KTM announced their new 2016.5 450 SX-F and 250 SX-F Factory Editions in December 2015 and we have been chomping at the bit to try them out. We took delivery of them today and immediately wanted to give you a snippet of what all the fuss is about. Although most of the changes to the 450 and 250 KTM Factory Editions are minor from the current standard 2016 models there is one big change on both of the FE’s. WP’s 48mm AER fork. Yes, that’s an air fork on both models! Say goodbye to the WP 4CS spring fork and say hello to the new normal that KTM will be rolling out on all SX-F models, come 2017. Other changes to the 2016.5 FEs include the Akrapovic titanium slip-on muffler (450 only), FMF titanium slip-on muffler (250 only), ODI lock on grips, color anodized triple clamps, pleated seat cover, Red Bull team graphics (450 only), Troy Lee Designs team graphics (250 only), an orange frame, and D.I.D. Rims.
The 48mm WP AER air fork is a separate function leg design, meaning one leg contains the air spring and the other leg handles the damping duties. This design means the AER fork cannot go totally flat while riding even if a fork seal happens to leak or blow out. Take note however that there is an outer air chamber (on the air fork leg side) that WP recommends to leave at atmospheric (0 psi) pressure and that can be bled if pressure builds up. On top of the damping side of the fork leg there is also a bleed screw that you can bleed the air out just like a standard spring fork. We were told by KTM R&D that they usually bleed the damping side of the fork every ride or so. The outer atmospheric chamber on the air spring side hardly ever needs to be bled however, but it doesn’t hurt to check every five or six rides. KTM R&D also told us that the stock air pressure in both bikes is 10.8 bars or 157 psi. This is a good place to start when getting on either bike for the first time.
Our initial impression of both machines started at Competitive Edge MX Park in Hesperia, California. The track was disked up really well and by the time we ended our day, it was dried out and choppy. A perfect blend of chop, deep ruts, and some steep jump faces to start our impression of the FEs. We came away noticing that the 250 and 450 FE engine characters pretty much mimicked the 2016 standard KTMs that we have been riding for quite some time. The Akrapovic slip on muffler on the 450 FE was really quiet and delivered a smooth roll on power delivery that was very deceiving. To the ear it almost makes the 450 FE feel like you are going slow, but to the throttle hand it is anything but. Getting out of and inside corner and getting over a technical triple jump revealed that the KTM 450 FE was very fast, but very controllable. The 450’s top end and over-rev (just like the ‘16 model) is downright impressive. It revs out similarly to a 250F and second gear can be pulled out of a corner farther than any other 450 out there. The KTM 250 SX-F FE engine stills feels “empty” on bottom compared to the YZ250F. It takes more work by the rider to get out of a corner and I feel this engine is designed for an aggressive type of rider. Once you are in the upper rpm range this bike pulls farther than all its competitors (just like the ‘16 model).
Now to what we have all been waiting for…. Is the 48mm WP AER fork any good? Initial impression says that it is GOOD (for an air fork). I have ridden several sets of air forks in the past few years and I can say that the WP AER fork actually has more comfort through the stroke than the Showa and KYB production air forks. What sets it apart is on the very top of the stroke, the WP fork feels supple (almost plush like) and actually moves on acceleration bumps (this action takes place when the fork is barely hitting the top of the acceleration bumps). Yes, we can get the KYB and Showa air forks to feel that way as well on the track, but then we usually run into a very harsh feeling mid stroke and lose some damping feeling, especially on big slap down landings. The WP AER fork (on both models) has a less harsh mid stroke feeling and holds up well on big hits. Another positive for the AER fork is that it gives ample front-end traction. With other air forks it takes a lot of set up to get to where the rider can be comfortable steering with the front end. With the WP air fork (on both models), dropping the air pressure from 157 psi to 152 psi and increasing the compression damping helped give both machines more front-end traction through corners, still leaving it with enough hold up on jump faces. Doing this didn’t give either bike a diving sensation on de-cel or an unbalanced feeling (which is rare with air forks). When arriving at this comfortable fork setting, we did have to slow the rear shock rebound down a few clicks and increase high-speed compression (on both machines). One other thing that is worth mentioning is the Selle Dalla Valle pleated gripper seat cover. Either you should invest in some really good chamois underwear or buy a lot of Bag Balm, because this thing will eat your butt up quick. It does its job on the track, but does a number on your rear.
At the end of our first day of testing with the 2016.5 KTM 450/250 Factory Editions, we didn’t come away impressed yet (we will test at more tracks to see if we can use that word), but more hopeful. Hopeful that there is an air fork that can give a rider comfort, along with enough front end traction, that he or she will not have to change up their riding styles when hopping on an air fork equipped machine. Can KTM and WP achieve such a thing? We will find out and continue testing both machines at several different tracks and break everything down in more detail soon. Check back to dirtrider.com for more decisive information on both 2016.5 250 SX-F and 450 SX-F KTM Factory Editions.