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2017 KTM 85 SX spring rate

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So my son just moved up to the 85 class and we purchased a used KTM 85sx. We the suspension service by Powerband Racing at ClubMX in Chesterfield, SC. My son weighs 77lbs/35kgs, the suspension valving was left stock/factory, the fork springs were changed from stock (3.4n/mm) to .27kg and rear kept stock (35-215). Do these numbers sound correct because according to the manual and sag measurements we’ve taken the rear spring needs to be softer?

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So my son just moved up to the 85 class and we purchased a used KTM 85sx. We the suspension service by Powerband Racing at ClubMX in Chesterfield, SC. My son weighs 77lbs/35kgs, the suspension valving was left stock/factory, the fork springs were changed from stock (3.4n/mm) to .27kg and rear kept stock (35-215). Do these numbers sound correct because according to the manual and sag measurements we’ve taken the rear spring needs to be softer?



85s PDS work well with a progressive spring
Listed below is a racetech chart IMG_0997.JPG
The P10 is going to be the best spring.
The setting list recommends if you calculate an initial rate of less than 20N/mm to get the “ideal” sag values.
IMG_0998.JPG
Eg. 55kg = 40N/mm 45kg=30N/mm 35kg=20N/mm

Adjust the sag values to the best compromise . It is far more important to get the installed spring preload with at least 4mm + preload than to chase 100mm of rider sag!
If you end up with 85-90 just slide the forks down to adjust the chassis.
Personally i’d run 0.30N/mm (0.29kg/mm) fork springs for that rider weight

Good luck

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You need a softer rear spring

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Thanks for the wealth of information, where can I find the fork and shock setting list online?


ktmshop.se

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