Building A 1965 Triumph T120 Bobber

Date 06.7.2016

Presented by
  • Motorcycle Trader


I blame my brother for my bike-building obsession, not that I’m complaining. It all started when Tom and a mutual friend raved about “the sickest bike” they’d ever seen; a Triumph ‘bobber’. – Pat Gheorghiu

This particular style of custom bike was unfamiliar to me and I was curious to see what the fuss was all about. The next day, inspired by Tom’s enthusiasm, I got him to take me to see the beast for myself.

Even before we pulled up at Antique Motorcycles, in Victoria, the awesome array of classic bikes spilling out of the warehouse doors was blinding. I was so excited I couldn’t even wait for Tom to finish parking before jumping out of the car to take in the gleaming metal and discover Aladdin’s cave.

I was like a kid in a candy store: overwhelmed, excited and without a clue of where to begin. This place really is the ultimate man cave.

After a quick browse I finally encountered the bike Tom had been raving about. It was an old, custom-built Triumph and it immediately caught my eye. Finally, I understood my brother’s excitement. That was it. My mind was set. “I’m going to build a Triumph bobber!” I returned to Antique Motorcycles soon after and negotiated the purchase of a 1965 Bonneville in fair condition. It was mine.


Before collecting the bike, I researched every detail about Triumphs, bobbers and customising. I had a clear plan and, from the moment it rolled into my garage, I didn’t hesitate and began the tear-down, but not before we kicked it over and took it for a few laps around the block.

When I started the project I didn’t expect it to take as long as it did with the final build taking a little more than two years. It morphed from a quick, easy project into an all-out, complete re-build with nothing overlooked and no expense spared. I wanted this to be a show bike for the street.

1965 Triumph T120 Bobber - Patrick Gheorghiu

With the bike littered across my garage floor I buried my head in more research for the best parts and methods for the build. I spent countless hours sourcing parts from the US, many of which are custom-made to suit the bike.

I had the wheels made as a special order and even the hardtail frame had to be made twice to accommodate the change in wheels I decided to fit.

Then there’s the front end and numerous other custom parts that were ordered and even fabricated to fit.

I somehow even managed to source a very rare and highly sort-after ARD-CDI magneto that’s no longer in production. This didn’t come without countless late nights researching and countless dead ends when everybody said the beautiful, tiny units were no longer available.

But, like a cop-show super sleuth, I tracked down a phone number of the company that used to build them. I stayed up late the next night to make yet another call to the US but, to my surprise, I sensed I phoned the private residence of a little old lady, not a cutting-edge engineering company.

I gingerly asked if Alan was there. “Just a sec,” replied the shaky voice before shouting “Al!” By then it occurred to me that I had in fact called somebody’s house, but I was still hoping for clues that might lead me closer to the magnetos.\

1965 Triumph T120 Bobber - Patrick Gheorghiu

Would you believe I actually rang the man who made them at his home? Alan confirmed he was indeed the one who used to fabricate these magnetos.

“Is there any chance you know where I could get one?” I asked with resignation.

“Oh, I make a few now and then, but it does take a bit longer these days, you know,” he said. I ordered one immediately without care of price or how long it would take Alan. Five months later it finally arrived to my door step. It was worth it.


A year into the project, I’d unfortunately made little visual progress but I’d made plenty of headway sourcing parts. I had just about everything I needed to begin the assembly process.

As several months went by, the project’s momentum almost halted as my enthusiasm ran low. That didn’t stop me from turning my attention to another quick and simple bike build to get up and riding in the meantime. The intense bobber project was made way for a 1988 Honda GB500 TT café racer, but that’s another story.

Further distractions came along with two other bike builds, but it wasn’t until Tom’s SR500 (MT #276) and my friend Jolan’s Yamaha XS650 café racers rolled out of my garage that my enthusiasm for the Triumph project was reignited.

Progress kicked up a notch and the bike started to take shape. The engine was fully rebuilt with a billet alloy big-bore kit including polished covers and a dry clutch with an open side cover to expose the spinning clutch plate – Ducati style.

