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small rider suspension nightmare


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I have a 2008 KTM 200 (PDS).

I am 5'4", 135lbs, and have short legs.

 

I race B harescrambles in New England. 

I am one the lightest riders and probably the shortest.

On the fast smooth hard pack or sandy stuff I am phenomenal, most likely the greatest of all time.

I know everybody is fast on smooth easy track... but I'm faster than that.

 

But add bumps, any bump, and suddenly I am by far the slowest guy out there. I assumed for years that I just needed more practice on hard/rocky/rooty terrain, but over and over again I see people mosey past me like its nothing while I am trying my absolute hardest to keep control.

 

Any kind of rock or root, big or small feels like a combination of riding on marbles and a bouncy house. My bike wants to go anywhere but straight as well as shooting up vertically.

Additionally to that, I cannot touch the ground at all. So any erratic movement that throws me off balance requires gymnastics to touch ground and secure myself.

 

I've had my suspension done by a reputable guys who do suspension for other racers (2 different places). I'm positive they know what they are doing.

My suspicion is that a the springs rates calculated for my bike are wrong for light riders ( I assume there is some table KTM or WP provided for selecting the right spring).

Or the that valving needs to also take my weight into consideration.

 

I have played with the clickers which helps but I am still no one near where I want to be.

My forks now are soft enough to bottom out if I hit a woop wrong (which is fine) but still don't seem to absorb small fast bumps.

The best clicker settings I ever did was virtually no compression dampening (3 clicks above 0) with light rebound dampening (12 clicks above 0). It bottomed out on anything fast but help stop the bike from launching off rocks and roots (still was not great though).

 

Another thing to note is that I have 1" taken out on both the forks and shock to make the bike lower. I know this does not help the situation as it takes away suspension travel but it does help for touching the ground. 

 

Does anyone know anything about this or had a similar experience?

Would a fork with a separate hi speed circuit help my problem?

Do the newer KTMs have better suspension?

Thanks.

 

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Your counting clicks from the wrong direction btw, always from closed its the true zero.

Short riders should be able to get away with lighter springs and valving than tall riders.

Perportionally longe wheelbase and lower center of gravity requires less pitch controll for braking and acceleration.

What free and race sag?

what spring rates?

If the springs are right 

You might have too much low speed damping.

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High speed damping is the issue. I did a set of forks on a 300xcw same year as yours. Are you up for revalving it yourself? Stock midvalve float was .6 on the 300, I changed it to 1.0 and the rider is very happy with rock and root compliance. On these forks you just remove the 2 smallest shims on the midvalve compression stack. 

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I did not do the suspension work myself and do not know the spring rates.

The springs were selected for my weight.

 

I have around 90mm of race sag. 

I was told with the 1" shortened shock that the sag would be 1" (25.4mm) less than it would normal be.

90mm + 25.4mm = 115.4mm.

 

The forks seem to problem. These forks do not have hi speed dampening. 

 

Regarding the clickers,

I was told to keep it within +/-8 of what the original settings were post rework. Exceeding that would bypass the valving and blow through the stroke.

I have  gone 8 clicks softer on the compression, and 2 or 3 clicks softer on the rebound. 

 

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If you haven't already had a good discussion with your last tuner I would suggest that first. If he is known to be good with KTMs and you still have trust in him I would ask him for another shot after sharing all your info with him.  Great post also! 🤣

Edited by AngieRider
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5 hours ago, 2strokezuke said:

I was told with the 1" shortened shock that the sag would be 1" (25.4mm) less than it would normal be.

90mm + 25.4mm = 115.4mm.

 

No, that's wrong. It's a percentage thing. If you lose 1" off 12" travel (guessing) that's roughly 8.8%. So you should lose 8.8% of your sag. Which if it was 115mm should now be approx 105mm.

Sag should always start at around 33% of your overall travel.

If they've done the same in the forks, they may have too much preload now. You need to try to measure the approx sags there too.

Edited by DEATH_INC.
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Good to know on the sag.

Right now I have the shock preload about as low as I can go I think.

I am 1 turn in on the collar from the spring being loose (with the bike raised up). 

Can I go anymore than that or is the spring to stiff for my weight?

 

As far as the forks, it does feel like there is lot of preload. They don't really compress when I get on the bike. It takes a lot force to initialize movement.

I assumed this was because of the 1" travel taken out, starting further in on the stroke.

 

As far the suspension guy, yes he did offer to take another look at and mentioned the 1" shortening as a possible cause and mention upgrading to forks that have Hi-speed.

I can not do that right now though. They are only few races and I don't have $600 laying around at the moment.

I want to figure out why this isn't working before I have it reworked again in the off season.

