1957 Triumph Thunderbird

Triumph Thunderbird motorcycle
Clay Rathburn of Atom Bomb specializes in low-key customs, the kind that have a charm that grows on you. This is his latest bike, a 1957 Triumph Thunderbird built for Corey Theuerkauf. ‘Corey’s dad Tim started gathering parts to build himself a Triumph twenty years ago,’ says Clay. ‘But he recently passed away unexpectedly. His family decided to finish the project, and asked me to get it done.’ It was a pretty emotional thing for everyone involved, especially since no one knew exactly what Tim had in mind for the bike. Tim’s collection of parts was large and varied, and didn’t provide much in the way of direction. So Clay decided to go for a clean and simple build: ‘a mix of traditional chopper/bobber with a bit of Atom Bomb thrown in.’

Triumph Thunderbird motorcycle
The engine is fully rebuilt to stock Thunderbird specs, with low compression pistons. The original magneto was long gone, so Clay used a Joe Hunt. The frame was more troublesome, though: Clay discovered that an aftermarket hardtail for a unit Triumph had been welded on. ‘It didn’t fit, it was on crooked, and the front section was more or less ruined.’ So Clay built a complete custom frame onto the factory neck. The tank is an original Wassell that Tim had, and the rear fender is fashioned from a 1936 Ford spare tire ring.

Triumph Thunderbird motorcycle
Clay originally planned to shorten and use a very long springer front end that Tim had found, but it was bent up in the trees. So he located a set of oil-in-frame Triumph forks, and shaved and polished them. The bars, exhaust and miscellaneous parts were all made in house. Corey Theuerkauf now has an elegant, classy ride—and a fitting tribute to remember his father by.

Images by David Bradley.

Triumph Thunderbird motorcycle
Triumph Thunderbird motorcycle