1965 Triumph T120 Bobber - Patrick Gheorghiu 1965 Triumph T120 Bobber - Patrick Gheorghiu

Everything was polished and ready to go into the frame, which was cleaned and stripped of all unnecessary brackets then powdercoated.

The assembly process was relatively smooth thanks to the countless hours of research, pre-assembly, trials and fabrication.

In hindsight, the build seems easy and straightforward but, when I think about each individual part of the bike, everything had its own dramas and hurdles to overcome.

Some of the parts I thought would’ve been easy ended up being bloody hard, yet others I thought would get the better of me were thankfully a breeze. Buying parts that don’t fit, suit or even work is all part of a build first time around and doing it all again would be much easier, which is a possibility given I have enough left-over spares to complete another bike.


The bike’s braking system comprises discs front and back including a rear sprocket brake for a clean, simple finish. I used two cable-operated master cylinders to actuate the calipers and the billet master cylinders are held in place by a custom-made billet alloy bracket I designed in CAD.

The custom-made hardtail frame needed extra attention so I welded mounting brackets for the rear guard, disc rotor and seat springs. I cut the rear guard to allow the chain to pass without touching and welded mounting tabs to line up with the frame brackets. The footpegs needed to be cut and re-welded in a new position to pass the exhaust pipes, too.

The bike has been entirely rewired using vintage cloth-covered and metal-shielded wire with most of it done by the Jolan – perhaps returning the favour for building his XS650.

I also tooled the leather seat using a kit I bought online and etched a koi fish and ‘65’ graphic.

1965 Triumph T120 Bobber - Patrick Gheorghiu

The choice of paint colour didn’t come easy. I spent a lot of time looking online at other bobbers and even mocking up colour options in Photoshop but, in the end, it was a late-night repeat of Gone in 60 Seconds that inspired the final colour outcome. Seeing ‘Eleanor’, the ’67 Shelby Mustang GT500 with its iconic gunmetal grey and black GT stripes was all the inspiration I needed.

I called the painter I used for my Honda GB500 build and set the wheels in motion, but the bobber’s paintwork wasn’t without its share of dramas. After a miscommunication about the size of the GT stripes he had to redo the entire paint job. This was going to be a show bike after all and I wanted perfection.

With assembly complete I realised, “Finally, it’s done! All that work, effort and time I spent was all worth it.” Seeing the number of people look and admire the bike and want to talk about it makes it all the more rewarding.

1965 Triumph T120 Bobber - Patrick Gheorghiu

SPEX | 1965 Triumph T120 Bonneville ‘Bobber’


750cc big-bore kit including Billet alloy cylinder barrel by Map Cycles

ARD-CDI Magneto

Belt-driven primary with dry-clutch conversion

Billet alloy rocker box caps

Billet alloy rocker box oil feed by SRM Engineering

Stainless oil-pressure release valve

Oil-pressure gauge custom mount

Wet blasted

Polished covers

Twin 930 Amal carbs

Velocity stacks

Alloy carb spacers

Billet alloy engine mounts

1.75-inch drag-style exhaust, heat wrapped


Elswick Cycles hardtail bolt-on frame, powdercoated gloss black

Mean Street inverted alloy forks

Exile Cycles front disc brake

Exile Cycles rear sprocket brake

Kustom Tech brake master cylinders

Custom-made brake master cylinder bracket

Venhill braided stainless cables and lines

1965 Triumph T120 Bobber - Patrick Gheorghiu


21-inch front wheel, brushed alloy with Avon Speedmaster tyre

19-inch rear wheel, brushed alloy, Firestone Deluxe Champion tyre

1965 Triumph T120 Bobber - Patrick Gheorghiu


Elswick Cycles oil tank

1.0-inch inverted handlebars

Internal throttle

Posh Gum grips

48mm speedo, custom mount

Solo seat, custom tooled leather

Custom paint with Ryan Ford pin-stripping


Author & bobber-builder, Patrick Gheorgiu