Licks Cycles: Suzuki GT380 Flat Tracker

Two-Stroke Triple Tracker from Moore’s Competitors Cycles…

Throughout the Seventies, the Suzuki GT sequence of three-cylinder two-stroke avenue bikes by no means earned fairly the identical widow-making status because the infamously quick and deadly Kawasaki triples…primarily as a result of the Suzukis have been designed as extra well-rounded machines.

“Again in 1972 Suzuki had a brand new thought: Take the newest in superbike expertise. Scale it down right here, beef it up there, and also you’d have a nice mixture of touring, sport, and commuting, all for a horny value.” –Cycle World, 1976

The GT380 was designed for the hotly contested 300-400cc market. It featured the Ram Air system Suzuki had developed for its street racers, a six-speed transmission, and a entrance disc brake on all however the earliest fashions. The 371cc engine was rated at 38 horsepower and 28 lb-ft of torque, with porting, timing, and compression geared towards longevity and clean energy supply relatively than peak horsepower.

Enter our good friend Jesse Moore of Moore’s Competitors Cycles, a self-proclaimed flat monitor addict who grew up racing motocross and hanging out within the workshop of his father, an engine-builder who works on 60s Grand Prix automobiles. Again in 2019, Jesse discovered his approach to flat monitor via DirtQuake and hasn’t regarded again.

When it got here time to construct a flat tracker for his dad to race within the UK’s DTRA (Dust Observe Riders Affiliation) rounds, they picked up a GT380 donor…not realizing fairly how trashed it was:

“When the body got here again from the blasters, it was clear simply how nasty it was…the welding had been achieved by the again of a pigeon, and the entire bike simply regarded mistaken after we assembled it.”

Whereas many builders may need deserted the mission at that time, the Moores doubled down. They determined to place their fabrication prowess to good use, constructing their very own body out of T45 tubing. Says Jesse:

“It might be primarily based off of an excellent good friend’s ‘Shell Thuet’ flat monitor body, which I measured and drew, after which modified barely to accommodate the large Suzuki engine.”

The geometry, wheelbase, and heart of gravity at the moment are significantly better suited to the monitor, whereas the engine has been rebuilt with X7 pistons, labyrinth seals, and a Zeeltronic programmable ignition. The oil pump was ditched to run premix, the generator eradicated in favor of a total-loss system, and the Moore boys constructed the exhaust out of 100 separate sections.

Chris Pugh (@shed_days) dealt with the paint, so this smoker seems pretty much as good because it goes, and the Moores have been very proud of the bike each on and off the monitor:

“It’s quick, it handles superbly, and it’s actually cool to see how individuals react to one thing we actually simply made for a little bit of amusing. We’re producing our frames, pipes, and different parts now to promote, and I wish to suppose that this can be a little bit of a showcase of what we will do.”

Beneath, Jesse Moore (@jessemoore72) provides us the complete story on this triple-cylinder two-stroke tracker.

Suzuki GT380 Tracker: Within the Builder’s Phrases…

We wished to construct a three-cylinder two-stroke flat tracker in order that we had one thing completely different that will sound good and switch heads, and in addition give Dad one thing to journey on the DTRA rounds right here within the UK. We set about looking for a donor bike, however Kawasaki triples have all shot up in worth in the previous couple of years, and discovering one was going to be unattainable with our preliminary funds, so Dad discovered a Suzuki GT380 — and a extremely nasty one at that!

We laced up a set of 19 x 2.5″ rims onto the Suzuki hubs, mounted some Maxxis flat monitor tyres, discovered an honest set of forks and yokes, and despatched the body off for blasting to see what we have been working with, beginning to stability all of it collectively. When the body got here again from the blasters, it was clear simply how nasty it was…the welding had been achieved by the again of a pigeon, and the entire bike simply regarded mistaken after we assembled it. It simply regarded like a 70s avenue bike with large fats tyres on it.

After eager about it for a bit, we determined to make a body. It might be primarily based off of an excellent good friend’s “Shell Thuet” flat monitor body, which I measured and drew, after which modified barely to accommodate the large Suzuki engine.

By constructing our personal body, we managed to unravel a number of our preliminary issues, for instance:

The headstock is now set on the appropriate angle to get it to show in, nevertheless it’s additionally 4 inches larger than it was on the inventory body, successfully dropping the engine 4 inches and naturally the centre of gravity.

The wheelbase is brief, permitting much better traction out of the bends, and extra agility into the turns.

The seat peak is low, retaining you nearer to the bottom and making the bike really feel actually planted.

The body is basically mild; it’s fabricated from thin-wall t45 tubing, and with the swingarm it weighs simply 8 kilograms, some 15 kilos lower than the inventory body.

We additionally tipped the engine ahead, once more to get the centre of gravity decrease, but additionally to raise the sprocket and permit us to lift the swingarm pivot level, placing some angle into the swingarm and once more enhancing hook up. This bike actually drives out of the nook, not what you’d count on from a three-cylinder two-stroke!

The engine is fairly normal actually. We used Suzuki X7 pistons to offer just a little extra inlet period, moved the crank bearings, and used labyrinth seals to seal between the crankcase sections, and redrilled the oil methods to permit us to throw the oil pump meeting within the bin and run premix.

It additionally makes use of a totally mappable Zeeltronic ignition system. Utilizing the ignition system meant we might run it whole loss, so didn’t want to make use of the generator within the engine, in order that was one other heavy lump we received to throw away. We went forward and minimize the aspect cowl down too, because it not wanted to be so extensive, just a little flat aluminium cowl would do, and that will assist slender the already very extensive engine — it saved a bit extra weight too

The identical remedy was given to the entire engine; something that we didn’t want was minimize down or eliminated. Aside from that, it’s normal. We’ve received just a few plans to enhance it: I feel we’ll elevate the cylinder on the base gasket and proper the squish by decking the highest of the cylinder, that may enhance the port timing and get it to go just a little higher, though it sings at 11,000 rpm already, so perhaps it’ll do for now.

The pipes have been our subsequent problem; there are over 100 items in them they usually have been designed, rolled, routed, and welded by us to go well with the bike and what we wished from it.

They’ve actually woken up the bike they usually actually sound nice, and let’s face it, that’s the principle factor with a three-cylinder smoker.

Our mate Chris Pugh (@shed_days) painted it for us in traditional Suzuki colors. We gave him free rein to do it how he thought it ought to be, and I feel you’ll agree, he did a very nice job.

The bike has gone down very well in all places we’ve taken it. It’s quick, it handles superbly, and it’s actually cool to see how individuals react to one thing we actually simply made for a little bit of amusing.

We’re producing our frames, pipes, and different parts now to promote, and I wish to suppose that this can be a little bit of a showcase of what we will do. We will design and construct something you want inside purpose, and I feel this bike exhibits that.