Welsh Hot Rod: Yamaha XS650 Street Tracker by LC Cycleworks

A mechanical engineer builds one of the cleanest XS650 trackers we’ve seen…

The Yamaha XS650 arrived in 1969, a Japanese equivalent to the British twins featuring advancements like unit construction and a horizontally split crankcase.  The bike could run the quarter mile in a shade under 13.9 seconds, do 105 mph on a straight road, and endure more abuse than many of its contemporaries.  Meanwhile, the legendary Kenny Roberts would make the engine known on dirt tracks around the nation, competing in short track, half mile, and mile events on an XS650-powered tracker, bringing home multiple AMA championships and cementing the XS650’s reputation in the annals of motorcycling lore.

Enter Lynsey Christopher of LC Cycleworks, located in Wales, who’s been a mechanical engineer for 35 years. He would need all of that experience and expertise to salvage this ’76 Yamaha XS650, which the previous owner had modified with the help of a “professional” shop. Says Lynsey:

“My fears of the poor build standard were confirmed with the previous ‘professional’ work carried out, which revealed a piece of road sign as the speedo mounting plate, and very suspect welding modifications to the seat mounting sub-frame, along with plumbing pipe fittings holding the seat unit in place!”

With a pair of well-received builds already under his belt, Lynsey had a reputation to uphold. He opted for a full teardown and rebuild of the XS, working out of his single garage in suburban Wales:

“No bigger than your average shed, so proper shed build…”

While space can be a challenge, Lynsey has accrued quite a lot of tools and experience over the years:

“I do all my own machining, fabrication, welding, wheel building, wiring, small item powder-coating, painting, and small scale plating… If it needs doing and I can do it myself, I will!!”

In this case, the result is one quite possibly the cleanest, most well-executed Yamaha XS650 we’ve ever seen. Every last part of the bike was touched, and Lynsey is not a man to let details slide. When the bike’s oil consumption was slightly high on a test run, he stripped down the top end, honed the cylinders, replaced the rings, fitted new inlet valves, designed and built his own cam-chain tensioner, and rebuilt the motor with all new seals and gaskets.

He also modified the headstock to accept roller bearings, retrofitted a DT tank, rebuilt the wheels with new rims, fabricated a new subframe, did his own powder coating of small pieces, upgraded the front end with modern brakes, and much, much more.

Below, we get the full details on this stunning street tracker, straight from the man himself.

Yamaha XS650 Street Tracker: In the Builder’s Words

My 1976 Yamaha XS650.

I picked up the bike in January 2018. Plan was to recommission it, as it had not been on the road and the engine had not run since 2015. The bike had been modified to a “tracker” by the previous owner using the services of a “professional” bike shop. My intention was to get it running, then use it for the summer of 2018 as a toy for short blasts to the local biker café.

After cleaning out the carbs of green slime, I eventually got it running on one cylinder. I junked the original 70’s points driven ignition electrics in favour of a Boyer Bransden ignition system which helped the other cylinder into life. Closer inspection of the wiring revealed an absolute rat’s nest of insulating tape, domestic wiring terminal blocks and scotch lock connectors — basically a fire waiting to happen! I’d previously completed a full custom build of a basket case Yamaha TR1, which was well received at a few local shows and sold very quickly when it broke cover. I’d also previously completed a full restoration of a show-winning 1950’s AJS 350, so I had my reputation to uphold!!

That was it, a complete strip-down of the XS650, re-model and rebuild was in order. In keeping with the “tracker” look I didn’t want to go too radical and wanted to be sympathetic with the original Yamaha design, hence no radical forks or shocking paint jobs!

My fears of the poor build standard were confirmed with the previous “professional” work carried out, which revealed a piece of road sign as the speedo mounting plate, and very suspect welding modifications to the seat mounting sub-frame, along with plumbing pipe fittings holding the seat unit in place!

So the work began…

I have amassed a number of different tools over the years — 35 years as a Mechanical Engineer, you tend to accumulate one or two things!! I have a small garage in suburbia, no bigger than your average shed, so proper shed build…fitting it all in is a bit of a challenge. I do all my own machining, fabrication, welding, wheel building, wiring, small item powder-coating, painting, and small scale plating. I have a painter who does my tanks and larger tinware, which I use as a skills exchange for engineering related works on his builds. If it needs doing and I can do it myself, I will!!

So in brief:

Complete strip down to frame. Fabricated and welded in a custom made sub-frame for new seat unit. Handmade seat pad with Alcantara quilted custom cover. Main frame de-tabbed, and then powder coated. Headstock modified to take modern taper roller bearings. With custom-made hardware and top yoke modifications.

Engine compression tested, and was all good. It was sandblasted clean, modified engine side casings, blanking off the kickstarter hole, kickstarter removal, all engine ancillary components refurbished, new seals etc, powder coated and painted.

All small items powder coated by myself using my DIY kit. On test running the bike after completion, I noticed the oil consumption was a little high, so stripped down the top end and honed the cylinders, replaced the rings, fitted new inlet valves, custom-made my own design cam-chain tensioner, and rebuilt the motor along with new seals and gaskets.

Modified Delkavic 2-into-1 system to take single modified Dan-moto silencer, custom-made link pipe.

All the foot control levers, brackets, fasteners where reused, bright nickel-plated, again with my DIY homemade setup.

I fabricated and welded in bracketry for the alternative tank. New custom-designed engine mounts enabled a very badly damaged Yamaha DT400 off-road tank in lieu of the original XS650 unit. The tank itself was beaten back into shape by myself then handed over to my painter for him to apply my design.

Rebuilt both wheels with non-valance rims to match, new spokes seals and bearings, custom-made spindles and then fitted Heidenau K34 tyres for the retro look. Modified rear brake drum plate to incorporate some extra cooling details, more form than function! Custom-made torque arm and brake actuator rod.

Complete front brake upgrade from original Yamaha 70’s setup, using Ducati 916 brake disc, and Honda VFR brake caliper on custom made adapter bracket, coupled to KTM Duke Master cylinder. This was linked with braided custom hose and machined caliper mounting adapter.

Rear swing arm brace removed and complete new one designed, fabricated and welded in. Longer Hagon shocks fitted to raise rear ride height. Original chain adjusters redesigned and fabricated from 316 stainless, along with handmade castellated locking nuts.

Complete new loom made from scratch to incorporate Motogadget M-unit and custom battery box. T&T digital speedo along with custom-made micro push button switch gear mounted on “triumph” bend stainless 7/8” handlebars. Original charging system removed and replaced with combined reg/rec, LioN Battery.

Forks stripped, new stanchions and seals fitted, along with Hagon progressive springs, custom-made lock nuts. Custom-made dust seals to fit neatly with a Motolana CNC fork brace.

Original carbs replaced with set of Mikuni VM34 on custom-made alloy spigot adapters, and DNA filters. Homemade 2-1 throttle cable from bicycle gear cable. Custom-made leather grips and alloy machined throttle grips running a Domino quick-action design.

Foot control rubber pad and foot rests replaced with stainless off-road gripper design and custom-made mounting hardware. Lots of other minor details, including custom-made fasteners, brackets and widgets!

The colour scheme is a nod to the classic Yamaha livery, and is painted in pearlescent white, with the matching R1 red from its first generation superbike. Coupled with the gold powder coated rims gives it the retro look I was aiming for.

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