2017-2018 SERT XRJ-1
SERT’S NEW racer represents more than just a shift to the latest model: a benefit in itself, with higher base power and a better chassis to build a bike from. It represents the change in attitude SERT and their rivals have unwittingly forced themselves to make – years of incremental bike development and an influx of jobbing sprint racers offering their services for valuable extra riding time, pay packets and sponsorship opportunities has elevated the standard of bike and riding required to win.
SERT didn’t develop this bike: though they ran a Junior, Superstockregs new model in 2016/17 (EWC starts at the Bol Dór in autumn and the series runs to the following year), the Superbike-spec bike they’re campaigning for the first time in the 17/18 championship arrived in boxes from Suzuki Motor Corporation Japan... and Yoshimura.
In fact, it’s not even called a GSX-R really – the code for this true factory machine is XRJ-1. That doesn’t quite mean what it once did: rules for most series dictate standard rods, pistons, etc, so the engine is the closest part to standard. But the rest is true money-can’t-buy stuff.
The chassis is a Suzuki Motor Corporation part – machined at the swingarm pivot and headstock to take inserts for adjustment of head angle and pivot height. The 24-litre tank has a subtle Yoshi logo in the sheet aluminium: not only does it give volume, but it carries the weight low and central for better steering. The seat unit and fairing are SMC specials: following the silhouette of the road bike but with bigger side panels (covering the tank’s Johnny Vegas-style low hanging gut) and bellypan. Magneti-Marelli electronics are SMC-developed to suit. Suspension remains Öhlins TTX; brakes are factory-supported Nissins.
The gain in raw numbers is significant: even in 24-hour spec, it’s making 215bhp, with the capability to dial in 220bhp for the shorter events. That puts it on a par with BMW’s Type 6.2 engine. Weight is bang on the 175kg minimum – after SERT got involved.
“We had to ballast the bike to meet the minimum weight, but it does mean we can afford to use stronger rearsets,” Dominique says.
Development and testing has centred around honing the sprint/ Suzuka Eight-Hour-developed basics supplied by Suzuki/ Yoshi to work over 24 hours. Much of the architecture is retained – no super-strength subframe here, and some of the crash-ready touches traditionally used by teams are omitted in favour of outright speed.
“We’ve changed the mapping for endurance – for fuel efficiency, and also our engine braking strategies and throttle response. The new engine is so much more powerful. The old bike always compromised grip and agility, but the new bike maintains both together. We’ve had to do some work to make it work with Dunlop tyres, because it was developed on Bridgestones.
“More precise electronics allow us to get the exact setting we want. The traction and wheelie control systems are better, with more precise sensors; they’re more expensive if we break one, but worth it. It’s ready to win races – the base bike is very good, we just need to prepare it well for 24-hour races. For example, we simplified the lighting connectors from three to one to make it easier to work on and repair.”