Despite European laws clamping down on two-stroke dirt bikes, Sherco is keeping the carburettor for the 2020 models and in the future – we ask the French manufacturer's General Manager, Thomas Tessier, how come?
The 2020 Sherco Enduro model range has many standout features but chief among them is the performance of their two-strokes. If you’re looking for proof check no further than the performances of Mario Roman and Wade Young in the Extreme and Hard Enduro circuit.
Under-pinning the performance of their two-stroke models is the continued use of carburetted engines. In a world where emissions laws are clamping ever tighter on the two-stroke, the question is: how can a manufacturer keep going with the carb?
Who better to ask than Sherco General Manager, Thomas Tessier…
The first and important question is, why do we not see a fuel injected two-stroke engine from Sherco?
Thomas Tessier: “The Euro 5 rule won’t come in to effect until 2024 so there is a long time until we are obliged to have fuel injected two-strokes.
“Also, we like to consider the customer as a friend, so there is no way that we are putting an evolution in the market that doesn’t mean a step forward in bike’s performance.
“There is no point in putting a fuel injected two stroke bike in the market if it’s not going to be better than the current carburetted one. It’s also more expensive so it makes no sense at the moment. Charging the customer more for a product that doesn’t deliver a higher performance makes no sense.”
This cannot last forever of course; the Euro 5 law will mean a different situation…
“We still have time until 2024 – when injection will be mandatory – so when we have the injection working correctly, we will bring it to the market.
“We know that the two-strokes need to evolve but it is important to notice we have approached it in a different direction [on current models].
“We have implement the ‘SBS’ system, our in-house developed electronic power valve, that has the valve’s engine fitted directly in the cylinder, we are the only brand that does that, and with the map selection switch on the handlebars it means a five to seven horsepower difference. That’s a real improvement on the product.”
You have developed the fuel injected two-stroke already though, right?
“We have a fuel injection system developed and if anyone searches for it on the internet they will see videos of the bikes with fuel injection. But at the moment we’re working on something a little bit more simple – like we saw with the SBS power valve we have acknowledge that the future is going towards more simple technology.”
It is fair to say the system you use is not just a simple carburettor set-up…
“The SBS, electronic power valve, works in relation with the RPM managing a percentage of the valve’s opening. With the map selector we also manage the ignition and the opening of the power valve, that’s why there is a big difference in horsepower [between maps].
“Other engines with a mechanical power valve open it really quickly in relation to the engine speed. With our system we can have the same opening percentage in 6,000rpm or 10,000rpm, it’s not mechanical any more.”
So at the moment the bike meet the Euro4 standards and clearly the 125, 250 and 300 two-stroke Shercos can put their power down the ground pretty well.
“I think that the bikes’ good performance has been translated to our race results. This year we have changed a lot the thermodynamics of the bike and it’s much smoother now. Our riders wouldn’t have managed to win that many events this year (2019) if the bike wasn’t good.
“The people will say that’s the rider and not the bike but I think that we have both, good riders and good bikes. I don’t like to say that our bike is the best but we have had three podiums in major races; Alestrem, Lagares and Erzberg so it’s up to the customer if they want to choose this product or not.”
Photo Credit: Sherco Jon PearsonEnduro21 Editor and Bike Testerjon.firstname.lastname@example.org