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Written By: Gardner Tarlow
The Church Of 350 Is Alive And Well!!
Why is it that the Austrian manufacturers are the only ones producing a 350cc motorcross and enduro bikes? In a sport dominated by vet plus riders on the track and trail, why wouldn’t more manufacturers provide a more balanced, rideable bike for the vet masses? I understand the allure of the 450. Early on I loved my 450 and yes, I was faster corner to corner and yes, I was jumping everything I shouldn’t be. After hitting the ground a few too many times, I eventually downsized to a 250F to limit my own stupidity from kicking my ass. I built a few 285s to try to compensate for the shortcomings of a stock 250 and although this helped close the gap with the 450s, the maintenance on a performance motor doesn’t make a lot of sense when you’re only racing for a $10 trophy. So, putting my pride aside, I’ve become resolved to claiming “I love my 250” because truth be told, a 450 is too much bike for my childlike brain.
Jump forward a few years and in early 2011 the 350 was born out of Austria and many of us thought our wishes had been answered. Could this be the answer to all the vet riders’ woes? From the early years of the 350, this was not the case. The early 350s felt heavy and slow for what the bike was supposed to be. Was the original 350 a faster, yet heavier and poor handling 250 or was it a sluggish, less powerful 450? Either way these early 350s missed the desired mark that the Austrians were shooting for. Each year the 350 has moved closer to being a performance bike with its own character but until recently without significant modifications the 350 was not optimal off the show room floor. The 2025 350 SX-F and XC-F may finally be the ultimate iteration of KTMs designers’ views of what they hoped a 350 SX-F or XC-F should be.
The 2025 KTM 350 XC-F has followed suit with many of the upgrades that the SX-F bikes have been receiving over the years and for 2025 the XC-F has nearly all the SX-F upgrades. Reworked frame, new airbox, new swingarm, improved suspension setting and the same usable proven performance that the most recent generation 350s have been designed with.
Starting with the new chassis updates from the factory racing efforts. The frame wall thickness near the front of the frame has been changed as well as the engine mounts have been renewed with cutouts that reduce rigidity. The area around the rear shock mount has also been updated and streamlined. These changes are designed to create improved flex for better cornering and bump feel.
The WP XACT closed cartridge spring fork and WP XACT rear shock on the XC-F have been updated with the reworked setting from 2024. Both the fork and shock have hand adjustable clickers on both ends allowing trackside adjustments without tools.
The 2025 350 motor remains the same high performing package from the 2024 version with small refinements to optimize performance. The transmission has also had small refinements and now uses 14/50 gearing. The electronics provide for both a green aggressive map and white, slightly softer power map, as well as launch control, quick shift and traction control. For full technical modifications and changes please see KTM detailed description on manufacturer site.
The 2025 350 XC-F is a closed course off road race bike. To most this would imply GNCC, Hare and Hound (with spark arretor) scrambles and the like. KTM has done a very good job providing bikes to cover every aspect of motorcycle off road riding. KTM also knows that not everyone will own numerous bikes and stretching a bikes ability outside its comfort zone sometimes is not optimal. We know this bike excels in its specified designed category but how does it perform on the fringe edges of its performance category? For those not racing this means open desert, open trails, tight single track, extreme enduro, moto, GP races, and everything and anything else you can do on a bike.
To break in and set up the 350 XC-F, I took it to Glen Helen and Cahuilla Creek over consecutive practice days over a few weeks. Being in SoCal with the early fall season, the hills and trails are dry and the only place to find good dirt is at the track. Having recently tested the 2025 Husqvarna 250 FC, this allowed me to have some very recent comparison notes to see just how much different the pure moto 250 FC bike was from a cross-country 350 XC-F.
The 350 XC-F bike is a surprisingly good bike on the track. The 350 motor is easier to ride, takes less energy and can be ridden like a 450 but really rewards the rider when ridden aggressively like a 250F. The 350 pulls hard off the bottom into the mid-range and continues to pull well on top. The 350 puts out plenty of torque and low-end power to satisfy those riders transitioning from a 450 who like to ride a taller gear. The motor isn’t a tamed down 450 nor is it a highly modified 250F. The motor really has its very own character that provides the best of both worlds of the 450 and 250F. There are two maps- white and green, with green being the more aggressive map initially. Both maps are linear in nature with the green map having more bottom end response and pull. I preferred the green aggressive map on all tracks, open enduro and moderate trails. The white map would possibly work better for moderately tight single track. The launch control makes gate drops more consistent and would be nice for GP and the occasional gate drops but I am not doing much of that. I am what Keefer calls a “Soul Rider”. The 350 XC-F shifts very well in stock form and although the quick shift is not really needed it does work very well when engaged. The traction control, I did not find any benefit while riding in any condition, motocross or endure so I have no real comment on that. It’s nice to have these features on the handlebar but for some of us, it really isn’t warranted, but it’s nice to “feel” like I will mess with these options.
Riding the 350 aggressively doesn’t seem as fatiguing compared to riding aggressively on the 250F. On the 250F it feels like you’re always needing to charge and be aggressive to keep the bike in optimal functional power but with the 350, errors or mistakes are easily covered by the bikes ability to recover and remain in the power. The stock gearing on the 350 is a 14/50 and works very well for moto. We tried a 14/51 at GH and although this worked well for pulling third gear in corners, second gear became very short, and more aggressive 250F style riding and shifting was required. For moto purposes the 14/50 seemed optimal. Side note, for open to moderate enduro purposes the 14/50 was also optimal and although the 14/51 worked slightly better for clutch abuse in tight single track, the 14/50 was better overall. The Brembo clutch feel is buttery smooth and functions very good. I had no problems with the clutch performance during both motocross, enduro and plenty of tight single track hours.
