PROJECT HYBRID
Scoop with the latest on his KH250/500 project!
Wwelding’s certainly coming on.” Nice to know my project’s improving someone else’s practical skills then. As might be hoped the chain line is bang on and double checked using a rather rare and now expensive ARE alloy wheel with an old sprocket. In theory that should be the hardest part done but as this is a genuine special and I’m being a bit of diva here I want the bike to look subtly different. The KH250 tail piece is obviously the correct one but I really want the earliest squarer and wider unit as used on the 72/73 bikes. A brief mug-up clearly demonstrates it’s not going to be an easy job but when you set your heart on something etc. As I’m obviously now digging myself a fair sized hole here Ian cynically goes on to suggest I run an early style three-sided rear light as well. Apparently I might as well solve two problems rather than just the one! Fortunately I know of a man who should ell progress is being made and if it’s not necessarily by me then it’s by my mate Ian Bird, who has been cracking on at a right old pace. The 500cc H1 engine is now housed within the confines of the 250cc KH250 chassis and if you didn’t know better you’d have to say it actually looks right. And when Ian then dropped in the H1’s air-box and carburettor rubbers, two things were really obvious. Firstly, there’s really not that much difference in terms of inches or centimetres between the 250 and 500 motors and secondly, the KH’S frame has more than enough space to house everything the 500 needs to make run happily. Ian had fabricated then tack welded the new engine plates in place prior to passing the frame onto a top notch welder who subsequently commented: “Well that’s a really neat job Ian, your
be able to extricate me from this ever growing abyss of insanity. We need some decent brakes on this potentially rabid little missile but the question is what to use? Ian’s own hybrid uses a twin piston sliding caliper that came off a Kawasaki GPX750R. Thinking ahead for once I’d unearthed some four piston jobbies from my Yamaha FZR250 days, thinking they’d be super efficacious, but no. As Ian rather ably demonstrates, it’s simply not possible to use four piston calipers on a wire spoked wheel because the housing for the inner pair of pistons touches the spokes. He also gives me a look straight from Dad’s Army that says ‘you stupid boy!’ The front forks are now stripped and the inners dropped off at A M Philpot of Luton. They’ll give them a serious talking to, check they’re straight and apply substantially more hard chrome than Kawasaki ever did. Which just leaves the rear suspension and here it’s going to be hard to follow Ian’s example as his hybrid runs Koni shocks from way back when. There’s also a clearance issue with the chain guard so for the interim the bike will get built up with whatever comes to hand then we’ll take some careful measurements. There had been a sketchy idea to also run an earlier style tank which has a significantly more box-like profile but, for this facet of the build at least, common sense has prevailed. Looking at an early tank alongside the one actually intended for the KH’S frame it’s obvious there’s a lot of differences and it wouldn’t be a simple case of cut-and-shut. The earlier tank is significantly shorter than those used on either the S3s or the KH250/400 so
it’d have to be extended but then its rear-end wouldn’t match up with the KH’S seat nose. Knowing when I’m beaten I walk away from that particular daydream. At this juncture the newly welded chassis along with all of its peripheral components, the gently mouldering wheels, a collecting of tail pieces and all of the aluminium engine parts are gently poured into the back of my car. Ian waves a fond farewell to a raft of parts that have been cluttering up his workshop for weeks and I do a fair impression of the local scrap man ferrying the lot back to my workshop. The next few weeks see me mulling over what finish to use on the cycle parts and how best to sort out the wheels. One hundred point perfect originality is not what I’m after so I can’t see the point in getting the old rims re-plated. It’s not a cheap option anyway and if the bike is being built as a special why not treat it as such? A joyful Saturday morning sees me out with the bolt cutters liberating the hubs from the spokes and sometime later but the same weekend the old rusty bearings are finally evicted. With the alloy being so badly corroded the hubs are dropped off at T&L Engineering to be blasted (nuked?) clean so I can then fit new bearings. After some judicious pondering I’ve opted for stainless spokes and alloy rims but I’m avoiding the flanged type simply because they always hold crud and are harder to clean. To be honest I could build the wheels myself but with so much else going on in my workshop I’ve decided to flash the cash and ask Central Wheel Components to do the job. They come with a fine reputation and hold the alloy Morad rims I want in stock. I’ve finally decided to have the cycle parts ceramic coated which should give both a decent finish and also be harder wearing than either two pack or powder-coat. Alloy rims, stainless spokes, ceramic coatings? I told you I was having a diva moment!