We all know that the superbikes on the World (and British) Superbike grids are a far-cry from their showroom-spec brethren. They’ve got tuned engines, beefed up chassis, prototype suspension and carbon fibre everything. And that’s just scratching the surface. But whilst it’s true that superstock bikes aren’t nearly as trick as that, you might be surprised at how trick you can make them, and all within the rules. So if you’ve ever wondered just how fast you can make your stocker, join us as we ask, ‘how stock is superstock?’
You’d think the engine of a superstock bike ought to remain untouched, wouldn’t you. Well that’s not strictly true. Whilst you can’t ‘tune’ your engine, there are bits you can do to improve the motor’s efficiency, and therefor power. ‘Blueprinting’ is allowed and you can adjust the cam timing, provided you can do it without machining or drilling anything i.e. if the cam gears have slotted holes. All of the engine internals have got to remain standard and unmolested. You can fit an aftermarket exhaust though, as well an air filter and faff with the fuelling to get the best of them. A decent superstock bike will usually be between 5% and 10% more powerful than it was when it rolled off the production line. If it’s any more than that. People will start asking questions.
Chassis and Suspension
As far as the frame, subframe and swingarm goes, you’re superstock bike has got to remain very standard. If you can adjust the headstock angle (Kawasaki ZX-10RR) or swingarm pivot position (Aprilia RSV4) as standard you’re allowed to, but if you can’t, you’re not.
You can change the shock absorber, as long as it’s of a similar design to standard, I.e a monoshock. And you can change the fork internals too. The fork externals have to be standard, though. You can buy bike specific fork kits from Öhlins, K-Tech, Maxton etc. which is what most teams do. The suspension is probably the most important upgrade you can make to your superstock bike.
For a long time, superstock electronics had to be largely standard. You could run Power Commanders and other fuelling modules, but that was about it. A few years ago though, they changed the rules. Now you can run a ‘kit’ ECU and wiring harness. Not only does that let you bin off all the unnecessary (for a racebike) wiring (lights, horn, etc.) it lets you do a lot more with the electronics too.
With a Kit ECU, you can adjust all the electronic rider aids to the nth degree, faff with the fuelling and generally do what you please with the bikes electronics. All you need is a laptop, the right software and the right shaped plug. Whilst the kit ECU will allow you to raise the rev limit, if you do that to your stocker, you’ll get disqualified.
Tyres and Brakes
Some superstock classes (like British Superstock) have a control tyre. Others don’t. But the general rule is that the tyres used in Superstock racing have to be treaded. You also tend to be able to wets, if it’s raining.
Brakes-wise, there isn’t a lot you can do. You can change the wear parts, so pads and discs, but the mechanical bits, like the calipers and master cylinder have got to be standard. If the bike has ABS as standard, you can bin all that off. You can also upgrade any rubber brake lies to braded lines, and put top spec brake fluid in them.
There are a few other bits you can do to your ‘road bike’ to turn it onto a ‘superstock bike’. You can run captive spacers in the wheels to make getting them in and out easier. Lights, horns and all that garbage can be thrown in the bin. As well as all the standard road bodywork. You can run carbon fibre race kits if you want to, but not many people do, instead opting for cheaper fibreglass kits. The only stipulation is that the bike has to match the silhouette of the standard machine. You can swap all the controls, so footpegs, handlebars and levers. You’ve got to run a lever guard if you want to go racing. It’s a good idea to slap some engine protection on too.
And that’s about it. And if that doesn’t seem like a lot, try paying for one. You’re talking about the thick end of £15,000 to trick a showroom-spec bike out to superstock-spec. That’s on top of the cost of the standard bike. It’s not cheap. But it’s a fraction of the cost of a superbike.