Feisty Frenchie

"Can cost-effective mods and set-up tweaks transform Sherco's 300SE-R into the best 300cc two-stroke on the market? We didn't want to die wondering."

2015 Sherco 300SE-R feature in Transmoto Issue #49

19/03/2015

Written by Andy Wigan
Photography by Andy Wigan & Kurt Teague at Transmoto

It’s hard not to pay attention to what Sherco is up to these days. Consider what the dynamic young French manufacturer has achieved in the past three years alone. In 2012, they released their new-gen 250/300cc four-strokes, both of which have now been refined into world-class enduro weapons. In 2013, they launched their first ever two-stroke models: an immediately competitive 250 and 300SE-R.

In 2014, three members of the ISDE winning French team were Sherco mounted (as was Australia’s Jess Gardiner, who won the Women’s class). And for 2015, Sherco unveiled an all-new 450cc four-stroke – a machine that’s already tasted stage-win success at the 2014 Dakar Rally – and made substantial upgrades to its entire two- and four-stroke range. So, for a relatively small manufacturer, Sherco is sure punching above its weight! And it’s that growing cred that prompted us to put a Sherco 300SE-R on our long-term test fleet for the first time. We wanted more of an insight into not only the performance of the brand’s flagship two-stroke, but what it’s like to live with and maintain over the longer term as well. In other words, we wanted to replicate the average ownership experience.

In our recent 300cc two-stroke shootout (featured in the Nov-Dec issue), I surmised that Sherco’s 300SE-R had enormous potential and was only a few set-up tweaks away from being a class-leading machine. So, now that I’ve been given the opportunity to perform those tweaks, have I been able to develop the bike into a class leader? Well, here’s an insight into what I’ve done to the 300SE-R T-Ride and why, and how it’s improved the French machine’s performance and/or durability...


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MAKING BETTER POWER

In our recent 300cc two-stroke shootout, we said, “...the Sherco’s power delivery is more akin to what you’d expect from a 250cc MXer than a 300cc enduro bike. This makes it an exciting machine to punt around a fast and flowing grasstrack where there’s plenty of traction. But in tight terrain – where a more controlled surge of smooth power is called for – the Sherco can be a handful.”

As Sherco’s design team had worked specifically on the powervalve and ignition settings to create a smoother and more progressive style of power for the 2015 bike, the brand’s Australian distributors were understandably disappointed about those comments. What’s come to light since we went to print with that shootout article, however, is that there was an assembly problem with that test bike’s power-value mechanism. With one of its booster ports opening inconsistently, the power curve was nowhere near as progressive and user-friendly as it should have been. Unfortunately that compromised the integrity of our shootout’s feedback, and it didn’t reflect too positively on Sherco either. And that’s why it made a lot of sense for us to get that same test unit as a long-termer; so we could have the power-valve issue addressed and gauge the improvement.

Suffice to say that, with the powervalve operating as it should, the difference is night and day. Instead of a big hole in the SE-R’s power off the bottom and an abrupt midrange hit, the bike has now got a much torquier and responsive surge of power from low RPMs, and a smoother transition into the midrange. And that makes the machine more willing to be to short-shifted and a lot less fatiguing to ride.

I leaned the jetting off slightly by dropping the standard N8RG needle to the second clip from the top and ensuring the air screw was 1.5 turns out. This creates a crisp and responsive feel through the entire rev range, but doesn’t make it ping or run-on into corners. JD Jetting has just released a kit for the 300SE-R, so I plan to play around with that and see if I can get it any better again.

While the standard 14/49 gearing sounds pretty tall (and it is good for 150km/h in sixth gear), I can still carry third gear through most tight singeltrail and keep the bike torqueing along smoothly. That said, I do know that several owners reckon a shorter 13/49 or 13/48 final gearing combo works well, mainly because it lets them get the bike into third gear earlier, so I plan to trial a few shorter gearing options over the coming months. And with the Sherco’s handy offset axle adjuster blocks, I should be able to do this without having to remove links from the chain.


SORTING THE SUSPENSION

While the 300’s WP fork and shock both work well in isolation, it does take a little trial and error to get the chassis balance right and create a harmonious feel between both ends. But when you do, it makes the machine much more manageable over a wider variety of terrain. As several Sherco dealers are reporting, the 300SE-R tends to work better with a little more sag in the rear-end. Rather than the manual’s recommended static/race sag settings of 30mm/95-100mm, I settled on a 36mm/106mm combo with the shock. Even with these settings – combined with the fork in the standard position in the triple clamps (the second line from the cap) – the bike still steers sharply. But it gives you a little more high-speed stability and really helps the rear-end squat, hook up and drive more effectively on bumpy corner exits.

While heavier blokes (over 90kg) all seem to be fitting a heavier shock spring to the 300SE-Rs, I reckon the stock 51N/mm unit is still suitable up to about 95kg. A firmer spring is often used as a quick fix for a too-soft shock setting, but since the sag numbers are right with the standard 51N/mm spring, I plan to initially firm up the shock’s mid stroke and bottoming resistance through valving, not the spring.

In the meantime, I’ve found the shock likes a little more high-speed compression damping (1.25 to 1.5 turns out) and a few added clicks of rebound damping (9 out) to settle the rear through a series of big braking bumps.

But the biggest benefit of running a little extra rear-end sag is that it creates a more neutral chassis balance, which stops the fork from riding too low in its stroke through a set of braking bumps and/or tucking when pushing hard into tight turns. Even though the same WP fork in the KTM 300EXC (which runs the same 4.4N/mm springs) doesn’t like extra spring preload for faster or heavier riders, the Sherco’s fork seems to. I’ve found that dialing an extra two or three turns of fork spring preload (from the standard four turns) helps the Sherco’s WP fork sit up into the plusher portion of its stroke (remember that with fork’s spring preload, the turns are made from all the way out – that is, no preload – rather than all the way in). A little extra damping on both the compression and rebound clickers (10 and 10, respectively) also seems to work well for my weight.


NEXT TIME AROUND…

Stay tuned for the Stage 2 article in two issues’ time. By then, I will have fitted a few more cost-effective protective parts (such as Force’s new billet Radiator Protectors), tested alternative gearing, dialled the WP fork and shock, and played with the electronic power-valve to get a fix of how effective a tuning tool it can be. In the meantime, you can keep abreast of the bike’s development via www.transmoto.com.au



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