Manufacturers have always liked to convey the impression that World Superbikes are just like the machines you can buy in your local showroom. However, the reality is that nothing could be further than the truth. The WSB rules are effectively 'silhouette' rules, meaning that as long as the bike looks the same, and a few other components are kept, it's basically anything goes. We are talking highly developed engines, modified chassis, top spec suspension, lightweight wheels and the rest. But Superstock is very different. In theory these are basically road bikes made into racers with minimal effort. However is this really the case? PH2 was given the chance to find out by taking the BMW Motorrad GoldBet World Superstock racers for a spin around Imola.
A quick warm-up on the standard bike first
BMW has been pushing its HP Power Parts range of accessories and the GoldBet team use these products on its racer. So, starting with an
HP4 as a base
Frame
The frame and swingarm are 100 per cent the same as the road bike. PH2 checked and sure enough, there is even a VIN number stamped on the headstock. Although the suspension linkage is the same, the HP4 allows for different swingarm pivot angles through adjustors, so this can be altered to one of three different settings. As with any race bike, the team can alter final drive sprockets and fit a 520-pitch chain.
Engine
The teams are only allowed three engines per season, and each one is sealed and marked by the WSB scrutineers. BMW blueprints the engine but that is it, aside from altering the cam timing and fitting a thinner head gasket to raise compression. No metal is allowed to be added or removed from the engine. The final result is between 190 and 194hp with 88lb ft of torque with an Akrapovic titanium exhaust and race air filter.
Before switching to the race machine - gulp
As far as electronics go BMW's HP Power race calibration kit plugs into the standard wiring loom, allowing the team to alter all the parameters of traction control, ABS, fuelling, launch control, DDC and the rest. A very cool plug-in unit replaces the key, meaning the team can't lose it!
Suspension and brakes
And suspension? The HP4 runs the semi-active suspension system (DDC) and the race team are also now using this. The rules require the valves and internal hardware remain standard, however the team can alter oil level and spring rates. The DDC links in with the GPS race calibration kit and can alter its settings at specific points on the track.
Brake calipers remain the same but the pads and master cylinder can be changed. GoldBet uses the OE BMW discs, although they can also be changed.
And the rest? Rear sets, race bodywork, a quickshifter, race clip-ons, a quick release fuel cap (no key required), Pirelli SC tyres, crash protection and one mental rider and that's it, you are away...
Jon certainly looks the part on the Superstock
After a few out laps on a stock HP4 I swapped over to the GoldBet bike with a fair degree of worry. Last year
I rode a Superstock S1000RR
and it was probably the most hideous and awkward bike I've ever been on - all up at the front, low at the back and flighty over bumps. Things have changed remarkably in just 12 months.
As soon as I left pit lane I started to feel at home on the racer as despite feeling very solid and flat, the superstocker was remarkably easy to ride. Unlike the HP4 road bike's seat the racer's foam padding made moving around the bike tricky as it was quite sticky. However, once you get over this initial feeling of being 'trapped' on the seat it's an absolute joy.
By using the semi-active suspension, BMW has taken the weirdness out of the racer's handling. Well, weirdness if you are used to road bikes. It still feels very firm and flat when compared to the HP4 road bike, but it isn't anything like as alien as the 2011 machine. Or unstable.
Get it up
Driving up the hill out of Acque Minerale was the only place the racer started to get a bit interesting and slappy, although this was simply down to the incline putting all my weight over the rear and unloading the front. The HP4 road bike also got a bit loose here, however the stocker was noticeably more unsettled, something that was certainly due in part to the engine's performance.
Race bike demands weight on the front wheel
With a claimed 190hp at the rear wheel, the stocker makes about 20hp more than the road bike. Although not feeling remarkable more powerful, the racer certainly accelerates with more eagerness (gearing could also be a factor here) and happily lifts the front in third gear up the hill on the throttle. Luckily the brakes are pretty fierce as the Variante Alta chicane is more than a touch tight. Which brings me to the handling.
As with any race bike the superstocker is designed to be nailed into corners rather than wallied around by someone like me and it is only when you start to really force the front into bends that it works properly. Oddly enough I found adopting the 'lean forward over the front' riding style that you see racers use made the bike feel much better in bends, even though I probably looked pretty stupid. And slow.
Just like the one you can buy yourself?
In fast corners the amount of confidence in the front tyre the handling gives is incredible and it also flops on its side remarkably quickly through the chicanes. With the HP4 road bike I found the back end felt a touch soft during quick direction changes, a trait the racer doesn't display - which may be down to the electronics. According to a technical chap, the BMW's electronics were altering the DDC's suspension settings mid-lap, giving it a different set-up for the tight chicanes to those for faster corners. Could I honestly say I felt the suspension alter? Not really, but the bike certainly felt 'right' at every corner and more settled than the road bike.
So, how close is the stocker to the road bike? Looking at the specs they are extremely similar but to ride they are very different animals. The stocker's engine is more eager, the handing has a greater focus and the suspension is more suited to track use. Which is hardly surprising as this is where all its development is targeted. What I found so surprising is just how few changes it takes to convert the HP4 road bike to this track machine. The clue is in the name, after all!