Words : Jonathan Pearson
KTM 350 EXC-F

KTM’s 2020 EXC range burst onto the scene with a bang at the World Press introduction in Bassella, Northern Spain. The process of evolution in the KTM off road range saw the motocross models undergo major changes last season and for 2020 it is the turn of the EXC Enduro bikes.KTM has applied a long list of changes across the now seven-strong line-up which includes new frames, updated WP suspension, heavy work on both two and four stroke engines, new bodywork design and ergonomic changes all aimed at improving performance and rider experience. Jumping back into the EXC Enduro range for 2020 is a brand new, fuel injected 150cc TPI homologated for Euro 4 and which joins the 250 EXC TPI and 300 EXC TPI two-strokes, as well as the 250 EXC-F, 350 EXC-F, 450 EXC-F and KTM 500 EXC-F four strokes to complete the KTM enduro range.

KTM 300 EXC TPI Erzbergrodeo Edition

The 2020 EXC range also extends, as ever, to the SIX DAYS models along with a new, limited-edition, KTM 300 EXC TPI Erzbergrodeo Edition with a production run of 500 units. Taking place at the very top of Spain under the shadow of spectacular mountains that stretch north into the Pyrenees range, the MY2020 EXC Enduro launch was hosted by Bassella Experiences, the location for one of Spain’s biggest events as well as their off road experience days, plus home to a new motorcycle museum.

Testing starts early on a KTM new model launch, with a lot of bikes to fit into a long day’s riding we start with a bike which has already been put to the toughest test at the infamous 2019 Erzbergrodeo, the 300 EXC TPI. Familiar to so many, it is KTM’s biggest selling enduro model and proves the point that two-strokes, and in particular, the Transfer Port Injected models are very much at the heart of off road motorcycle sport.

The 300 EXC TPI engine stands as favourite with traditional and extreme enduro riders because of its versatility and you really feel that from the get-go with the new model – each increment of the throttle twist grip delivers a precisely different amount of power across the varied Bassella terrain test course. The evolution of the TPI engine for the MY2020 models includes a new ambient pressure sensor and 39mm Dell’Orto throttle body working together with the power valve, a reworked idle system supplying more air (and improving cold starts) and a redesigned air intake funnel to deliver a more precise power delivery.

KTM 300 EXC TPI MY2020

They are each important elements of a bigger picture aiming to improve responsiveness and efficiency of the engine. MY2020 TPI engines get their cylinders upgraded with fully machined exhaust port windows for improved timing precision. At the same time, a reworked exhaust control valve drive and adjuster produce more precise adjustment and increased efficiency. 

One major element in terms of feel for power are the new exhaust systems. KTM says their engineers put a lot of effort into developing the exhaust for all 2020 EXC models and they are key factors behind the improved power delivery you can quickly feel on the bike. 

The new, heavy duty exhaust pipes use an innovative 3D stamping process that makes it possible for that distinctive corrugated surface. The results is an exhaust pipe which is slimmer and more resistant against impacts, while significantly reducing noise KTM claims. 

It is easiest to feel that performance difference when you jump on the 250 EXC TPI. Naturally the 250 lives better in the mid-range so it makes for a more attack-minded bike. If the 300 is the favourite for many riders at events like Erzberg because of its range of power then the 250 is in its element in a classic enduro test. Where the 300 makes you feel capable, the 250 is encouraging you and telling you to go faster!

KTM 500 EXC-F MY2020

Riders like Taddy Blazusiak and Jonny Walker, present on the MY2020 EXC launch, were each part of the development process from the very earliest TPI bikes to the latest models. Their constant demands, as much as any, caused a great deal of work in the software development for these new models which have the latest versions of ECU engine mapping.

Another one of the development changes which the factory racers played a part in is a new lateral engine headstay which is one of those parts on a bike which you think, as a normal rider, you cannot possibly feel. New on all models, the metal part connecting the cylinder head to the frame is contributing to cornering precision while reducing vibrations KTM says. 

Rupert Walkner, who is charged with so much of KTM’s R&D on the off road range, says everybody can tell this difference: “you would be surprised the difference to change this part. Anyone can notice it.” Explains Walkner.

KTM 450 EXC-F MY2020

By now in the launch test it was also becoming clear there’s something different about the way the new models handle on the track. New valving inside the forks plus that engine stay stiffness change and an increased amount of lateral torsion applied to the area behind the headstock in the main frame each contribute to improved feel for the front end of the bike across a range of riding conditions.

There were some tough ruts forming into corners at the Bassella course after so many riders and bikes that you really needed to hit the line to make the turns and all models showed how accurate the new chassis can be even when braking bumps are trying to throw you off line. 

The press presentation noted the engine has moved in the chassis, just by a single degree rotated forward on the TPI models but along with changes to the position of the radiators (dropped by 12mm), it has helped the character of the bike to change subtly for the better.

Tackling some of the Bassella course’s tough downhill sections proves the point about slimming the ergonomics of the 2020 bikes too. The 2020 rear fender is 40mm longer but with the new rear mufflers the feeling space and control between your legs as you hang off the back of the bike is also improved.

KTM EXC SIX DAYS MY2020

All EXC models are fitted with the WP XPLOR 48 upside-down fork as previous with the split fork design delivering separate damping circuits – the left-hand fork damping only the compression stage and the right hand one only the rebound. 

For 2020 the fork has a new, mid-valve piston for more consistent damping, as well as new clicker adjusters on the upper fork caps for easier adjustment. 

