Spirit’s RD400

Chris Bullick originally bought his RD400C in 1977 when he was a sixth former, and the same year that EMI signed the Sex Pistols, Star Wars was released, and Elvis left the building. The RD400 was a relatively short -lived model, produced for only three years from 1976-79, but was a bike that did wheelies off the throttle at a time when nothing else did, and handled better than its ‘characteristic’ Kawasaki and Suzuki counterparts. On a good day, a set-up RD could give a Triumph Bonneville or Norton Commando a run for their money.

1977′s model was supplied with US-spec tall handlebars, giant rubber footrests sedately positioned below the engine, and large self-cancelling indicators. It wasn’t long before Chris had removed the cow-horn bars, replaced the weighty chrome silencers, and repainted the bike with the classic yellow-black-white race livery of Kenny Roberts’ TZ750. …But that’s where the story stopped for 30 years.

Chris pursued a career across the globe, started a family and the RD slumbered behind a false wall in a garden shed. In 2012, having eventually got the kids to leave home, Chris decided that a restoration was in order, and a natural choice was Spirit of the Seventies in Chris’ native Kent where he used to thrash along the same A-roads as a lad.

Chris’ plan solidified that summer when he visited Tim and Kev at Spirit and a chance sighting of a Yamaha RD400/TZ350 hybrid behind the shed started “a conversation”, which turned into some ideas, then renderings, then a bone fide rebuild.

Spirit started by replacing the flimsy front end with an R6 setup, chosen for its performance and authentic-looking RWU forks, complemented by a Spirit headlight on LSL brackets, machined clip ons and Oury grips. Tim and Kev retained the original clocks and key-worn instrument panel as they are the familiar face of the bike: “Chris was looking at them all those years ago and it seemed appropriate to keep them. They could’ve been replaced but it wouldn’t have been right.”

Next, the “ridiculously heavy” original cast alloy wheels were replaced with refurbished later-model, lighter-weight RD400E rims wearing modern Bridgestone BT45s with a short carbon fibre Spirit mudguard.

The engine was vapour-blasted and powder-coated before receiving a re-bore, porting and jetting by Martin at Taymar Racing who shares the building with Spirit. Martin is a specialist in Yamaha 2-stroke restorations ever since racing and tuning LC350′s at nearby Brands Hatch way back when. New flat-slide Mikuni carbs (from a TZR250-2MA racer), foam air filters, and race-bred expansion pipes (that had been hanging in Martin’s workshop for 20 years but perfectly matched Spirit’s needs) helped release more power from the 40bhp motor.

Chris’s original aim was to lose 10kg to give the bike “a bit more zest” that could convincingly do a track day. Spirit’s and Taymar’s combined efforts created an extremely light 145kg rocket (20kg saved by ditching the original cast wheels and replacing the rear swingarm with a lightweight FZR400 alloy unit) that produces 50bhp at the rear wheel.

Since the lines of the bike were in Chris’ words “so timelessly right” he wanted to retain the original side panels and tank. A sophisticated grey-and-black Revolution paint job, subtly echoing the Roberts Yamaha race livery of the past, and a two-tone leather seat by Glen Moger did just that: keeping the original spirit but simultaneously updating it.

Well done Tim and Kev. See more from Spirit of the Seventies on their Bike Shed Pages or on their Website.

Posted by Hugo@TheBikeShed