TRIUMPH JT SPECIAL
This T140v-based replica of Triumph’s Us-export TT Special sounds like a hooligan and rides hard – but it’s also in touch with its feminine side
Think gutsy and useable TT Special replica, only finished with a truly personal touch
At a glance, the side-panel lettering appears to say ‘TT Special’, but it actually reads ‘JT Special’ and the ambiguity is intentional. This stunning Triumph is the latest work of professional metal worker John Tarplee, whose 750cc Bonneville T140-based specials have been featured before in Classic Bike. It is his partner Natalie’s bike, a 1978 Uk-market T140V bought seven years ago in near-standard trim and running badly. Now it has been rebuilt in the mould of Triumph’s iconic 650cc TT Special competition twin which was shipped to the North America market from 1963 to 1967 – but with cosmetics and details to suit Natalie.
“I didn’t want it changed too much. Just prettified and a little bit girlie,” says Natalie, a school physics lab technician. “I love my Bonneville because it’s quite low. I had a Suzuki DR400 that was far too tall, so I didn’t feel confident stopping at junctions or on a steep camber. I also had a Yamaha XS650, but I found that too heavy.”
The most obvious feminine touch is the sparkling paintwork on the stock T140 fuel tank. The design was arrived at by John roughing-out schemes with spray cans and lining tapes in consultation with Natalie. Once the scheme was decided, the tank was given to Dave May (07584 192562) to apply paint and lacquer professionally. Gold-edged purple stripes swirl against a metallic black base colour and, unusually, the left and right sides of the tank are not to the same pattern. “As Nat liked two designs, we thought why not have them both?” John says.
While undoubtedly pretty, this Bonnie also has raw functionality and sharp performance worthy of a TT Special. Magnificently grunty and bursting with torque, the engine is a five-speed, left-foot-change unit assembled by John using his intimate knowledge of the T140. There’s phenomenal arm-tugging pull from low rpm, with a crisp throttle response that makes tearing along twisty roads a joy. Gear selection is slick and the basically standard brakes work well, with decent bite up front and a softer feel at the rear. The Avon Roadrider tyres make for confidence when pitching into tightening bends or crossing patchy road surfaces on rural roads near the couple’s Worcestershire home. The T140 oil-bearing frame, evolved from the unloved P39 frame introduced by both Triumph and BSA in 1971, was one of the best handlers of its day. Being around 20% lighter than the stock 1978 T140 at 163kg (359lb) at the kerb, this Bonnie feels nice and ‘chuckable’.
You wouldn’t know it from the rip-snorting exhaust sound, but the elegant swept-in TT track pipes do have baffles. They fit inside slip-on tailpipes retained by tension springs and angled to splay apart slightly, rather than pointing at the rear tyre like the originals. The downpipes have redundant bosses where stays would attach them to the TT Special’s pre-1971 single-down-tube frame, but they are not obtrusive. The high, rubber-mounted handlebars are equipped with user-friendly modern switch clusters and the TT’S trademark centrally-mounted rev counter is replaced by a multi-function Motogadget instrument. Its analogue dial indicates rpm, calibrated up to 8000rpm, while road speed appears in an LED window that also shows oil pressure, via a plumbed-in sender unit, and battery voltage. Various other functions are available and parameters are set using the headlight flasher button on the left-side switch console.
The tidy look is helped by the absence of an ignition switch, thanks to Motogadget’s contactless system. The electrics are turned on by placing a coin-sized transponder disc close to a computer-style on/off symbol sticker on the right-hand side-panel, behind which is the switch. Custom stickers, including the JTS tank emblems, were obtained from Absolute Control Signs & Graphics (01386 553657).
Indicators are almost indispensable for brisk riding in today’s traffic, but can spoil the lines of a lean machine like this, so John came up with a neat solution. He glued strips of orange LED lights to rings cut from plastic tube that fit over the front fork tubes just above the bottom yoke and the tops of the Ikon Dial-a-ride rear shocks. Unobtrusively wired to a flasher unit under the seat, they operate from the left ’bar. A Cibié sealedbeam halogen unit is housed in the chromed headlamp
‘I DIDN’T WANT IT CHANGED TOO MUCH. JUST PRETTIFIED AND A LITTLE BIT GIRLIE’
shell and a Vincent-type rear light with ‘STOP’ lettering is fitted at Natalie’s request. The handlebar grips are the barrelled cushion type seen on the standard T140 and a rear-view mirror is mounted on the right ’bar.
“It’s all in the pads,” John says about the effective disc brakes. His choice is EBC’S HH grade with a goldcoloured friction surface. The small handlebarmounted front master cylinder and its lever are generic modern items, while the hose from the rear cylinder has been re-routed for tidiness; the original arrangement was hidden by the right-side silencer.
The wheels were built by the Devon Rim Company with XS alloy rims, 19in front and 18in rear, shod with 100/90 and 120/90-section tyres respectively. Polished alloy mudguards follow TT Special style. The minimal-looking seat is more comfy than it looks; John made the base for upholstering by P&P Seating (0121 784 4001) whose one-off service is a speciality. The moulded sidepanels are aftermarket items designed to give a slim 1960s look to post-1970 oil-in-frame Triumph twins.
The bike was bought ‘at the right price’, but had a sticking swingarm, ran roughly and rattled. “When
I stripped the engine, it looked as though it had been thrown together from a shed-full of bits,” John says. “The previous owner had paid for a so-called professional restoration and was disappointed.” The unit was rebuilt after SRM (01970 627771) dynamically balanced the crankshaft, with rebored cylinders, 8.6:1 pistons and a Morgo plunger oil pump. The cams responsible for strong low-down and midrange urge are a half-race grind from Triumph parts specialist KBH Motorcycles (01752 896477). The valves, valve seats and guides were fitted by Cylinder Head Shop (01507 328590). This head is from the final year that Uk-market T140 engines had splayed inlet ports; a revised head with parallel inlets and non-spill Amal Concentric MKII carburettors adopted for the Us-market T140E in 1978 was used in other markets from 1979. Natalie opted to keep non-standard chrome plating on the carburettor tops, floatbowls and inlet stubs, in place when the bike was bought. Primary drive to the stock five-speed box is by a belt kit from Burton Bike Bits (01530 564362).
A lithium-ion battery, charged by a high-output 200-Watt alternator supplied by Paul Goff (01494 868218), powers the Boyer Bransden electronic ignition. The coil, also from Goff, has both HT leads emerging at one end and is mounted under the front of the fuel tank along with an attractive finned alloy heat sink milled from solid by John.
Riding this taut, get-up-and-go twin, I’d never have guessed that two gaskets are sandwiched between the head and barrel to soften the compression ratio and make kick-starting easier. I suspect this helps to make the engine so tractable – high compression is not necessarily the best way to go. Natalie says she has no trouble kickstarting, unless people are watching. I know how she feels.
‘THE ENGINE LOOKED AS THOUGH IT HAD BEEN THROWN TOGETHER FROM A SHED-FULL OF BITS’
ABOVE: Natalie with her bike and the man who built it for her, partner John Tarplee
ABOVE: Light and nimble Bonnie is just the job for chucking round local B-roads BELOW: A cool and compact set of wheels any girl would be proud of