Necessity, they say, is the mother of invention. And here’s a case that proves invention is the mother of all hot rods.
Dave Greenwood, not unreasonably, imagined he could build a Yamaha SDR200 from scrounged parts. He got hold of a frame, seat, tank and airbox on eBay, then set about finding the rest. “I just couldn’t turn much stuff up at all, it just wasn’t out there,” he says. “But I did have a YPVS engine.”
Dave’s got form when it comes to skinny chassis and big (or at least bigger) engines. His name might be familiar to anyone who saw his TZR125-engined Fizzie (PS issue 66, April 2016). His handiwork might look equally familiar too. “Things are built to be used and abused,” he says. “Once something’s together and it works, I don’t see the point of tearing it all down again to make it look brand new.” His TZR Fizzie was a product of precisely that philosophy – and so is his latest creation.
“There was a French guy who put a Yamaha YZ250 motocross engine in an SDR,” says Dave. “And he said he thought about putting a 350 twin in it but it wouldn’t fit, and I just thought ‘Yeah, it will’. So, I cut all the SDR engine mounts out and offered-up the YPVS motor as far back as it would go in the frame. And it was tight. Then I made a cradle for it, I think it was an FZR400 piece chopped and welded to suit.
“Now that it’s in, the clearance between the downpipes and the front wheel is really tight.” Tight to the extent that Mick Abbey, who hand-made the spannies, had to tailor them twice to get both the right sections and bends – and adequate clearance. “I can’t speak highly enough of Mick,” says Dave.
When things look impossible, they might be difficult– but not impossible. There’s nearly always a way – if you go at something hard enough and long enough, and from different perspectives.
Chat about things with mates, in fact with anyone. Someone some where will always know something you don’t, or someone who can help.
Stick with it. Never give up. Walk away for a bit, sure. I put
a cover over this for two years, dropped it completely, until I had a chat to Mick Abbey and then I was straight back on it.
“He built the engine in a ‘fast road’ tune and as it stands it’s doing 70bhp at the back wheel on the dyno. We’ve still got to fine tune it, but as a baseline you can imagine what that feels like in an SDR.” Well, yes.
The stock SDR is a 30bhp bike crying out for 40 or 50 ponies. It weighs 113kg (250lbs). Dave’s not had his machine on the scales, but estimates it can’t weigh more than an extra 20 or 30kg over the stocker.
So, if we settle on a figure of 25 kilos heavier, that gives us a real 70bhp propelling 138kg. Elementary mathematics (as a rough measure of its general liveliness) tells us that’s a power to weight ratio of 0.50bhp/kg. A MotoGP bike is around 1.50bhp/kg, a Kawasaki ZX-10R 1bhp/kg. It’s not in the upper realms of madness, but it’s no slouch. And in the great scheme of things, it should always be more about how fast something feels, than how fast it actually is.
YZF125R front end seems happy in its work.
YZF125R front end seems happy in its work.
“I haven’t been on the road with it yet,” says Dave. “I’ve been on some ‘private’ roads and it’s explosive. It’s not registered yet, but I’ll be doing some trackdays on it, and it should be a bit of fun. It handles nicely and it’s probably good for 130mph, but I wouldn’t want to be on it at that speed. The acceleration is epic though.”
Dave began this job five years ago. When he realized SDR parts were so thin on the ground, he turned to the most readily available equivalents. “A lot of it’s YZF125R,” says Dave. “The wheels and forks, front mudguard, rear hugger… the forks went in fine, the wheels were OK with a few spacers, I made a stainless steel chainguard, then I had a rolling chassis.”
That’s when his mix and match, fits where it touches attitude paid massive dividends. “I knew it needed a fairing and I was looking at the sort of universal stuff on eBay, and it all looked rubbish. The I found a Ducati 1098 item and it looked really small and sexy, so I bought it and it looked so right I went and got the two side panels, cut them down a bit and they looked absolutely made for it. I was very pleased with that.” You’ll notice the fairing lowers carry the number 49. “Yeah, the numbers were on there and I didn’t see any reason to start repainting things so that’s where they’ll stay,” says Dave. “They look alright.”
They do look alright. The whole thing looks alright, much to do with the sinewy SDR looking alright to begin with. The skeletal trellis is key in the way that unless the angles are all wrong and the welding gash, a steel spaceframe is usually a thing of beauty. It makes a bike look light and agile. Dave has casually but effectively enhanced this look.
“The front brake’s still a YZF, the seat’s SDR, Koso clock, all small, neat stuff,” he says. “I couldn’t find a rear subframe anywhere, so I made one, and a triangular airbox and battery box to keep the Zeeltronic ignition in, I also fitted an oil tank in there too, it might even be an old Fizzie one.” This tight packaging keeps the slim looks and ensures there are no rats’ nests of plumbing and wiring to spoil the aesthetic.
“I did have cooling issues and after a bit of thought a mate suggested a Honda CBR600RR rad because it’s curved and was about the only thing that would squeeze in that tight spot between the front wheel and exhausts,” Dave says.
You’d never call this machine immacualte that’s not Dave’s style. It’s built to be mechanically pitch-perfect and cosmetically passable.
You'd never call this machine immacualte that's not Dave's style. It's built to be mechanically pitch-perfect and cosmetically passable.
Dave also rides a ZX-12R and is looking at finding, wait for it, a BMW R1200GS. The Kawasaki’s actually quite cramped for a big bike, and I’m not going to ride the special on the road much, it’s really a track bike. Something that comes on the power at 6000rpm and doesn’t fall off until around 10,500 is hard work on the road. But when you wheel it around it feels like a moped, you know you’re the boss. And it doesn’t wheelie that violently either. Even with a short wheelbase (1335mm) there’s so much of your weight over the front it actually behaves itself.
It’s a blindingly neat little bike, with a big sting and Dave knows he’s formulated something nice and nuts without it being too overblown. “There’s always a compromise with any special – but this one seems to have absolutely nailed it. A lot of its appeal is the look, but that Mick Abbey YPVS engine is killer. I don’t know how I’m going to top this, and it’s probably my last special… but you should never say never.” Never.
SPECIFICATION YAMAHA SDR/YPVS
350cc YPVS, Mick Abbey ‘fast road’ tune: raised and widened exhaust ports, re-angled and reshaped transfers, Abbey race pipes, Zeeltronic ignition
ck Abbey has to cut and shut, those race pipes (a lot) to fit.Chassis
Yamaha SDR200 frame, Yamaha YZF125R forks, brakes, front and rear wheels, Ducati 1098 fairing, Koso clock, YamahaFS1-Eoil tank, home-made rear subframe