PETER HARRIS’ KAT IS A CLEANLY PUT TOGETHER LABOUR OF RESPECT FOR HIS LATE MATE DAVE. IT ALSO HOUSES ONE OF THE BEST-FETTLED BIG-INCH GSX ENGINES AROUND
Say someone gave you a Katana in bits… you’d be pretty chuffed, right? That’s what happened to Peter Harris. But the bike was a gift from his mate Dave ‘Swingarm’ Roberts, and Dave died in February 2016, leaving the Kat to Peter. So it was received gratefully, humbly, and with mixed emotions.
“He was called Swingarm because he always liked a stretched bike,” says Peter. “And when I say stretched I mean 8-inches over – or more. He was always called Swingarm, everyone knew him as Dave Swingarm. I’d known him for 15 years, and when he passed away, his partner Jane said, ‘Dave’s left you a bike’. He left me the Kat, Garry Bond got his Harris Magnum, and Leigh Kerridge inherited his Bandit.”
The Katana was in large lumps. “It came in boxes,” says Peter. “He’d collected all the bits and it was case of putting it all together exactly as Dave would have done. I knew he liked a black bike, and so the Katana is about as black as it can be. The Magnum and the Kat were the two he never got to build and the Magnum’s now finished too.” The engine went to Roger Upperton for what Peter describes as a, “sump plug-up rebuild.” Taken out to 1170cc, the GSX11 plant runs forged MTC pistons and Web camshafts, the head’s been flowed and it runs Mikuni RS38 flatslides on open velocity stacks, fed by a twin-outlet high-flow Pingel fuel tap. The rear oil take-off and catch tank was engineered by Stuart Crane at Warpspeed Racing in Norfolk and the frame-mounted, highly necessary oil cooler is a Hel item. On Ken Cooper’s dyno (in Feltham, Middlesex) Peter says it made peak power of 138bhp, with 84lb.ft at 6500rpm.
That’s big, useable power and torque. “It goes like a bullet and sounds just mental,” says Peter. “It’ll dawdle along in top gear down to 15mph, but it’s a crazy engine too. I’ve only done about 700 miles since I finished it – but I’ve got to say they’ve been fast miles – it’s an absolute demon.” And that demonic power was never going to be tamed by a stock Kat chassis. Always the way with significant modifications, you up performance and the whole balance of a bike changes; what used to be a decent enough frame can no longer take the strain, brakes become wholly inadequate, and a huge raft of upgrades is needed to make the thing gel again.
The frame went to Saxon Engineering in Stoke-on-Trent where Stuart Petts not only checked the factory welds and braced it where needed, but also shifted the swingarm pivot point forwards and upwards to accommodate a TL1000S swingarm with, you’ve guessed it, 6-inches of drag spec chain adjustment for that full Dave Swingarm stretch effect. The standard spindle is a mere 18mm diameter – this one’s 24mm. No chances have been taken in ensuring this Katana has a structural integrity bordering on overkill. However, if you want to use all that power, want to use it as intended, then there has to be as much work on the chassis as the engine. It sits long, low and lean, and aside from the all stock Katana cosmetics, there is isn’t a part of this that hasn’t been modified and improved.
A GSX-R1000K5 front end is suspended in stepped ally billet yokes, stock monoblock calipers work 320mm petal discs all modulated by a Brembo mastercylinder. The brake rotors spin on a three-spoke Dymag up front, same at the rear, with just the one wavy disc. A single Koso clock takes care of instrumentation, and by that we mean tachometer only with integral digital speedo. The cockpit is a model of minimalism, and what little there is, is held in its spot with stainless steel fasteners.
“It’s got to be stainless steel everywhere for me,” says Peter. That extends to the all-stainless MotoGP Werks pipe brought in from their factory in Anaheim, California, likewise the almost compulsory Dyna ignition for big Suzukis, again from the US, this time Las Vegas, Nevada.