I've had similar results with all the suspension revaIving done (3 times now I think). So what ever is happening or not happening is going to repeat unless I figure out what is going on.

 

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On 8/2/2021 at 7:37 PM, 2strokezuke said:

On the fast smooth hard pack or sandy stuff I am phenomenal, most likely the greatest of all time.

I know everybody is fast on smooth easy track... but I'm faster than that.

 

But add bumps, any bump, and suddenly I am by far the slowest guy out there

Probably the funniest thing I'll see for the next week... 

"I'm fast on flat smooth ground, but slow as shit on rough ground" 

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7 hours ago, 2strokezuke said:

Good to know on the sag.

Right now I have the shock preload about as low as I can go I think.

I am 1 turn in on the collar from the spring being loose (with the bike raised up). 

Can I go anymore than that or is the spring to stiff for my weight?

 

As far as the forks, it does feel like there is lot of preload. They don't really compress when I get on the bike. It takes a lot force to initialize movement.

I assumed this was because of the 1" travel taken out, starting further in on the stroke.

 

As far the suspension guy, yes he did offer to take another look at and mentioned the 1" shortening as a possible cause and mention upgrading to forks that have Hi-speed.

I can not do that right now though. They are only few races and I don't have $600 laying around at the moment.

I want to figure out why this isn't working before I have it reworked again in the off season.

I've had similar results with all the suspension revaIving done (3 times now I think). So what ever is happening or not happening is going to repeat unless I figure out what is going on.

 

I think you need to look into your spring rates and preload. Your spring rates sound too stiff.

Spring rates and preload are the first things that need to be done to any suspension to get it right.

I suggest a Racetech progressive spring. I know there are some that say you can stay with a straight rate spring, but the progressive curve of PDS is very flat, the racetech spring makes the rate mimmick a linkage curve, which means it can be softer initially but won't bottom as easily as a straight rate spring. I guess if bottoming isn't an issue, like you don't jump or anything a straight spring may work ok.

This is from an early one with a factory progressive spring;

image002.gif.717ea1c19f0a94a3b7fb60565c7b5920.gif

 

You really need to find someone that understands PDS correctly to do the work, they're a little different to normal.

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On 8/4/2021 at 8:52 AM, 2strokezuke said:

Right now I have the shock preload about as low as I can go I think.

I am 1 turn in on the collar from the spring being loose (with the bike raised up). 

Can I go anymore than that or is the spring to stiff for my weight?

If you need to back off the spring preload to almost zero to achieve the recommended sag values then yes your spring is likely too stiff.

Edited by mlatour
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  • 3 weeks later...

I was on the vacation for the past 2 weeks...

 

The tuner is not close enough to see how the bike is acting. 

The rear spring is a progressive spring, but likely too stiff from what you guys said.

 

It feels like the problem is more the forks though. 

There soft enough to bottom out on whoops 15-25mph, but feels like either a solid frame or a spring board on any hard fast bump or technical rooty stuff. I just bounce everything and have no control.

 

On 8/3/2021 at 12:40 PM, jjy130 said:

High speed damping is the issue. I did a set of forks on a 300xcw same year as yours. Are you up for revalving it yourself? Stock midvalve float was .6 on the 300, I changed it to 1.0 and the rider is very happy with rock and root compliance. On these forks you just remove the 2 smallest shims on the midvalve compression stack. 

 

I was told that these forks have no hi speed dampening circuit. Is that not true?

---------------------------------

I think these are my options.

going down a fork spring size (which the turner was adamite that was not the problem)

Taking out the 1" shortening thing. (add 1 inch of fork travel)

Upgrading the forks to like KYB or something that has a hi speed adjustment.

 

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  • 4 weeks later...

I have some updates on the issue. 

 

I messed with the fork clickers, going softer 2/3 clicks at a time. 

When it got to a point it actually felt harder, I added 2 clicks (more dampening).

Then went 2 clicks softer on the rebound; the suspension woke up and was much better.

 

I tried doing the same procedure with the shock...

I went 3 clicks softer, the whole suspension felt like shit again. 

I added the 3 clicks back and called it.

 

During the race the bike was killing it in the dry parts. I was NOT bouncing off stupid rocks and roots anymore and was able to go as fast as I wanted.

But, anything thing wet or slightly muddy (which was 3/4 of the track) I did not have control. The front wheel wanted to slip out.

I would have to slow way way down and watch people mosey past like it was nothing.

 

Still had the problem of being bounced of the pegs in the technical crap.

 

I thinking the shock dampening is too soft and going to far into the stroke. 

Which is pushing the weight forward making the front unstable.

Or I might need to go softer on the shock rebound, speeding it up. I have a hard time determining when to adjust the rebound.

 

 

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