The KTM 4CS fork thread...

anderson750

I'm working on it Rose
Location
Price, Utah
I have no personal experience with them, but they seem to have some major issues. Sometimes simpler is better. I cant wait to get my suspension back this weekend and test it out.
 

Vonski

nothing to see here...
Location
Payson, Utah
I haven't ridden in the desert yet since Brad worked mine over, so i'll be testing this weekend too. Sam sent the forks off his new husky to zip ty and they came back worse. Kreft has got them now.
 

Vonski

nothing to see here...
Location
Payson, Utah
Sign me up for the support group, just ordered a 2015 FE501. :)

Cool! You'll have to see what your own first impressions are. My bike is a totally different animal all together in comparison to that Husky, but I've been pleased with mine so far after having Brad @ Notch Peak revalve them. His goal was to pretty much move as much fluid through the valves as possible (much more than stock), then any slowing down of the action is done by way of the clickers. Way different now, in a good way...
 

rockreligious

NoEcoNaziAmmo
Location
Ephraim
Cool! You'll have to see what your own first impressions are. My bike is a totally different animal all together in comparison to that Husky, but I've been pleased with mine so far after having Brad @ Notch Peak revalve them. His goal was to pretty much move as much fluid through the valves as possible (much more than stock), then any slowing down of the action is done by way of the clickers. Way different now, in a good way...

So to achieve this theory, is it done with lighter springs, therefore more movement, then valved down with clickers?
 

Vonski

nothing to see here...
Location
Payson, Utah
So to achieve this theory, is it done with lighter springs, therefore more movement, then valved down with clickers?

Without going into too much detail (and because I don't fully understand the inner-workings of this 4 chamber design), its appears to be the opposite of what you're saying James. After trying lighter rates (as I'm under the target weight for a 300) and then still being super stiff in the initial stroke, Brad used the stock springs and revalved from there. The theory was to run a slightly heavier spring to resist bottoming on hard hits, but move more fluid through the valves allowing them to move more freely. Instead of having clickers turned back (starting from all the way in) around your typical teens or 20s, they work best between 5 to 10 is all.

Same rule of thought was applied to the shock. The only issue I've found is the stock spring rate. When on a stand and at full extension, I have the adjuster all the way up so its not totally loose, but no preload. This is the only way I can get my sag close enough to correct. I do have a 5.2 (next one down), and my sag would then be dead on, but then I may start to bottom it out in deep whoops. I dunno, I'm still testing it out.

Now, here's what happened before taking it to Brad... Prior to the Chimney Rock race, I didn't have time to have them revalved, so I figured that the next best thing would be to install the correct rates for my weight (hoping this would at least make them tolerable). A buddy of mine is a KTM tech and due to lack of time time, I had him order the springs and throw them in for me. Well, Race Tech sent him '13 fork springs which are longer than those used in the 4CS, but this wasn't caught during install. This took the typical stiff initial stroke that everyone complains about and made it even worse. After the race, I didn't know what to think and was pissed. I was ready to sell the bike with less that 30 hours on it.

Going back a little futher, I had Stillwell do the suspension on my old KTM and ultimately found out that one of his guys accidently installed .50s instead of .44s, so I've had some bad luck even before this.
 

rockreligious

NoEcoNaziAmmo
Location
Ephraim
It sounds like we both have similiar issues trying to figure out and/or have suspension people figure out all new types of suspensions, but our individual needs are completely different, Im Taller and heavier than the average rider. looks like your at least getting closer. Im more confused the more I tune, and nervous to spend a bunch of money at the suspension shop until they have a a chance to work on them more.
 

Gravy

Ant Anstead of Dirtbikes
Supporting Member
Meanwhile the only (ha) thing my Yamaha consistently does best is suspension.
Whodathunk refining the same design for 10 years would work better than changing willy nilly from weird non single rate pds then to linkage and bladders then 4 chamber stuff or air forks? :rofl:
Now if I could just find a bike that starts easily...
 

Cascadia

Undecided
Location
Orem, Utah
My bike feels like butter compared to your bike. Imo. I've only ridden it once but that was enough for me. Yamaha can't come up with a new design that works. That's why they have the same bike for the last 10 years. Wait...wasn't it you that said your next bike will be a husky 300? Oh ya, it was. Doesn't matter if your suspension works if your bike doesn't. ;)
 

anderson750

I'm working on it Rose
Location
Price, Utah
Meanwhile the only (ha) thing my Yamaha consistently does best is suspension.
Whodathunk refining the same design for 10 years would work better than changing willy nilly from weird non single rate pds then to linkage and bladders then 4 chamber stuff or air forks? :rofl:
Now if I could just find a bike that starts easily...

My bike feels like butter compared to your bike. Imo. I've only ridden it once but that was enough for me. Yamaha can't come up with a new design that works. That's why they have the same bike for the last 10 years. Wait...wasn't it you that said your next bike will be a husky 300? Oh ya, it was. Doesn't matter if your suspension works if your bike doesn't. ;)

:shawn::amy::tara::greg:
 

Gravy

Ant Anstead of Dirtbikes
Supporting Member
The only time you've ridden my bike was when the suspension was setup for a 280lb rider. I didn't like that either :rofl:
It's well established that the KYB SSS suspension is the best out of the box of any of the big 4.

The 4CS stuff and air forks have a big learning curve for the tuners.
Air Forks in particular need constant attention there is no set and forget (ask James).
In my latest MX mag I saw no fewer than 5 ads for companies that offer service to convert new air forks to springs or supposedly make the 4CS stuff work.

Your right, mechanical issues suck. I sure wish I had 8 or 9k to buy a brand new bike and another 2 or 3k to do aftermarket to it.
 

anderson750

I'm working on it Rose
Location
Price, Utah
When I talked to Pete (NOST Suspension) today, he told me he spent the whole weekend doing R&D on the '13-14' Kawasaki air fork with his N10Z valves. Maybe there is some hope for James in the future.
 

rockreligious

NoEcoNaziAmmo
Location
Ephraim
When I talked to Pete (NOST Suspension) today, he told me he spent the whole weekend doing R&D on the '13-14' Kawasaki air fork with his N10Z valves. Maybe there is some hope for James in the future.

I hope so, My 2015 is different than the 13-14 kawi with the triple air chamber, they can use my bike to R&D with, Im almost ready to pull the trigger on finding some 2012 old school sprung suspension and having it set up for me if its the correct diameter.
 
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