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Tested: KTM’s 2018 SX85

It’s not often that a manufacturer wheels out a totally brand new 85cc two-stroke youth race bike. New as in new engine, new frame, suspension, bodywork – the lot. It always seems like youth racers get the short straw with bikes that don’t change for decades, apart from the odd spruce-up.

But for 2018, KTM has stepped up to the mark with a totally new 85. It’s not like their current bike had problems, as it was by far the most popular machine on the tracks of the world. Sibling firm Husqvarna, which shares the same basic components, is popular too. The odd exotic TM shows up, or old Suzuki. But apart from that, there are a few Kawasaki and Yamaha 85s around but these definitely have their roots in old bikes.

And with many of the youth racers being obsessed by the coolest and latest kit, making a brand new bike is an obvious way to dominate the market even more.

The 2018 KTM 85SX – available in small and big-wheel versions – has a new motor with more power and weighs 0.69kg less than the current bike. There is a new, lighter steel frame and subframe, WP AER 43 air forks and a new WP Xplor PDS shock for its linkless rear suspension. Perhaps the most surprising thing is that KTM sticking with the PDS linkless system, as all its motocross bikes now have linkage rears. But PDS is light, simple and effective.

To match the all-new chassis and motor, there is a new exhaust, rear brake caliper, no-dirt foot pegs and gear lever, ODI grips and a new throttle housing. But the heart of the bike is the engine. The old engine was built for KTM by Beta, but the new motor is an in-house KTM unit and is totally different.

Our mini test team!
Our mini test team!

It has gone through the same thought processes as the KTM big bike range went through a couple of years ago, which was all about working out where the engine and crank should be placed to maximise mass centralisation to make it feel lighter and more flickable. So the motor has new crankcases, cylinder, power valve system, clutch, gearbox and crank shaft.

And it’s the motor that’s by far the biggest talking point when we assemble our crack team of mini bike testers at the Apex track to try out the new bike. The old KTM model was very fast, but you had to keep it on the boil to get the best out of it. The new model feels very different, with more down-low grunt that’s far easier to ride for the majority of riders. All the riders raved about the instant response the bike now has out on track. When the KTM rips past, the motor even has a different note to the previous model. It sounds deeper with more bark.  Here’s what our trio thought about the bike.

Leon Ongley – the small-wheeler kid moving up

Leon is normally a 85cc small-wheel rider but on this occasion he tested the KTM85 big wheel. He moves up to the big wheel class at the end of this year and he currently rides a Husqvarna TC85. He’s a big lad and he doesn’t look under-sized on the big wheel now.

He really gelled with the bike and instantly loved how it felt out on track. He was quick to mention the bike had a good response from bottom and that it pulled better than the bike he’s been racing, which has some modifications anyway.

Leon styles for smiles!
Leon styles for smiles!

He liked how the bike felt and mentioned it felt very light in the air. Leon thought it was a big step forward from his Husky in pretty much every aspect. It was surprising for him to say that bike had such a good hit from the bottom as the bike he’s been riding has little wheels, which often help with instant acceleration. You’d have thought Leon would have mentioned the top end over the bottom being sharper than his current bike, as the big-wheel bike usually feels faster at top end once you get the wheels rolling. But it’s testament to the bottom-end grunt of the new KTM.

Just about the only thing he didn’t like was the AER air forks though. He thought the action wasn’t as good as the spring forks in his Husky.

Callum Pickles – the Yamaha regular

Callum is currently riding a Yamaha YZ85. But as he’s fresh out of the 65 class, he’s no stranger to the KTM brand. But he did think the KTM felt taller than the Yamaha when he first got on the bike.

Out on the track, the first thing Callum picked up on was the throttle response. He said the power delivery was good and it had a lot of bottom-end power but he felt it was a little slow on the top end as the power dropped off.

Callum goes for it
Callum goes for it

He liked the suspension and he like how light the bike felt but he struggled a little with the overall feel as he felt he sat on the bike rather than in it like his YZ85. Callum ended the day not being a KTM convert. Even though he liked the bike, he’s staying blue which dad was very happy about!

Max Smith – the new KTM owner!

Max has been riding a 2015 KTM 85 after moving up from a KTM 65 last year. So was looking forward to testing out the new 2018 KTM 85. And he liked it so much, he now owns one! So that’s a huge testament to how much confidence he had in the bike and his riding certainly improved during the day.

He spent time getting the suspension set up to his liking and light weight, and you could see this gave him more confidence to start to push even harder – really getting low in the corners and whipping it over the jumps.

Max said he thought the bike was far easier to change gear on than his current bike, but he did miss a few shifts during the day. He said it pulled from very low down in the rev range. Max thought it was easier to get out of the corners due to the power delivery in the bottom and mid range, and loved the suspension which he thought was a lot better. He thought the forks were good, even compared to the modified forks on his 2015 bike.

Max air time!
Max air time!

He raved about he brakes, saying you could really brake late into the corners. He even said he didn’t need to modify the bike in any way to race it – so that’s obviously makes it a winner!


The bike may not be much lighter than the older machine, but it certainly feels it. All the testers said how light it felt, how easy it was to move around on and how the low and midrange power really suit the new, more flickable feel.

The very fastest riders might miss that it doesn’t have the mad top-end rush of the old bike, but it’s easier to modify a bike to give it more top end if the rider really does need it.

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