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A Triumph TT special built for a top sound designer

Triumph Bonneville TT special by Hello Engine
There’s something about a classic Triumph dirt bike: the appealing proportions, the chunky rubber, the swept-back bars and the plush seat. Put them all together, and you can almost hear a ‘click.’

Vintage off-roading Triumphs are variations on a formula—but like the songs of AC/DC, the formula works. And one of its greatest proponents is Hayden Roberts, an expat Brit living in California who runs the Hello Engine workshop.

Triumph Bonneville TT special by Hello Engine
Hayden’s latest build is this stunning Bonneville TT special. It was commissioned by Randy Torres, a sound effects editor who has just finished the movie Tenet.

Randy lives in Pioneertown, California, which is a living, breathing film set near San Bernardino worthy of a story in its own right. For off-road riders, Randy says it’s like “living at the beach if you’re a surfer.” (These photos were taken there, with a 30,000-acre wildfire raging in the distance.)

Triumph Bonneville TT special by Hello Engine
Randy has a collection of stock bikes, including a classic Yamaha TT500 and a Ducati Multistrada, but he’s also partial to the odd custom.

“I’ve been a big fan of Hayden’s builds for a long time,” he tells us, “so I hit him up to build a desert sled a couple of years back. Then I realized that I had enough dirt bikes in the garage—and wouldn’t want to dump a nice vintage Triumph on top of some boulders. I asked if we could do a ‘TT special’ instead.”

Triumph Bonneville TT special by Hello Engine
After kicking around a couple of ideas, and poring over archive images from the Ascot Park speedway track, Hayden had enough to work on. And the final product is the perfect bike for ripping around the California high desert.

As with most of his builds, Hayden created this one from scratch, using parts he either had lying around, hunted for, or found at swap meets. “I always save modified parts from bikes that are being restored—they’re perfect for projects like this.”

Triumph Bonneville TT special by Hello Engine
In this case, Hayden has used components from the ‘Desert Fox’ project that we featured just over year ago. “Randy saw that bike, and said, ‘Can we do the same kinda thing?’ So I started collecting used parts again—which sounds easy, but they’ve all got to have the same kind of wear. At least to me.”

Hayden has used a 1963 frame from an old Ascot TT (steeplechase) bike, picked up at an AHRMA swapmeet, and he’s preserved the patina whenever possible.

Triumph Bonneville TT special by Hello Engine
“The swing arm had been modified to accept disc brakes and it’s still got the tabs welded on for the riders’ number plates,” Hayden says. “I cleaned and repaired it, and clear-coated the old paint. I liked the way the spray from the front wheel has worn away the paint on the down tube.”

The engine is from a 1970 Bonneville motor, rebuilt with a mild race cam and balanced crank. It also has a CDI ignition, and doesn’t require a battery. “It’s just real simple,” says Hayden, “with hopefully very little to go wrong.”

Triumph Bonneville TT special by Hello Engine
The gas tank is a little older, coming from a 1967 Bonneville TT special. “I thought it was too nice to repaint, so I saved it. It went on ‘as is,’ warts and all.”

Hayden knows this will make no sense to some people: “Why build a bike from scratch, and not bother painting it? I don’t know… they took 50 years to make them look that neat.”

Triumph Bonneville TT special by Hello Engine
Most of the sheet metal is OEM Triumph, but bears signs of years of straightening, rebuilding and repairs. “Removing the left side cover leaves a big gap, so I modified that early filter and grafted on the big K&N filter,” says Hayden. “I stole the idea from a bike Bud Ekins built for Steve McQueen… it filled the gap and should keep the dust out.”

The bars are an original race set, and Hayden has installed a modified oil tank and a few period aftermarket accessories too. But under the ‘Lucas’ cover is a modern Hella 7-inch headlight. (“It’s nice to be able to see, and they don’t draw much power.”)

Triumph Bonneville TT special by Hello Engine
There’s a small twin leading shoe front hub, and the forks are slightly younger than most of the other parts—being from a later Daytona. The rear brake is from a CZ dirt bike: “It’s aluminum and much better than the stock tin one,” says Hayden. “I opened up the stock drum so it fits.”

The shocks are not replicas but rebuilt Girlings from a BSA, and about an inch longer than comparable Triumph shocks.

Triumph Bonneville TT special by Hello Engine
The seat looks old, but it’s actually one of the few modern parts on the Triumph. “I make these seats, they’re a copy of a Bates competition model,” says Hayden. “I use same injection molded foam as modern dirt bikes.”

For an authentic finishing touch, Hayden has applied decals supplied by his friend Gar Wood. “He’s in a great band called Hot Snakes. His dad was Ron Wood, of Rotax/Norton fame. He collected thousands of those stickers around the pits as a kid, and has shoeboxes full of them. I was lucky he gave me a few.”

Triumph Bonneville TT special by Hello Engine
Hayden is somewhat disparaging about his skills. “I’m a one trick pony I suppose—it’s mixed bags of Triumph parts every time. But I enjoy putting these together much more than a restoration.”

We enjoy seeing them too. And with a tinge of jealousy, we suspect that Randy Torres is going to absolutely love riding it.

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Triumph Bonneville TT special by Hello Engine