KTM 400 sx landing really harsh!

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Oct 23, 2000
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#1
I desparately need to know what to do to my 400sx before I kill myself trying to land a double with my 13 year old. Does anyone know for what weight rider the bike comes sprung for? I weigh about 210-215 with gear. When I land on most any jump it seems hard but is almost impossible for me to hang on to on really big ones. I crashed hard and bruised my thigh pretty bad today. I would ideally like it to work similar to a Yamaha or Honda suspension , is this possible? I have adjusted compression and rebound but it just doesn't seem to make that much difference. Do I need to revalve or re-spring? thanks :(
 

Jeremy Wilkey

Owner, MX-Tech
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#2
HG,
Something is wrong. What year is your KTM, and what is the service history. The bike should work decent enough stock. Can you give us more information.

Regards,
Jer
 
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#3
400sx harsh suspension

There is no service history basically, the bike is stock other than I have tried different adjustments on compression and rebound. As previously mentioned I weigh 210-215 with gear and someone mentioned that they thought the bike came sprung for a 170 # rider ,is this correct? OK I will admit I'm not as young as I use to be , 48 in september, but I still think I ride pretty good for my age. I have a buddy who is 46 and just bought a cr 250 and he has a similar history as me as for as riding goes and he looks much smoother on his landings than me. We trail ride a lot but like to practice on mx tracks too. But unless I can find a way to cure this problem soon I don't know how much longer that I can last. thanks for any help you can give me or any advice.
 

Jeremy Wilkey

Owner, MX-Tech
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#4
HG,
Thanks for the info... I caught but deleted your 01 coment. Thanks for the info.. Anyway a few more questions.. Are you bottoming? Or are you just getting slammed? The stock bike is for lets say a 180 guy but, unless your going fast I doubt it's that big a deal. The Cr is set up for a simmllar person... Anyway answer the botoming or just harsh question and we can go places..

Thanks
Jer
 
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#5
Just as a note:

My dad has a -01 380 SX which has probably close to what the 400 SX should have in terms of suspension. I'm 220 lbs and can land jumps on that thing even with the softer spring my dad likes installed. Yes it bottoms but I don't feel like it's life-threatening.
 
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#6
400sx harsh suspension

I must be bottoming but I can't find anybody that saw me to confirm it, all I no is that I tried this double at a mx track and almost lost it the first time and did lose it the second time, bruised thigh etc.,and I have ridden many different brands of dirt bikes since the early seventies but onr the old tracks we didn't have anything that resembled a double. I just figured if my buddy could handle it fine on his cr250 and I'm getting bounced off the bike that I have a problem, he also weighs about the same as me. And it does seem a little rough on the smaller stuff. I did not ride for maybe 14 years but started back 98 with a xl 600, xr 350, wr 400 before I bought this bike. The wr400 suspension seemed really good to me but I just didn't like the weight and hard starting. I like this bike but if it can never perform suspension wise as good as a Yamaha or Honda I may have to look at changing bikes again but I really would like to know if this can be fixed to my satisfaction first. thanks
 
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#7
I wouldn't give up on her yet. You're probably going to need stiffer springs and a revalve, and then you'll have a custom set-up - for the same money it would cost you to sell and re-buy. Jeremy will take care of you.

Are you sure you're clearing the doubles fully? When I first started riding I thought my suspension was way too soft and harsh but when I started fully clearing the jumps I found that it's okay.
 

HiG4s

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#8
I would be pretty confident it can be made to work for you. I know on my old KTM 250 exc, witih it's softer suspension I could jump as well or better with it than as I could on my friends Honda CR250 (I weigh 195). But after a few years off I am having trouble with my newer Husqvarna 125 motocrosser. I think part of it is I have never really gotten use to the harshness of full motocross suspension, and I really don't have the ability to push the bike to it's potential. I might be a simple as the compression is to stiff for you and/or there is not enough rebound damping and the bike is springing back up after the hit too fast to control. Try the link to the MX-Tech website and try to adjust your suspension by their directions. If that doesn't work you might want to think about having them redo your suspension. I'm still playing with the adjustments on my Husky but I may need them to redo mine. It just seems too stiff for my style.
 
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