On the track the effect of this new setting keeps the front end a touch higher as you track through the trees with less tendency to dive. When you transfer hard onto the front under braking or downhill sections, there’s a sense of increased bottoming resistance which gives more confidence on the brakes. 

Standard on the SIX DAYS models and optional on the standard models, the three-stage spring preload adjuster are easier to use now without tools as well.

KTM EXC MY2020 FAMILY

Hot on the heels of the EXC TPIs is the 350 EXC-F. Many people’s favourite EXC simply because it feels like a great balance of power, weight and handling.

Like the 300 2T, the 350F delivers power that can be docile and careful or it can give you the “grunt” when you want it which is why so many from racer to hobby riders like it – at once a really enjoyable trail bike that is just as ready to take you racing at the weekend. Having that range of power at your right hand gives you the flexibility of using one or two gears for long periods like the bigger four strokes, but it is still ready and lively if you want to switch it to beast mode.

It comes as a surprise how usable all the four strokes are despite their quite different characters. The bigger machines, the 450 and 500 EXC-F particularly, are great at tracking and sticking to a line along the faster sections of the course or the rocky up hills when you’re driving on the gas to make it to the top – in those circumstances the planted feel and grip is very welcome.

Part of that planted feel is down to a new WP XPLOR PDS (Progressive Damping System) shock absorber. For MY2020 a new second piston and cup in the shock increase resistance against bottoming, to match the forks.

KTM 250 EXC TPI MY2020

The bigger EXC models like the 500 are really good at letting you stick in one or two gears, second and third mostly, and simply use the strong and torquey power from low to high revs. This was also the bike which showed off the new seat best of all. A slightly different shape and new foam inside make it more comfortable and grippier.

The 2020 KTM 450 and 500 EXC-F engines have perhaps the biggest changes with a new, more compact SOHC, 15mm lower and 500g lighter cylinder head. Re-designed ports on the bigger 4T engines are controlled by a new overhead camshaft closer to the centre of gravity to improve handling. New intake and exhaust ports, and more rigid rocker arms produce more consistent performance. An improved axial mount for the decompressor shaft means more reliable starting and a new, more efficient integrated engine breather system reduces oil losses. All now also come with a fan as standard.

One thing you notice on the trail is the big bikes rev more freely and that in part is down to the short cylinder with a 95mm bore housing a new, lightweight box-in-box type piston made by König with a 10% lighter piston pin, which KTM say improves performance and engine speed strength but lowers vibration. The compression ratio is also increased from 11.7:1 to 12.75:1.

It is a lot to take in but the message is clear out on the track; the big bikes get easier and easier to ride and like we said earlier, that ability to stick in one gear, especially on the 500, is a real bonus.

Revving up to a claimed 12,800rpm, the MY2020 250 EXC-F is a different beast to the 500. With a new 78mm bore cylinder and raised compression ratio from 12.8:1 to 13.8:1 you can tell that in part the development for this bike has carried over from the successful KTM 250 SX-F motocross engine. If the 450F can at times feel like a bike for the pro rider on a race track the 250F makes you feel like a pro. 

KTM 150 EXC TPI MY2020

Weighing in a little differently on the scales is KTM’s 150 EXC TPI. Nowhere does the new Kiska-designed more ergonomic bodywork, reshaped tank and lower radiator position come across more obviously than on the all-new 150 TPI. First impressions of the 150 are like getting on a slightly heavier E-MTB bike! It really feels so manageable, flickable and light it is hard not to enjoy yourself riding it.

The new 150cc EXC TPI engine takes onboard all the attributes of its larger capacity, 2T model siblings and with an e-starter system too, it is a treat to ride. 

The 150 is aimed at a wide range of riders and you shouldn’t be put off by the capacity because it is a really capable bike. The linear nature of the TPI engine, even with 150cc means you have access to torque and though you make many more gear changes on the track than with the other bikes, there is more power across the rev-range than you expect. Riding the 150 is a lesson in being in the right part of the revs and if you are keen to improve as rider this is the bike to learn the craft of enduro.

Like the bigger capacity TPI models the throttle response is quick to react adding to that agile feeling and much like the 250 EXC-F, the 150 is a bike you feel like you can push to greater limits on a track. 

In short it is a light and lively two-stroke with all the reduced weight benefits that a small capacity two-stroke brings plus the low-maintenance benefits and proven reliability of the TPI model.

If you’re looking for a new part on the 2020 models which customer feedback contributed towards then the newly designed oil tank with more flexible mountings for enhanced durability is one. The outlet is also now fitted with a mesh filter to protect the oil pump from dirt intake. Another element is the reworked wiring harness which concentrates most of the electrical components in a single area below the seat. Finding the electronics are more easily accessible or the routing of the throttle cable is improved matter to the customer and KTM has listened.

KTM continues to develop its EXC Enduro range and increasingly the breadth of development includes software as much as it does hardware. Changes to chassis for MY2020 have delivered a very real improvement to the handling across the EXC range which now turn better, deliver more feedback to the rider and hold lines with more confidence whether you’re on a single track or wide gravel road. The engine changes across all models have increased the usable power available on all two and four strokes – and that includes the feisty, new 150 EXC TPI. 

Significantly for 2020, the TPI 300 and 250 models have evolved in this second generation to keep pushing two-stroke enduro motorcycles forward to remain at the heart of enduro. 

2020 KTM EXC models will be arriving in dealers worldwide from June onwards. 

For more information visit www.ktm.com