Proper spring rate for MX-ing ‘22 KTM 300XC

You might need the next one over 4.8.  

It is my experience that once you get to the 200lbs + range, adding more spring rate is key for mx applications.   Lots of people talk about harsh forms, and for bigger riders, harsh forks can be attributed to too soft a shock setting. 

21 250sx I first tried the 4.8 much better but still lil too soft. I've been running the 5.0 for awhile and its been good. I'm 185 without gear. Novice to slower intermediate vet. Occasionally I still bottom out the 5.0 like it's a little to soft still. At 200 go minimum 5.0 I think you'd like the 5.2 more. 

I put the 4.8 on my 21 150sx and it was definitely an improvement. 

Did you guys revalve when you went to 5.0 or just increase rebound a few clicks?

thx

No just put it on and rode it

Doesn’t matter if you’re riding MX or trails. Spring the bike for your weight to get about 105mm of sag. Valving is what needs to be changed for different disciplines. 

Bingo.

OP a 4.8 will be too light, start with a 5.0, you may end needing a 5.2. 
 

sag numbers don’t lie. 

Please check your sag with gear. Should be 105mm. Free/unladen sag should be 30-40mm. Less than 30 spring is too soft, more than 40 too stiff. Think of it like this: the spring counters your body weight. The valving affects the action.

I haven’t been around KTM’s that long, got my first one in 1999 and since then the manuals have not been correct in many areas. Suspension and jetting in particular, they should just be removed those sections from the manual. 
 

And as far as why? Your sag numbers will not lie and provide the info you need to get the correct spring. I weight the same and have basically the same bike. 4.8 was too light, and 5.0 is on the cusp of being too light. 

 

also if you weight 200lbs you’re likely closer to 220 with gear on.

I am 215 naked 40+ vet. I’m not fast but like chasing my kids and will hit a mild triple to keep up (as riding reference). I thought I might try and mod my 22 300xc suspension for the track but ended up realizing that at my weight it was making it no fun off-road anymore.

300xc offroad i like a 4.8 which requires a bit more preload to get to right sag numbers but i prefer it over 5.2 that i -have- to run at the track. Even with 5.2 on the 300xc  i was almost maxed out on stock compression clickers and it made the bike really harsh everywhere but jump landings. It was horrible offroad in that config.

The XC valving is just too soft for a bigger guy on the track, though I don’t mind the stock valving on offroad at all. 4.2 is way too soft even offroad for 200lb guy IMO.

I eventually bought a track only bike and revalved it and run 164psi and a 5.2 in the rear.

Ive got a couple extra very lightly used springs in the 4.8-5.1 range i can sell ya if you want to save a few bucks once you decide what to do.

If you’re truely a beginner and just learning how to safely jump a 10 foot table then right springs and compression changes on the XC will work. Eventually you’ll be over riding it however.

https://www.instagram.com/reel/CqGjuMMOs2D/?igshid=YmMyMTA2M2Y=

My above settings let me handle this, which is about as big as I’m willing to go chasing my kids.

The race sag vs free sag spring rate test is supposedly not the best way to spring these bikes....

The information I have, set the race sag to 105mm, even this is hard since sitting position on bike cam change the sag on this linkage, so standing to set sag is best with a friend helping.

Most oem springs are 260mm, the manual calls for 7mm spring preload,  so with 105mm race sag, preloaded spring should be 253mm.  If it's less, eg 250mm, then you need too much preload and the spring is too soft.

Once you get heavier, revalve is important,  I add 2 shims to comp and 1 to rebound and then dial bike with the 17mm high speed adjuster.

Doing rhis makes the forks work a lot better since the bike holds up better

I'd go with the 48NM if I was you.  I am pretty much the same weight as you (185 dry, 200 in gear) and I am running a 45NM.. but I like to be a little lighter on the spring, higher on the sag.