) awkwardly positioned. Thank god for electric start, then. The cast iron engines paved the way for the lean burn engines. As the name suggests, the new UCE integrates the engine, gearbox and clutch. The new set-up is a little more efficient thanks to the omission of a heavy drive chain. The integration of the engine and gearbox was done in-house. The engine has been tuned by European design consultants in the NVH (Noise, Vibration and Harshness) context.
Royal Enfield calls this new engine platform the ‘engine of future growth’. With the UCE, RE aims to bump up the Thunderbird’s reliability. The valve clearance of the UCE for instance adjusts automatically through the use of hydraulically controlled pushrods and thus optimal valve timing is maintained in all situations. Another notable feature in the Twinspark is the auto decompressor which activates at 250rpm to put paid to start up woes. The electric motor is placed on the inner side of the UCE engine to reduce characteristic sprag clutch glitches.
The new UCE features a superior trochoid rotary pump which pumps oil at higher pressure and ensures better cooling. This results in better efficiency and reliability. This new engine cranks out 19.3PS of maximum power at 5250rpm and 28Nm of peak torque at 4000rpm. The all-new 6-plate clutch requires little effort to oper ate. The engine offers spectacular low- end torque, but the top end feels weak. Credit is due to the five-speed transmission that ensures the Thunderbird is so useable.
The engine revs up to 5500rpm without strain. The Twinspark gets to 6okmph from standstill in 5.8 seconds, nearly a second faster than the previous generation Thunderbird. 1 managed a top speed of lo9kmph. I do wish the engine vibes were better controlled, though. The Thunderbird Twinspark returned 42kmpl on our combined city and highway run, and cruising at a constant 90kmph is well on its agenda. Engine noise level is similar to the AVL engined version.
The Twinspark will sport the bazooka silencer which will tone down the thump considerably. But Royal Enfield will offer an aftermarket exhaust that will release the thump and make the engine noticeably smoother. The old iron block engine is still the favourite of Bullet aficionados mainly because of its thump. But superior technology and better reliability are aspects no bike maker can afford to ignore. The cruiser styled Thunderbird turned the eyes of the younger generation towards Royal Enfield bikes.
The Thunderbird Twinspark is lighter and more fuel efficient than any other Royal Enfleld bike. With a fuel injection engine ready to go on sale in Europe, Royal Enfield seems keen on increasing its market share. The Thunderbird Twinspark costs over a lakh of rupees how ever, which is definitely not within every one’s reach. The Thunderbird Twinspark however marks Royal Enfield’s entering a more technology oriented arena.