Vic Shield’s T140 Bobber…
In the early 1970s, Triumph replaced the storied 650cc T120 Bonneville with the larger capacity T140. The bike was originally 724cc but quickly bored to 744cc, and retained the oil-in-frame / dry sump design of its predecessor. Though the T140 was originally intended for export only, there was so much interest in a 750 Bonneville that Triumph decided to offer the machine in their home market as well.
Until 1983, the T140 Bonneville kept the British banner flying in the motorcycling world. Speaking specifically of the T140, Classic Bike Guide perfectly describes the charm of these oil-in-frame twins:
“A Bonnie is a comfy, rapid classic that can lope along all day, stop when you ask it to and blast off into the middle distance occasionally when you open the taps. Find a good A-road and give the big twin a handful and it’ll shoot off like an elderly but over-excited labrador getting the scent of a rabbit.”
Of course, the 750 Bonnie you see here is no stocker. It comes from our old friend Vic Shield of Vic’s Custom Autos. We’ve featured a handful of Vic’s builds in recent years. You might recall his
Yamaha “RD375LC” street tracker or RZ421-Powered “Mutant” MZ Skorpion — wild smokers in a class their own.
Vic has had a few health issues, but now he’s back on track and just finished a long-term project in the form of this Triumph “ex-bobber.” A friend of Vic’s bought the bike as a poorly-built, downright dangerous hardtail bobber in dire need of a total rebuild…and of course it ended up in Vic’s hands.
“In hindsight it should have been sold and left alone…taking on someone else’s project is the best way to lose money and what hair I had left on my noggin.”
Below, Vic describes the triumphs and travails of redesigning and rebuilding this Triumph bobber. He’s done a fantastic job of creating something quite distinctive and lovely, with modern touches that don’t upset the old-school, almost steampunk charm.
Bravo, Vic! We’re glad to see this old Trumpet reborn, even if it might’ve cost you the last of your hair!
In the Builder’s Words…
The bike was brought by a mate as a badly-assembled bobber based on a T140 Bonneville. It had drum brakes front and rear that looked like they were off a moped and didn’t stop a bike of this size. The Triumph frame had been hard-tailed and the alignment on the chain and wheels wasn’t excellent either; basically it needed a rebuild. In hindsight it should have been sold and left alone…taking on someone else’s project is the best way to lose money and what hair I had left on my noggin.
The bike was stripped and a set of upside down forks sourced with a disc brake. Think they were KTM. A hub was laced to a 19″ aluminium rim and an adapter plate made for the disc. What I didn’t want was the front end to look too modern.
The rear wheel was a different story. This put the bike on hold for ages. I had lost the will to live trying to make the fat 5″ wide bobber style wheel and tyre fit that my mate wanted to use. The chain kept rubbing the various tyres and whatever route I went down just didn’t work with the 16″ rear rim and tyre.
After a cooling off time, I changed the rear for a narrower 17″ rim and old school tread pattern tyre.
This worked and gave me enough clearance on the frame and chain.
Now on the British bikes up till the late 70s the rear brake and gear lever were on the opposite sides to the rest of the motorcycling world…this is where another problem arose. I had to somehow link the brake pedal to the large rear drum brake off a mid 70s Yamaha. I fabricated some brackets that were welded to the frame to take a brake cable from a 70s Suzuki Beamish and this solved the issue of transferring the brake pedal on the left to the brake drum on the right.
Electrics are powered by modern battery in a hollowed-out Lucas battery case and a fuse box tucked away under the seat. An electronic ignition system by Vape produces the sparks and the front light is off an old vintage car from we think the 1920s. Hardest part of the electrical work was fitting the new Smiths electronic clocks, which had more wires than really needed and each wire was the size of a hair…not a nice job.
The original tank was kept as it didn’t leak and the previous owner had made it fit the frame doing away with the mid-mounted bolt that runs through the centre of the tank.
The seat unit I fabricated from steel and used half a leaf spring and a small shock as a way to get away from that hardtail ride.
It’s painted in old English white, a colour that Jaguars used back in the early days.
To feed the engine a pair of Amal 30mm Mk2 Concentric Carburettors were added and I made a pair of stainless inlet trumpets to aid airflow into their mouths.
A series of stainless steel exhaust sections were welded together and snaked around the frame and engine finishing into a shotgun non-silencer. This does sound crisp while not annoying the neighbours at 7am.
I expect there will be teething issues as there always is with special one-off builds, but it does pull well and grabs quite a bit of attention when it’s parked up amongst the sea of multi-coloured plastic at a bike meet.
It’s a ex bobber special….not everyone’s cuppa but it’s certainly in a different class.
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More from Vic’s Custom Autos
Street Triple on Steroids: Triumph Trophy 1200 Streetfighter - Vic Shield’s Trophy 4 Streetfighter, built 28 years ago! The modern rebirth of the Triumph brand is a storied one. In 1988, a new factory was built on a 10-acre site in Hinckley, Leicestershire, and […]
Ex-Bobber, Reborn: Triumph T140 Bonneville Special - Vic Shield’s T140 Bobber… In the early 1970s, Triumph replaced the storied 650cc T120 Bonneville with the larger capacity T140. The bike was originally 724cc but quickly bored to 744cc, and retained the oil-in-frame / […]
Royal Enfield Bullet 500 with Alloy Sidecar - Vic Shield’s Bullet 500 with bespoke aviation alloy sidecar… With their first machine launching at London’s Stanley Cycle Show in 1901, Royal Enfield can lay claim to the title of the world’s oldest motorcycle brand […]
Hooligan’s Dream: Yamaha “RD375LC” Street Tracker - FLATTY: Vic Shield’s 375cc Two-Stroke Street Tracker… By the late 70s, Yamaha’s air-cooled RD250/400 two-stroke street bikes were due for an update. In order to galvanize the supersport class, Yamaha decided to go all-out, creating […]
The Mutant: 421cc Two-Stroke Skorpion! - Vic Shield’s RZ421-Powered MZ Skorpion! In 1994, former East German motorcycle maker MuZ — aka MZ — introduced the Skorpion, a single-cylinder sport bike with a race-style chassis and 660cc Yamaha engine. This crossbred machine […]
This bike is a chopper not a bobber.
A bobber retains a recognizable look to its original form. Nothing here is bobbed. It’s chopped off and or replaced with new stuff. Certainly quality work . But it firs not appeal to me.
I like most of this build a lot, but I think a triangular seat with no tail piece would suit the look a lot better.
But as it is…well done for all the work you’ve put in to it….in three years time I’ll put mine up and see what feedback I get.