INNTECK KYB Fork Springs for YAMAHA, HUSQVARNA, BETA and GAS GAS 2006-2022

The INNTECK KYB pair of fork springs is designed for HUSQVARNA CR 125, TC 250, TC 449, TC 450, TXC 250, TXC 449, TXC 450, TXC 510, TXC 511, WR 125, BETA RR 125, RR 250, RR 300, RR 350, RR 390, RR 430, RR 480, YAMAHA WRF 450, YZ 125, YZ 250, YZF 250, YZF 450 and GAS GAS EC 300 from 2006 to 2022. Fork springs carry the weight of the bike and rider at the front. Their spring rate must match your riding weight with gear: too soft, and the fork dives under braking and bottoms out; too stiff, and it does not sink in enough and the front end bounces.

Specifications

• Brand: INNTECK
• Manufacturer part numbers: QS2936, QS2938, QS2940, QS2942, QS2944, QS2946, QS2948, QS2950, QS2952
• Diameter: 43.8 mm, length: 455 mm
• Sold as a pair (one spring per fork leg)
• Available versions: 3.6 N/mm: ref. QS2936; 3.8 N/mm: ref. QS2938; 4 N/mm: ref. QS2940; 4.2 N/mm: ref. QS2942; 4.4 N/mm: ref. QS2944; 4.6 N/mm: ref. QS2946; 4.8 N/mm: ref. QS2948; 5 N/mm: ref. QS2950; 5.2 N/mm: ref. QS2952

Choosing the right spring rate

Start from the original spring rate (see the bike's manual) and adjust for your riding weight with gear: heavier than the standard rider, go up one step; lighter, go down one step. In enduro, people often choose something a little softer than in motocross for extra comfort.

When to replace it?

• The fork bottoms out often or dives hard under braking: springs too soft for you.
• The front end sits high, bounces and the bike understeers: springs too stiff.
• You weigh clearly more or less than the standard rider the manufacturer designed for.
• Springs sagged after many hours: the fork sits lower in its travel than it did originally.

Spring rate is given in N/mm. Manufacturers also quote it in kg/mm: 1 kg/mm is about 9.81 N/mm (0.46 kg/mm ≈ 4.5 N/mm). Check the type and diameter of your fork: the spring must have the right length and diameter.

Fitting tips

1. Note your settings and the height of the tubes in the clamps, then remove the fork.
2. Open each leg following the manual for your fork and replace the spring, reusing the original washers and spacers.
3. Reset the fork oil level to the height given in the manual: it affects the end of the stroke.
4. Refit the fork and tighten the clamps to the specified torque, then check the front rider sag.

Spare parts and items to plan

• Fork oil : LIQUI MOLY 10W 500 ml
• Fork oil seals : ATHENA · SKF

Frequently asked questions

Do I have to change both springs?
Yes, always as a pair, with the same spring rate on both sides, except on forks with a single spring.

Are springs enough to transform the fork?
They put the fork back at the right height for your weight. The damping is then adjusted with the compression and rebound clickers.

Compatibility

Check the exact model and year of your bike in the list below before ordering.

Fits:
BETA RR 125 2022
BETA RR 125 2021
BETA RR 125 2020
BETA RR 125 2019
BETA RR 125 2018
BETA RR 250 2022
BETA RR 250 2021
BETA RR 250 2020
BETA RR 300 2022
BETA RR 300 2021
BETA RR 300 2020
BETA RR 350 2022
BETA RR 350 2021
BETA RR 350 2020
BETA RR 390 2022
BETA RR 390 2021
BETA RR 390 2020
BETA RR 430 2022
BETA RR 430 2021
BETA RR 430 2020
BETA RR 480 2022
BETA RR 480 2021
BETA RR 480 2020
GAS GAS EC 300 2020
GAS GAS EC 300 2019
GAS GAS EC 300 2018
HUSQVARNA CR 125 2013
HUSQVARNA CR 125 2012
HUSQVARNA CR 125 2011
HUSQVARNA CR 125 2010
HUSQVARNA TC 250 2013
HUSQVARNA TC 250 2012
HUSQVARNA TC 250 2011
HUSQVARNA TC 250 2010
HUSQVARNA TC 449 2013
HUSQVARNA TC 449 2012
HUSQVARNA TC 449 2011
HUSQVARNA TC 450 2010
HUSQVARNA TXC 250 2013
HUSQVARNA TXC 250 2012
HUSQVARNA TXC 250 2011
HUSQVARNA TXC 250 2010
HUSQVARNA TXC 449 2013
HUSQVARNA TXC 449 2012
HUSQVARNA TXC 449 2011
HUSQVARNA TXC 450 2010
HUSQVARNA TXC 510 2010
HUSQVARNA TXC 511 2013
HUSQVARNA TXC 511 2012
HUSQVARNA TXC 511 2011
HUSQVARNA WR 125 2013
HUSQVARNA WR 125 2012
HUSQVARNA WR 125 2011
YAMAHA WRF 450 2015
YAMAHA WRF 450 2014
YAMAHA WRF 450 2013
YAMAHA WRF 450 2012
YAMAHA YZ 125 2021
YAMAHA YZ 125 2020
YAMAHA YZ 125 2019
YAMAHA YZ 125 2018
YAMAHA YZ 125 2017
YAMAHA YZ 125 2016
YAMAHA YZ 125 2015
YAMAHA YZ 125 2014
YAMAHA YZ 125 2013
YAMAHA YZ 125 2012
YAMAHA YZ 125 2011
YAMAHA YZ 125 2010
YAMAHA YZ 125 2009
YAMAHA YZ 125 2008
YAMAHA YZ 125 2007
YAMAHA YZ 125 2006
YAMAHA YZ 250 2021
YAMAHA YZ 250 2020
YAMAHA YZ 250 2019
YAMAHA YZ 250 2018
YAMAHA YZ 250 2017
YAMAHA YZ 250 2016
YAMAHA YZ 250 2015
YAMAHA YZ 250 2014
YAMAHA YZ 250 2013
YAMAHA YZ 250 2012
YAMAHA YZ 250 2011
YAMAHA YZ 250 2010
YAMAHA YZ 250 2009
YAMAHA YZ 250 2008
YAMAHA YZ 250 2007
YAMAHA YZ 250 2006
YAMAHA YZF 250 2013
YAMAHA YZF 250 2012
YAMAHA YZF 250 2011
YAMAHA YZF 250 2010
YAMAHA YZF 250 2009
YAMAHA YZF 250 2008
YAMAHA YZF 250 2007
YAMAHA YZF 250 2006
YAMAHA YZF 450 2009
YAMAHA YZF 450 2008
YAMAHA YZF 450 2007
YAMAHA YZF 450 2006