The Harris rearsets are from way closer to home though. And much of the refurb work went to a web of local specialists and mates. The seat recover was by Lucky Seven in Newport Pagnell, Viz made the custom wiring loom and with everything all set for a long and a happy life, the reg/rec decided to throw in the towel. “It’s a common problem with all big Suzukis,” says Peter. “It goes AWOL and then fries the battery.” Peter had the whole electrical system apart before the photo shoot making sure it was back together and fully functioning. Which it was.
Peter knew that the black finish Dave Swingarm would have wanted could not just be any old black. “There are so many types of black,” he says. “And so many finishes too.” He knew what he wanted and where though. The engine’s in a flat black, the body parts satin black, and the frame a textured, crinkle black. “It looks like it’s been dipped in glue, rolled in sand – and then painted.” The work was done by Paul at Roadrash Paintwork in Leighton Buzzard. “Everywhere it goes people stand back and go ‘Wow’,” says Peter. There’s a reason for that. It’s subtle but in your face at the same time and it’s been very neatly engineered.
1. Great symmetry with the single central dial and matching mastercylinder reservoirs. Top-mounted clip-ons make riding position more forgiving too
2. Plumbing and routing are what can make or break a special, and Peter’s attention to detail here makes it what it is
3. Those 38mm Mikuni flatslides on open bellmouths chuck a lot of mixture into the Twin Swirl chambers. Induction noise must be glorious too
4. MotoGP Werks pipe is a thing of beauty and there’s no doubt it works well too. Those dyno figures didn’t happen by accident
SPECIFICATION SUZUKI GSX KATANA
ENGINE: SUZUKI GSX 1170CC, DOHC, 16V INLINE-FOUR. MTC FORGED PISTONS, WEB (USA) CAMS, 38MM MIKUNI RS FLATSLIDES ON OPEN BELLMOUTHS, MOTOGP WERKS STAINLESS STEEL FOUR-INTO-ONE, DYNATEK IGNITION
CHASSIS: SUZUKI KATANA FRAME BRACED AND STRENGTHENED, SUZUKI TL1000S SWINGARM, ÖHLINS REAR SHOCKS, DYMAG THREE-SPOKE WHEELS, SUZUKI GSX-R1000K5 FRONT END, 320MM PETAL DISCS, BREMBO MASTERCYLINDER, ONE-OFF STEPPED ALLY YOKES, KOSO TACHO, HARRIS REARSETS
“Things like the braided stainless steel hoses and fittings came from torques.co.uk. If you know what you want and can spec it up properly they work out at about half the price of the usual suppliers, and their stuff is every bit as good,” Peter says. “There’s no way I’d risk ruining a bike by fitting anything that wasn’t top notch.”
The build took seven months and on completion Peter, Garry and Leigh rode all three of Dave Swingarm’s bikes up to Duxford, Cambs to visit a mate of Peter’s who works at The Aircraft Restoration Company. “We’re all from within an hour of each other so we all rode up together. And when they found out the story of the bikes they only went and pulled a Spitfire out of a hangar for us so we could take a photo of all three bikes with it and give it to Jane as a memento. They didn’t have to do that.” Peter had to sell his Slingshot and his GSX1100ET to finance this build and of course this bike will never be for sale. “I’m going to keep it more or less exactly as it is now,” says Peter. “And we’ve got plans to go to the Isle Of Man later this year and maybe get to Spa too.”
All of the late Dave Swingarm’s bikes have the same plaque attached to them, a heartfelt tribute to a friend who plainly thought a great deal of his mates too – enough to entrust them with three things very dear to him. And those mates have kept that trust invested in them. Typically Peter is still thinking about engine improvements. “I may take the engine to 1371cc at some time in the future,” he says.
“Dave lived life to the full, but it took its toll,” says Peter. The trio presented the three finished bikes to Jane last April. But there’s a sad twist in this too. “Jane’s very ill now too unfortunately, and it would mean a lot to her to see this bike get the recognition it deserves for Dave,” says Peter. It’s a fine machine, clearly with some fine people behind its story too.