Posts
474
Joined
1/31/2021
Location
Stanwood, WA, USA
Edited Date/Time
8/7/2021 4:34pm
Hello All,
I picked up a 21 450 SX-F FE this year. Overall, it’s the best bike I’ve ever ridden, stock or modified. The only fly in the ointment for me is the stock fork setup. They aren’t terrible, and are the best air forks I’ve ridden. That said, they do exhibit two air fork hallmarks based on my experience-harshness on small chop and slap down or flat landings, and blowing through the stroke on big hits.
I’m going to ride as-is through this season, then modify them this winter when they’ll need an oil change/rebuild anyway.
Cone Valves/other A Kit are out of my price range. As a result, I see three options:
-revalve/other mods, keep the air
-revalve/spring conversion
-KYB conversion (possibly out of my price range as well).
My guess is that I’ll end up going the spring conversion route. That said, the idea of the single spring just bugs me. Not sure why, just seems like a Mickey Mouse arrangement to me.
I know there’s a couple other options (Del Saggio, MX-Tech) out there as well, but it seems like those get close to the KYB cost.
I’d like to spend the least amount possible for the best value-ie if spending a couple hundred more gets significantly better performance, I’d go that route.
So for those who have done these, what are your thoughts? For reference, I am an over-40 B/C level rider. MX only.
Thanks and my apologies for the novel, lol.
I picked up a 21 450 SX-F FE this year. Overall, it’s the best bike I’ve ever ridden, stock or modified. The only fly in the ointment for me is the stock fork setup. They aren’t terrible, and are the best air forks I’ve ridden. That said, they do exhibit two air fork hallmarks based on my experience-harshness on small chop and slap down or flat landings, and blowing through the stroke on big hits.
I’m going to ride as-is through this season, then modify them this winter when they’ll need an oil change/rebuild anyway.
Cone Valves/other A Kit are out of my price range. As a result, I see three options:
-revalve/other mods, keep the air
-revalve/spring conversion
-KYB conversion (possibly out of my price range as well).
My guess is that I’ll end up going the spring conversion route. That said, the idea of the single spring just bugs me. Not sure why, just seems like a Mickey Mouse arrangement to me.
I know there’s a couple other options (Del Saggio, MX-Tech) out there as well, but it seems like those get close to the KYB cost.
I’d like to spend the least amount possible for the best value-ie if spending a couple hundred more gets significantly better performance, I’d go that route.
So for those who have done these, what are your thoughts? For reference, I am an over-40 B/C level rider. MX only.
Thanks and my apologies for the novel, lol.
In hindsight, I learned rhe biggest issue with airforks is poor shock setup, if the shock isn't holding rhe bike up, the forks don't work as well, especially in slap downs. The big HS comp adjuster makes a significant difference, wind it in quarter turn at a time. Also, if you've come off Japanese bikes, you kinda have to relearn sag setup.... measure the spring, and then add 7mm preload, which should give 105mm sag. If you need too much preload to get a bigger spring and round up not down.
The Shop
Luxon 4-Post Bar Mounts
$189.95 - $239.95
DeCal Works Huge Plastic Inventory of UFO and Polisport kits.
I think JBI make a leaf spring kit for the AER that has great reviews. Around $200 if I recall.
He bought Cone Valves (48mm) and had them valved by FC along with his OEM shock. The shock was decent and the forks were very active and light on damping for him (225lbs 50+Expert) as well as me (160lbs 30A & 40A).
I went through the cone valves and tried shims in the mid-valve. We got them working well, but eventually decided to put the cones back in and mess around with the float / preload. The cones work well now, he likes them and runs them with the National shock from MX-Tech.
I've developed a kit that drops in any KX or YZ cartridges from a KYB 48mm AOSS or SSS fork.
Same buddy has a set of coated tubes with the larger 25mm internals from a 2020 YZ250F and 0.50kg springs.
The front end traction on that fork is better than anything I've ridden and the comfort is great.
I also have two other sets of forks out there being tested with my KYB kits:
2018 KTM 350SX-F 2018 YZ250 internals (220lbs 40+B rider) he loves them, especially on slapper landings.
2021 KTM 250SX 2021 YZ450F internals (200lbs age 26 local pro). He says the stock stuff was terrible in comparison.
KYB is the way to go in my opinion.
It improves the KTMs enough that my next new bike will probably be a GasGas or KTM 350.
There will be a less expensive solution for that available soon. The intent with that is that a fella can buy new cartridges from any Kawi or Yami dealer, Enzo or Tech-Touch and install them himself. The guy on a budget can find a set of good-used YZ or KX forks and gut them, install the kit himself. The third option is that a suspension tuner can do all the work and retail 100% of the parts with valving, springs, setup.
Aees, I’m running a 5.5 (not sure what that equates to in n-m) rear spring at the recommendation of FC (I’m 240).
Have you revalved the shock?
https://www.vitalmx.com/forums/Moto-Related,20/New-WP-XACT-Pro-6500-Car…
Like a KYB conversion, they appear to be dual spring, dual damping cartridge. Information on them seems a little sparse at the moment but it would appear these would drop right in, eliminating the need for changing the fork lugs or other mods. They also have external spring preload adjusters.
Interested to see how these do once they are out in the wild.
https://www.wp-suspension.com/procomponents/offroad/xact-pro-6500/
Pit Row
If you are right now in the middle of clickers of low speed comp (12-17), and 2.5-1.5 on hsc, just drop out 6-7 clicks on LSC to 21-23, and go in to around 0.75-1.00 on HSC.
This will make the forks feel about twice as compliant as before. LSC is pushing down the forks in the stroke way to much.
Test that, and report back.
Shock:
LSC-15
HSC-2
R-13
5.5 spring, 105mm sag
Forks:
156 psi
C-14
R-20
The shock actually feels really good, but admittedly I’ve always focused more on fork feel-as long as the shock doesn’t kick up or sideways I’ve never been super picky. That said, I do understand that even if it feels good, it could be affecting the forks.
Thanks again for all the help and advice.
Shock:
LSC-22
HSC-1.0
R-13
5.5 spring, 105mm sag
Forks:
156 psi
C-14
R-20
Most riders have too much sag therefore the balance of the bike is off by a lot. I am happy with 102 mm currently.
Make sure that you are fully geared up in ALL of your riding gear before setting sag- you will also need two helpers to set correctly, every when using an electronics sag scale. Stand up in the middle of the motorcycle with no hands on the bars when setting sag.
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