2015 KTMs to receive WP 4CS Fork

In spite of initial indications from KTM that their 2015 SX and SX-F models would retain the WP 48mm closed-cartridge fork, it turns out that what we published last week about the new Katos was not entirely true. The 2015 motocross models destined for the Australian and American markets will in fact get a much-revised version of WP’s 48mm 4CS (4-Chamber System) fork. This is the fork that first appeared on KTM’s Special Edition Six-Days models a few years back, and has subsequently been fitted to Husaberg’s 2013 and 2014 enduro models, Husqvarna’s 2014 enduro models and, more recently, KTM’s Factory Edition 450SX-F (the Ryan Dungey replica that’s essentially a 2014.5 model, and was released in limited numbers late last year).

As KTM Australia’s Technical Services Manager explained to Transmoto, “The confusion over which fork the 2015 KTMs will run has come about because the SX and SX-F models will retain the closed-cartridge fork in Europe, and these were the bikes used for all the press photographs that have recently done the rounds online. The SX and SX-F models sent to Australia and the USA, however, will definitely get a 4CS fork, but it’s much more than simply a re-valved and re-sprung version of the existing 4CS fork. The 4CS fork on KTM’s new motocross range is significantly different and comes with all-new internals,” Twyerould went on to clarify.

This explains why a few switched-on suspension tuners around the country have been busying themselves with WP’s 4CS fork in recent weeks, in preparation for the new KTMs’ arrival in late July. The clarification from KTM Australia also confirms what we were thinking all along: that the upgrades found on the Factory Edition 450SX-F (such as the revised frame and linkage, upgraded suspension settings, Dunlop MX52 tyres, lighter front axle and 4CS fork) were in fact a forerunner for what would appear on KTM’s 2015 production bikes.

But it’s got to be said that KTM’s decision to fit the 4CS fork to its 2015 MX bike range is a curious one, as the 4CS was never designed as a MX-bike fork. It was designed with added stanchion flex to create the sort of supple, compliant ride suited to enduro bikes. Admittedly, the 4CS fork on the MX models has all-new internals, but from what a few suspension tuners tell us, its settings are pretty wild to make it stiff enough for MX applications. And several have suggested that it’s a backwards step for KTM’s MX range.

So, why did KTM do it? The general consensus is that it was driven by US market (as was the KTM’s decision to dump the PDS and revert to a rising-rate shock linkage on their MX range back in 2011). It’s no secret that the American mags have slammed the performance of KTM’s closed-cartridge fork in recent years, meaning that KTM needed to try another fork for 2015 before WP’s air fork hits production in 2016. At least, that’s the pundits argument.

These developments also beg the question: if the KTMs get the 4CS fork, then how is Husqvarna’s 2015 MX range going to differentiate itself from the Kato’s? As we proposed (in a speculative piece a few weeks back about the degree of design divergence we’d see from the 2015 KTMs and Husqvarnas), it’s highly likely that Husqvarna’s 2015 MX models will also get the new-generation, MX-specific 4CS fork, meaning the ‘premium-spec’ Huskys will have to find their promised design divergence elsewhere. Will they move back to a no-linkage PDS shock absorber? Just joking. Of course they won’t.

So just how will the Austrian in Swedish clothing justify its price premium for 2015? It looks like we’ll have to wait until the international launch in Sweden at the end of June to find out.