KTM recently announced the information on 2015 lineup of motocross models, which features a number of engine options, including both the two- and four-stroke motors. Many 2015 models feature a host of changes as well, which include updates such as new chassis and suspension upgrades.

For 2015, KTM has retained its chromoly steel chassis on its motocross models, refusing to shift to the aluminum-chassis design used by other dirt bike manufacturers. For 2015, KTM will rely on a chassis built by KTM subsidiary WP Performance Systems that features chromoly steel sections that are paired with a new cross tube that features non-welded, machined connectors for the linkage rods to the frame. The machined design is said to be more exact in regards to production tolerances, giving chassis more consistent characteristics than the welded design. It also shaves 58 grams of weight from the chassis.

KTM will also employ a new cast-aluminum swingarm, which features wall thickness has been refined for minimum weight while providing optimum stiffness. KTM says it paid particular attention to the flex characteristics of the swingarm to ensure excellent traction, stability and rider comfort.

KTM has also added a fully adjustable rear monoshocks to the 2015 SX models that were developed by KTM in-house supplier WP Suspension. The new shock is re-valved and desgiend to compliment the new linkage geometry. WP Suspension lengthened the shock stroke 4mm, though it will provide the same amount of wheel travel because of a new linkage design that was developed with the Red Bull KTM Factory Team and KTM’s US R&D department.

For 2015 U.S. models, KTM also fitted the front of its SX models with a new WP 4CS fork. This new, four-chamber fork has been specifically designed and tested for motocross, and it is designed to offer improved damping, is lighter than previous models and can be adjusted easily for compression and rebound simply with the dials on the top of the fork tubes.

New Features and Revisions
For 2015, the front axle has been reduced in size from 26mm to 22mm to reduce weight and offer a better front-end feel. The smaller axle also made it possible to move it back 2mm in the axle clamp. The adjusted offset and increased trail is claimed to provide more stability.

The fork protectors have been revised for 2015, primarily to fit to the new axle clamps but also to save weight. They also allow easier access to the fork legs for quicker cleaning and faster maintenance.

CNC-machined triple trees have been a KTM trademark for years. For 2015, KTM slightly revised them by altering the O-ring support for the lower bearing on the steering stem. It is now made of aluminum to save 22 grams of weight, and the steering stem bolt is also 8 grams lighter.

The main focus of the KTM’s bodywork was to achieve complete harmony between rider and bike, right down to the finest details. KTM says that the front fender is a prime example of a molded polymer component, gaining maximum stability through a well thought-out structure and mounting system. For 2015, the bodywork will be decorated with updated graphics.

The 2015 SX models also receive new Excel rims colored black for aggressive looks. The rims are mated to lightweight CNC-machined hubs via Excel spokes with lightweight aluminium nipples, and they are wrapped in Dunlop’s excellent Geomax MX52 tires. The rear wheel is also fitted with a new sprocket design that is 50 grams lighter than the old design.

All SX models are fitted with the super-strong, tapered Renthal Fatbar 827 handlebar clamped in a mount that offers adjustment to four different positions. New, softer two-compound grips are also found on the 2015 models.

Four-Strokes

2015 KTM 250 SX-F
For 2014, KTM has included a light clutch basket to the 2015 250SX-F as well as new clutch springs for a more consistent performance and durability. The clutch continues to use the Brembo hydraulic system for light operation and controllable modulation. The fuel-injected, DOHC, four-valve single on the 250 SX-F also gets new O-rings on the oil pump suction screen for increased durability.

Technical highlights of the 2015 KTM 250 SX-F include:
- Compact DOHC engine with two overhead camshafts & DLC coated followers
- Titanium valves (intake 32.5mm, exhaust 26.5mm)
- A 14,000 rpm rev ceiling
- Flow optimized ports
- A forged box-type piston for a low oscillating mass
- A crankshaft that employs a plain big end bearing for longer service intervals
- New O-rings on the oil pump suction screen for increased durability
- A multifunctional counter balance shaft, which drives the water pump and timing chain for reduced vibrations
- An electric starter as standard, a clear advantage in the heat of the battle
- A lightweight and compact CSS clutch (coil spring steel) with eight clutch plates and a wear free steel basket
- New clutch basket with a weight-saving design
- New clutch springs for more consistent behavior under stress and over time
- A lightweight five-speed gearbox for precise & easy shifting adapted for the 250 SX-F
- An engine management system that offers the user the ability to change performance characteristics or read engine data with the accessory User-Setting-Tool

2015 KTM 350 SX-F
The KTM 350 SX-F has been a popular and winning machine in the race world, winning another MX1 World Championship and also dominating the Motocross of Nations in the hands of Italian racer Antonio Cairoli. The lightweight and compact DOHC engine offers open-class power in smaller-displacement, high-revving package. Part of that is due to lightweight titanium valves and DLC-coated followers that reduce. The 350 also gets the new O-rings that increase durability on the oil pump suction screen (like the 250), and the new, lighter clutch basket with new clutch springs to complement the CSS clutch.

Technical highlights of the 2015 350 SX-F include:
- A DOHC Cylinder head with ultra lightweight titanium valves and DLC coated followers for easier power production.
- A crankshaft that employs a plain big end bearing and force-fitted bearing shells for longer service intervals
- New O-rings on the oil pump suction screen for increased durability
- A multifunctional counter balance shaft, which drives the water pump and timing chain for better simplicity and reduced vibration
- An electric starter as standard
- A CSS clutch (Coil Spring Steel) with eight clutch plates and a new steel basket that saves weight over the previous design.
- A lightweight five-speed gearbox for precise, easy shifting, adapted for the 350 SX-F
- An engine management system that offers the user the ability to change performance characteristics or read engine data with the accessory User-Setting-Tool

2015 KTM 450 SX-F
The KTM 450 SX-F is the bike used by the Red Bull KTM factory race team in the premier Lucas Oil AMA Pro Motocross Championship class, racking up a perfect four-of-four win total so far this season, thanks to Ryan Dungey and Ken Roczen. The 450 SX-F uses a different valve train design than the 250 or 350, with a compact SOHC engine that is tuned to deliver explosive but controllable power.

Technical highlights of the 2015 KTM 450 SX-f include:
- A compact 60 hp engine with a single overhead camshaft and the latest electronic fuel injection, which offers class-leading performance
- The single overhead camshaft controls four ultra-lightweight titanium valves via extremely rigid rocker arms, which are DLC coated on the intake side
- A rev ceiling of 11,500 rpm
- A three-layer head gasket for durability under the most extreme conditions
- Bore of 95.0mm with a lightweight box-in-box type piston for low engine vibrations
- A crankshaft that employs a plain big end bearing and force-fitted bearing shells for longer service intervals
- A side mounted counter balance shaft that also drives the water pump
- Electric starter as standard
- A DDS clutch with Brembo hydraulic system
- A lightweight five-speed gearbox for effortless shifting
- New O-rings on the oil pump suction screen for increased durability
- Engine management system for a spontaneous throttle response & possibility to change characteristics or read engine data with the available to purchase User-Setting-Tool

Next Page... 2015 KTM SX Models Announced