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setting sag on a ktm

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I went from years of riding yamahas to a 07 KTM 250sxf. Do you set the sag height the same distance on the KTM compared to bikes with a linkage?

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You don't set race sag on a KTM. You set the static sag. On your bike thats 33mm. You then get kitted up and CHECK your race sag. It should be between 105mm and 115mm. If its less than 105 you need a softer rear spring. If its greater than 115 you need a stiffer spring. If its greater than 127 you will need to go 2 spring rates stiffer and 1 stiffer on the front.

DO NOT set your race sag. If your static is less than 33mm you will start topping out the shock causing damage.

Spring rates and sag settings make an amazing difference to a KTM. If the rear spring is soft it will kick you in the butt over medium size braking bumps. If its to hard it won't track well and feel harsh.

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I went from years of riding yamahas to a 07 KTM 250sxf. Do you set the sag height the same distance on the KTM compared to bikes with a linkage?

No, you don't. We call the method to set sag and spring rate on a KTM the "GOLDEN RULE of SAG". Using this method you can pick the correct spring rate for you and your bike. KTMs due to the non linkage setup like a lot of static sag to get the plushest ride. MX you should lean toward the lower numbers.

On a KTM you do start with static sag. You want 40-45mm of static sag . Once this is set you sit on the bike to get rider sag. You should have about 115mm (+ - 5mm). If you have more than 120mm you need a stiffer spring. If less than 110 mm you need a lighter spring. You should never have more than 10mm of preload on the spring. 2-6mm are best. Rule of thumb on ANY rear suspension is that 1/3 of the available travel should be rider sag. A KTM has 13.2" or 335mm of rear wheel travel. 1/3 of that is about 114mm .

Good Luck,

DR

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does the golden rule of sag apply only to 03 and 04 models? that seems to be what I keep reading. I have a 2005 200exc and the manual specifies 35mm of static. It is unclear to me if the golden rule is for the earlier models only, or if that is supposed to apply to ALL years. The Ktmtalk forums describe the golden rule to apply only to 03 and 04 models. Please clarify...

I know that small changes make a huge difference with the PDS, so changing the static form the manual specified 35 to 40 -45 seems like a BIG change...

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Same question here - does the "Golden Rule" apply to an '07 400 XCW?

Thanks,

Waxy

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does the "Golden Rule" apply to an '07

not exactly.

05-07 shocks are a bit different than the 03-04 which have a topout spring built into the shock.

Therefore you need to run about 5mm less static sag for 05-07 shocks.

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You should never have more than 10mm of preload on the spring. 2-6mm are best.

DR

If that is the case and ALL similar KTMs will weigh the same (sprung weight) then won't everyone need the same spring to get the STATIC setting right? No matter how much I weigh, the static sag won't change.

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If that is the case and ALL similar KTMs will weigh the same (sprung weight) then won't everyone need the same spring to get the STATIC setting right? No matter how much I weigh, the static sag won't change.

EXACTLY! That is why I do it bass-ackwards...set the static to X and measure the rider sag. If the rider sag is excessive obviously the spring is too soft and visa-versa. I use 40mm as my starting point. then go a turn or two either way to see what steers to suit. Also find the 05-07 doesn't need as much sag as the older models. 100-115 with most in the 105-110 area. :excuseme:

You would have to be using a 6.6, or maybe even softer, on a 4-stroke, to NEED 10mm of preload to achieve 45mm static! I would like to examine Vinnie's tape measure as something doesn't jive with mine?

If you are trying to get 30mm static then YES you would need stiffer rates. Right now I have an 8.0 on a 03 450 EXC and I weigh 180 w/o gear. Vinnie would have me on a 9.2 minimum and probably 9.6? :applause:

The whole Golden Rule deal has taken on a life of it's own. It was related to the 03-04 shock. Vinnie has made it apply to everything that doesn't have a linkage. WRONG! The problem with the 03-04 shock was the top-out spring. Made it nearly impossoble to measure preload as the shock got longer as you tightened the spring due to the T/O spring compressing. The 03-04 shock was too long which "required" excessive static sag to keep the seat from knocking you over the bars.

There are better ways to fix the problem but they aren't "Vinnie approved"...

:p :p

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but they aren't "Vinnie approved"...

mustn't be a disadvantage :applause:

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