The suspension, although not designed for moto purposes, performed well in stock form. I weigh 185 without gear and consider myself a 60 plus B rider. I started with the recommended moderate suspension settings when I first got to the track but quickly adjusted to the stiff aggressive settings. Final suspension setting for the fork was 5 out on comp, 12 out on rebound and fork height at second line, not including cap line. The shock settings for me were 11 out LS comp, 1 out on HS comp and 12 out rebound, sag at 105mm.
The front forks are a closed cartridge spring fork and I really enjoyed the front end feel of a spring fork. The spring fork is very predictable and it is nice not dealing with air fork maintenance and break in period of an air fork like the FC250 I have been riding. The spring fork feels like it follows the ground better and I have more front-end feel on lean angle when entering corners compared to the air fork. The fork valving seemed very good for single track and enduro flattening out all the small hits felt with tree ruts, rocks and square edges when on the trail. I really like how the fork soaks up all the tiny chatter that usually wears out your upper body and can be the cause of fatigue on long rides. The fork is a bit soft for aggressive moto but with different valving modified for moto it would perform very well. The fork is plush and despite having the fork travel indicator showing full compression of suspension, I never really felt a significant hit to my wrists on hard landings or G outs. If the Austrians switched to a similar spring fork designed for their SX/MX on their SX-F class of bikes, it could be a game changer.
On the track the 2025 XC-F 350s handling is surprisingly good and very similar to the 2025 250 FC. These bikes share the similar frame modification updates from the 2024 versions so it isn’t a stretch that they are similar feeling. The 350 has good lean angle feel and transitions well into sections 2 and 3 of the corners. The bike likes being in the rut and doesn’t seem to want to climb out when transitioning onto the throttle in section 2 into 3. KTM has been working on the rear shock and suspension and seem to have a good handle on eliminating the squat effect in corners, which helps section 2 and 3. Acceleration bumps out of corners is surprisingly more comfortable on the 350 XC-F but this bike also has an 18” rear tire compared to the 19” on the 250 FC. Stability of the 350 XC-F was good on track and moderate speed enduro but for high-speed desert, I believe lowering the forks to 1st line or flush would be optimal. The 350 XC-F rear shock is plenty plush enough for trail and enduro, flattening out small chatter, soaking up G outs and big hits. The rear shock in the stiff setting (11 LS compression, 1 HS compression, 12 rebound) performed well on the track for my moderate pace but for larger or faster riders would need spring and re-valving. For this bike and its intended purpose, the overall suspension is very good.
Getting back to the fringe edges of this bike’s ability, we found some really good tight single track in north San Diego County. This was first and second gear riding with occasional third gear and very stop and go tight single track. To be perfectly honest, KTMs XC-W PDS two strokes would have been the optimal bikes and the tool of choice for this type trail riding. Although this is not the 350 XC-F designed intended purpose, it still performed pretty well in stock form. Initially, I tried the white map with traction control in the tight single track and this resulted in repeated cough and stall type episodes even putting me over the side of the bars once. Using the white map alone eliminated this repeated stalling effect somewhat but didn’t make the bike any easier to muscle around and ride. The bike in both green and white map still has a herky jerky slow pace motor feel that is throttle sensitive. This results in an uneven throttle sensation when riding slow rocky technical climbs or rock gardens. Due to this motor characteristic, there was a lot of clutch abuse on these trails and the bike started to overheat multiple times blowing steam twice. Obviously, this bike is not designed for this type of riding but my hope was that it would shine just as bright in tight single track as it did on the moto track. The 14/51 tooth modification helped for general clutch abuse in these tight conditions but accentuated the herky jerky on/off sensation and overall, the stock 14/50 gearing I believe was optimal.
I eventually made it out to our SoCal High desert hills with 12-24” trails with soft dirt, almost sandy long hill climbs, small rock gardens, and typical high desert rocky hard terrain. It was clear that the 350 XC-F was very much at home and performed very well. I could see many of the sections we ride in the high desert being within a less tight GNCC or Hare and Hound event. The suspension, both front and rear, perform really well not only addressing the constant trail chatter but handling G-outs and bigger hits. The small rock sections were easily maneuvered but again might be a handful if more significant or longer sections were encountered. I used both white and green map depending on technicality of sections and toggling back and forth was not an issue. The stock 14/50 gearing is optimal and the bike’s ability to charge up long hill climbs inspires confidence that makes you want to turn your trail day into a hill climb event. The bike really enjoys blasting up long hills but on long slower rocky hill climbs struggles to be as smooth as I would like.
This bike is about as close as you can get to a do it all bike favoring GNCC, Hare and Hound scrambles, GP, motocross and open desert. The 350 XC-F performs well in moderate speed single track, tolerates tight slow single track and would be a handful for all but expert riders for anything resembling hard enduro.
If this was my bike and I wanted a single, do it all bike, I would re-map (if we could jailbreak the stock box) the ECU with something similar to the stock green map for general use and a 2nd map designed for low end, very smooth, linear, tractor-like performance to optimize single track performance. This would be the easiest fix, otherwise I would consider a Rekluse auto clutch, which would improve many of the technical riding issues. I think the question still remains: Two strokes versus four strokes for that ultimate, do-it-all bike in stock form. Either way, the 2025 KTM 350 XC-F will help set the new standard in the open type of off-road riding
