The bike’s a 1991 Honda CR500 that already had the hardest piece of work completed when it came into my possession - the fitting of the seventeen-inch wheels. Once that’s done, there’s very little work required to turn a full-on motocross bike into a road going missile that’s capable of annihilating absolutely everything else on the road. It may only be a single two-stroke. It may only produce around sixty five brake horse power, but that power gets to the rear wheel with unbelievable efficiency thanks to the race-spec crank that weighs absolutely nothing. When the power kicks in, it kicks in hard, fast and unrelentingly. A true two-wheeled roller coaster ride that’s capable of landing its rider on his arse before the pilot even knows something below him has gone wrong. So, what needs to be done to a CR to turn it into a ‘motard? First, and most importantly, is the removal of the original wheels for seventeen inch ones. There are two ways you can do this. If you want an ultra-trick looking machine than you can get the original hubs laced up to new rims, or even complete new wheels built specifically for your machine by someone like Talon Engineering who are based in Yeovil, Somerset (Tel: 01935 471508, Fax: 01935 431825, www.talon-eng.co.uk) or the Central Wheel Company who you’ll find operating out of Birmingham (Tel: 01675 462264, Fax: 01675 466412, www.central-wheel.co.uk). This isn’t the cheapest way of doing it, though, as a complete set of new wheels will cost you around the five hundred quid plus mark. Having said that, they do bolt straight in which is always an advantage. The other choice is to get a pair of RGV or race-rep 400 wheels from a breakers and get some spacers made up by your local machining shop. When it comes to choosing which wheels to go for, your main priority is to get a rear that’s the correct size for a 160 tyre as anything smaller will not allow you to fit super sticky race compound tyres which you’ll desperately need when the irresistible urge to go ‘motard racing kicks in - and it will. But you don’t want a five and a half inched rim hoop as you’ll have great difficulty getting anything larger than a 160 profile tyre in a standard motocross swingarm. Plus a larger tyre will only slow down the bike’s cornering ability which you really don’t want to do. Well, it’d be completely pointless having a slow steering ‘motard because that’s the exact opposite of why you’re building the damn thing in the first place. Once the wheels are in place your next problem will be getting the calipers mounted correctly for the new brake discs. At the rear the original caliper will be more than up to its new job but you may find you’ll have to live with the fact only 99% of the brake pad is in contact with the disc due to the way the caliper is mounted directly to the swing arm. The front end, however, is a different matter. For a start you’ll need to bin the original caliper. It will stop the bike, even from high speeds, but because of its size and the greatly increased work load it will have to deal with, you’ll find the hydraulic fluid will boil very quickly leaving you with a brake lever that comes all the way back to the bars with little, if any, forward retardation in evidence. It’s a much better idea to find a four-pot caliper from a modern bike instead - but don’t go for anything too trick such as a Billet six-potter as that will simply be far too efficient for a bike that only weighs one hundred kilograms - you would pull a superb stoppie, but that would be rapidly followed by the rear half of the bike overtaking your head before slamming your face into the asphalt. Not what you want. Obviously, a front caliper bracket will need to be fabricated, but as it shouldn’t be the most difficult piece of alloy ever machined, the cost should be fairly small. Don’t ignore the front brake master cylinder either. Although the standard will probably do the job, it’s worth remembering that you may have to replace it with a road going one that contains a front brake light switch (for the MoT) and a larger piston bore to handle the new four-pot caliper. Next up is the cooling system. As the CR is a race bike, the water cooling system doesn’t come with any sort of thermostat fitted. This isn’t a problem when the bike’s in its natural environment - off-road, covered in mud with an engine that’s under full load 99.9% of the time - but for ‘motard racing and general road use the cooling system works too damn well leaving you with a bike that’s an absolute nightmare to get warm, especially in cold weather. You could blank off the twin radiators using something like gaffa tape, but then you have the problem of the bike possibly overheating - especially if the weather suddenly gets warmer. Plus, the cooling system doesn’t have a fan to assist with cooling, either, so that’s out. Removing one of the radiators is also out for the exact same overheating problem. This just leaves fitting a thermostat, but which one and from where? A little searching on the ‘net later and the answer is clear - Yamaha snowmobiles apparently come with free-standing thermostats that can be easily spliced into the cooling system without any need for any machining. They also come in different temperature ranges which makes them the perfect solution. All we’ve got to do now is find someone in the UK that deals with snowmobiles. Bugger… One other thing the engine needs is more low to mid range power. Four strokes like the Husqvarna 610 and KTM don’t really have this problem, but the two-strokes definitely do. The simplest solution is the gorgeous FMF exhaust that comes in 18-gauge chromed steel, which is allegedly indestructible (well, almost), boosts the low to mid range quite considerably, sounds superb and doesn’t cost the earth - especially compared to four-stroke road exhausts. Rush Racing (Tel: 01404 549696, www.rushracing.co.uk) are the new official importers of these Yank works of art, but if you’ve got a four-stroke then they do systems for them, too. Once you’ve got the wheels fitted and the cooling sorted there’s very little left apart from the machine’s aesthetics. The polishing can be handled by any local firm - or yourself if you feel like being covered in polishing soap for hours on end. The yokes and swingarm will look absolutely stunning once they’ve been visited by the polisher’s mop. As for the plastics, motocross bike’s bodywork is dirt cheap when compared to road going plastics. Even if you choose to use the most expensive aftermarket bodywork by someone like Acerbis, it still won’t cost you an arm and a leg. This particular CR will end up being covered in Acerbis bodywork that’ll be supplied by the wonderful Bert Harkins Racing (Tel: 01582 472374, Fax: 01582 472379, www.bertharkinsracing.co.uk). Of course, if you want the bike to be road legal then lights and a horn are required. As CRs, or any off-road race machine for that matter, don’t come with any type of lighting system fitted, you’ll need to do that yourself. Somewhere like Electrex (Tel: 01491 682369) can supply a simple bolt-on generator that provides you with a single live feed that you can then turn into a basic wiring loom. Oh, stop whining, it’s really very easy. All you do is get a little ‘bar switch, that has a horn button and light switches, from Big Four Engineering (Tel: 01663 734322, www.bikehouse.demon.co.uk/big4), take the live feed from the new coil and follow the instructions that will come with the switch. If you can fit a blade/bullet connector and can solder so that it lasts more than five minutes, then you can build a ‘motard wiring loom. As for the headlight and stop/tail light units, again you want Bert Harkins Racing who will happily provide you with a beautiful Acerbis unit - or, more precisely, tell you who your local supplier is where you can get your bits from. Extra Special Thanks To: Michelin Tyres Tel: 01782 401853 (Pilot slick tyres) Bert Harkins Racing - Tel: 01582 472374 (bodywork) Rush Racing - Tel: 01404 549696 (FMF exhaust) Big Four Engineering - Tel: 01663 734322 (switch gear) Bikes of Brighton - Tel: 01273 607635 (off-road clothing) Cambridge Motorcycles - Tel: 01223 360176 (dyno tuning) Vic Eastwood Motorcycles - Tel: 01322 669469 (Wiseco Pistons & official Honda components)