KTM Shock Piston on RMZ 250

racerfmx450

Posted 13 March 2012 - 01:57 PM

i will try a ktm Shock Piston , 50mm 3 port from a SXF 350 on the Showa shock,RMZ 250 2012.

i think the Piston will fit the Showa Shock, but i need a Baseline for the Valving.

Can anyone tell me the stroke of the KTM WP Shock, also the spring Rate.

has anyone tryed this ?

(The KTM Piston looks good to me, much less stiction on the band and cost ~ € 18,--!!!)

Thanks!

Edited by racerfmx450, 13 March 2012 - 01:58 PM.

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Posted 13 March 2012 - 02:17 PM

I was going to try it, I have the piston kindly donated by drewurm, but I have not hot around to trying it :-( try the 12 350 settings, the spring rates are almost the same, don't know the stroke

racerfmx450

Posted 13 March 2012 - 02:26 PM

Thanks Markus.

good to know the springs are the same , i can use the reb stack and tune it for my spring (5.2 N7mm)
(my rider has 65 Kg, very fast .the stock rmz spring and valving its way to stiff.)

do you have a baseline for the fork? fast and light Rider, i think i use the stock springs with 0mm preload, much softer base and stock mid and reb.
lower oillevel also..

Posted 13 March 2012 - 02:43 PM

On the shock I would run the std rebound and run the adjuster further out 16-20 to get more bleed on compression

On the fork I am the same weight and this setting works for me

06 crf base stack with 12 face shims
0.45 springs
310cc
mid std with one less face shim, 0.1mm more float due to less shim

Its a decent setting but maybe a little more taper on the mid would help on hs

karlace

Posted 13 March 2012 - 02:44 PM

I've had problems with a 2012 ktm piston wrecked the ring in 7 hrs from new, I got a piston band kit from mark at rss basically half a ring thinner energiser band and other half nylon worked well, I don't think I'm the only person to have piston ring problems with the newer ktm shocks the thinner energiser band helped reduce friction. Also I think u might be better to run a more tapered rebound stack if u run the ktm piston and stacks. If u look at the rebound stacks the ktm run they don't need as much hi speed rebound, ur Suzuki linkage is different to the ktms, I think ul need more hi speed and longer tapper, more tike the STD Suzuki stack. Just my thoughts on it. A set up is more than just a piston, valving, linkage, but all and more.

karlace

Posted 13 March 2012 - 02:47 PM

Marcus we must of been writing at same time. Lol

Posted 13 March 2012 - 02:51 PM

From daves rebound stacks it appears its hard to run too much stack stiffness on rebound, I like a decent rebound stack to make it feel planted

karlace

Posted 13 March 2012 - 02:51 PM

I done a rm250 last week and run a mid I've used on a rmz250
5x20.1
19.1
17.1
15.1
13.1
11.2
.2 of float
Had good feedback from using this stack

karlace

Posted 13 March 2012 - 02:56 PM

I have added to the tapper on a linkage ktm and not reduced shim thickness and when I put the shock in the bike it felt like the linkage had sizzed up, felt like something wrong big time. I've also only added 1 face shim and run STD highspeed and found the clickers at 17 out I want to play with the tapper more but reduce shim thickness , got to test that's bottom line.

Posted 13 March 2012 - 03:06 PM

#10

That's still a stiff mid compared to a crf, but soft compared to std rmz, makes me laugh whenmxa say the rmz comes sprung for 140lb and soft

Posted 13 March 2012 - 03:10 PM

#11

Don't forget adding hs still adds low speed, so with so few shims in the taper it will make a difference

karlace

Posted 13 March 2012 - 03:17 PM

#12

If ur talking about the crfs with 47mm Showa (2009) &older i think most of the stacks had a tapper of 1mm increments and less float so maybe with my mid and STD bv would of seemed harsh my bv was single stage with less face shims than crf and 2mm increments in the tapper. 16 clamp. Fancy trying a stack in ur rmz if I mail it to u.

karlace

Posted 13 March 2012 - 03:21 PM

#13

R u talking about ktm rebound, that's why I think the high speed stack needs narrower shims if ur gonna try to shape the tapper more.

racerfmx450

Posted 13 March 2012 - 10:45 PM

#14

thanks for the Info..

has anyone the measure of the KTM Piston?

just to play with the stacks on the shimrestakor.

Posted 14 March 2012 - 12:39 AM

#15

Sorry I was confusing you lol, yes I was talking about the mid on the showa and then I jumped to the rebound on the wp, I really want to try to fit a set of kybs to the rmz, the 450 kxf forks appear about the same size

karlace

Posted 14 March 2012 - 12:54 AM

#16

Marcus ur not using a tapered mv, have u tried and what stack and float. On ur rmz, have u a got the rmz with loads of ls reb on forks have u reduced that or how does that feel.

racerfmx450

Posted 14 March 2012 - 03:15 AM

#17

I see both has 126mm stroke on the shock and the same springrate stock.

I would like to try the SXS setting for the rmz.

Posted 14 March 2012 - 03:36 AM

#18

Hi Karl I did not ho down that road as basically I knew it works well as I have done just that on crf etc, I was looking to see if it was possible to get it working well via a different route

06 crf base with 12 face shims
Mid one less face shim 0.35 float
0.45 spring ( stiff for my 150lb)
310cc to counteract the stiff springs

Its a good fork, sits high in the stroke and takes hard hits well, I could revalve it but it wont be a kyb :-(

Posted 14 March 2012 - 03:38 AM

#19

Its got the std heavy rebound but I don't mind it, older ones felt too springy to me anyway

cardinale199

Posted 14 March 2012 - 01:45 PM

#20

i talk with a tuner here and use the ohlins piston in rmz shock for remove xring!!!

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