I have been working with the XACT AER48 air on a 2024 SXF for a year. Looking for more comfort than what the stock valving can provide. My major complaint is the forks but I need to address shock valving as well. Although preferrable a full spring conversion is out of my price range.
Between the Race Tech single side spring conversion or the JBI DIY kit which would be the better choice? I would be willing to retain the air if the JBI kit is a big improvement over stock. Also with the JBI kit, I can do the rear suspension DIY kit at the same time and be less than the Race Tech conversion with gold valves on the forks. Not sure the Race Tech conversion would be advantageous for my ability and if I am going to do a spring, am I just better off doing a full conversion.
Wondering if anyone has experience running both the JBI kit as well as a single side spring on these bikes. I am middle aged c class vet. 225 lbs in street clothes. A spring would be setup would be welcomed for convenience but not sure if the comfort would match what I hear JBI is capable of with their DIY kit. At my skill I might not appreciate the nuances between revalved air vs single side spring. At the end of the day I just want a more fluid and plusher feel through the entire travel while maintaining bottoming resistence.
There's a few things to think about here..
The JBI kit is good. I did not find that I could gel with the feel of air forks on my XACT equipped gasgas. It did make a big difference in the feel category but ultimately i found the bike to be too harsh and lacking the ability to perform in the top of the stroke (flat corners, corner entry, small bump absorption).
I then purchased WP6500's and had them valved for moto and was not crazy about them either (not JBI setup).
I cant comment on how single sided conversions feel. I will say that I believe racetech has great setups for most bikes. I have used them multiple times in a row in my last bikes and been very happy. Their customer support and service is great. If you're in california then you're even better off.
Finally, my dislike for SFF setups is because deep in the stroke, you're looking at ~500+ LBf being exerted on the clamps and that is not distributed to the other side. Probably irrelevant but as a fellow 200 pounder I think of things like that (hey @Luxon MX plz double check my work it's been a while since i exercised my engineering degree).
JBI tons of R&D, he rides a ktm personally
With forks that are not symmetric, e.g., spring in one side, damping in the other, you're going to get a load imbalance left to right in various situations. How much will depend on the fork speed and position. Damping forces can be really high too, so for a high speed movement, damping may even be larger than the spring force. Of course if you press the forks down slow, then the spring force will dominate. Regardless, a force imbalance between the legs is a bad thing and will bind up the forks to some extent.
Where are you most lacking comfort and/or confidence?
IME, the spring forks are better for corner feel and consistency. But, the later gen air forks can be pretty good when setup right.
What air pressure, clicker settings (front and rear), and rear spring are you running?
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Just a spring conversion alone isn't going to make a huge difference in general feel, certainly not worth the $600 it costs but if you do a gold valve kit with it you'll have a better package for not much more money. This is the exact setup I have on my 2021 FX350 and I quite enjoy it.
I'm currently running a set of MX-Tech Raven cartridges in my 2023 300XC and they are the best forks I've ever ridden, I did get a killer deal on them but they are amazing. That being said if you are paying retail prices the Racetech setup is $1000 less than the Ravens and I think they perform really well.
I have heard a lot of good things about the JBI kit but I do not have any experience with them.
Dialed mfg adapters and newer sss forks will be the best bang for your buck. After reselling the upper and lowers, you might be in $500-600. Most yz450 forks will have .51kg springs which should be good for 200lbs. I’m running 22 450 cartridges with slight valving changes and it’s better than the cone valve, 6500, and diy aer kit I’ve ran on the bike. 23 350sxf. Just my two cents
I have the RT setup, and have praised it quite a bit here. I'm 6'4 and 220-230 when I'm healthy, for reference (190 right now). The RT spring conversion and gold valves improved my riding tenfold. It's softer over the rough choppy stuff, has better bottoming resistance, and turns night and day better. I used to wash out my front end nearly every time I rode and I almost never do now, I have way more front end feel. With the air forks I could never get the forks to be soft enough to be comfortable on a rough track, while stiff enough to keep from bottoming out. It was also extremely unpredictable if I bounced coming down on a big landing. I'm willing to admit this could all be placebo, but I really enjoy my setup.
As for JBI, I haven't tried their stuff, but you'll be hard pressed to find someone that talks bad about it.
2025 engine mounts should not be overlooked if you are looking for front end comfort on that bike. Used 6500 cartridges are running under $1k from what I have seen.
What are the best clamps for working with single sided forks? I assume Luxon? Would you say better triple clamps are more important with single vs dual side dampers?
Clamps really aren't specifically designed for these non-symmetric forks. But you'd want a clamp that is well machined on the fork bores (correct size and roundness) so they grip the fork tubes well, bores that are raw aluminum (increases friction so they grip the tubes better), and a design that has the most stiffness possible vertically (I would argue you want that regardless). Our Pro clamps tick all of those boxes (and our standard clamps all but the raw aluminum bores), so you could say our clamps would be a great fit.
My luxon top line setup is really good.
I am running stock airfork on one bike and 6500 on other. Aer a bit stiffer and less comfortable, but I like the light weight is easier to wheelie over bumps
https://youtu.be/SgTQ2Izu9RU
Cost effective solution and very well liked to thousands who have gone this route.
I'll 2nd this as well like $800 -900 total done both sets on my 21's.
FWIW I was going to buy gold valves when I had my suspension set up on my 350. My suspension guy told me to save my money the stock pistons are just as good with correct valving.
I installed Gold Valves both front and rear on my bike last year and I am very happy with it. If you want to do the work yourself, you can save quite a bit of money by just doing it yourself. While I don’t disagree that the Gold Valves by themselves won’t make a big difference, buying the Gold Valve kit was the only way I could get a valve stack customized for me. If you enjoy working on your bike, you can install Gold Valves yourself and save quite a bit of money (especially if you were planning to ship your suspension somewhere to get it worked on). It was fun to build my valve stacks, but I certainly don’t know enough to build them from scratch without someone telling me what shims to put where.
That’s fair. There is some good resources for revalving on your own out there. But you need to know what your after and have time to tinker. There’s some guys in Thumpertalk that get pretty deep in the weeds with it that are willing to help.
1000%!! I chased setup with the RT single side conversion for a year and was never happy. Went with the Dialed lugs and some old YZ 250F internals and I’m happier than ever with the bike. Highly recommend, great bang for the buck.
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