Yacugar Fork Springs / 6.5 N/mm - 9.0 N/mm Progressive / Husqvarna Norden 901

Progressive Fork Springs have several advantages over linear fork springs for long travel forks due to their progressive resistance to compression. The stock spring rate is 6.5 N/mm. These springs start at the same rate as stock to stay compliant and responsive, but they ramp up in rate as they compress to 9.0 N/mm working with the air chamber to resist nosedive and bottoming. These features are very useful in a long travel adventure bike fork.

Recommended oil and level, one liter required:

7wt oil and 140mm air chamber for more street riding and less off road.

5wt oil and 130mm air chamber for more off road use.

Air chamber is set correctly when new oil is poured in with the springs removed and fork tubes and damper rods fully compressed (bottomed out) and oil level is set to the prescribed distance to the top of the tube. Pump cartridge rod in and out several times to remove air before final measurement. Our fork oil level tool below makes the job easier but it can also be done with a flashlight and measuring tape.