1. What does PSF stand for?
A. PSF stands for Pneumatic Spring Fork. Pneumatic means that the fork is operated by air.
2. What are the main benefits of the PSF front fork?
A. There are multiple benefits, here’s just a few;
- The PSF completely simplifies front suspension tuning and allows a wide range of adjustment to be performed in just a few minutes
- Previously, changing to an optional spring required complicated disassembly. With the PSF, spring characteristics may be altered in a few minutes simply by altering the air pressure
- The overall weight of the forks has been reduced by 750 grams which means significantly reduced unsprung weight. This gives the whole front end a much quicker and more responsive feeling and increased front wheel grip
- The total friction of the front forks has been reduced by a massive 20% for overall smoother operation and vastly improved rider control
- Compared to previous conventional forks, PSF has a much wider range of adjustability and spring characteristics to suit all levels of riders and varying riding conditions
3. What is the adjustable range of air?
A. The adjustable range is 220 – 280 kPa (32 – 41 psi) with 32psi being the softest setting, 35psi being the standard setting and 42psi being the hardest setting. The PSF front forks are not designed to operate effectively outside of the manufacturers prescribed air pressure range. Refer to the Owner’s Manual.
4. What is the maximum amount of air the forks can be pressured to?
A. Damage may occur to the forks if the forks are pressurised to more than 73psi (503 kPa)
5. Can I use the air pump at the service station or my own air compressor to put air in to the forks?
A. No, with just a very short burst of air from an air compressor you could easily over inflate the fork and damage may occur to the forks if the forks are pressurised to more than 73psi (503 kPa)
6. Do I need special equipment to adjust the air pressure?
A. The genuine
7. What sort of air pump do I need to adjust the air pressure in the PSF forks?
A. You will need to obtain a commercially available air pump which has a gauge range of 0-50 psi
(0 -345 kPa) in 1 psi increments, has a long hose with air valve attachment, micro adjust button and anti-air leak design to prevent leakage when disconnecting the pump from the forks. See your authorised
8. Can I adjust the fork air pressure while the bike is on the side stand?
A. No, you will need to place the bike on a stand so that the front forks are fully extended before checking or adjusting the air pressure
9. Can I install the air valve adapter tool with the handlebar clamps in any position?
A. No, when the handle bar clamps are in the front position the air valve adapter tool can not be installed with out removing the handlebars but this only takes a few minutes to do and is still a lot easier than swapping out fork springs.
10. Can I use the air valve adaptor tool if I have fitted after market handlebars or fat bars?
A. It will depend on what position the handlebar clamps have been set to for your personal preference, you may have to remove the handlebars but this only takes a few minutes to do and is still a lot easier than swapping out fork springs
11. Can I leave the air valve adapter tool permanently in the forks after the air pressure has been adjusted?
A. No, the air valve adapter tool must be removed after air pressure adjustment and before racing/riding
12. How often should I check the PSF air pressure?
A. Checking the pressure is a part of the normal pre ride check list
13. What air pressure is equal to what spring rate?
A. 35psi (2.4 Bar) which is the standard base setting is equal to a 4.6 N/mm spring rate
- Rule of thumb is, to add or reduce air pressure by 1.5 psi (0.1 Bar) will change the spring rate by 0.1 N/mm. Refer to the Owner’s Manual.
14. Can the air pressure build up or change while riding?
A. KYB has developed the internal construction and an all new type of fork seal so that the air pressure will remain constant while riding. In fact after extensive Team Kawasaki testing with Jay Marmont, even after a rugged 40 minute Moto there was no detectable change in air pressure or front end performance
15. Does the air pressure change during summer and winter months or high and low altitudes?
A. There may be some slight pressure changes however, part of the “pre ride/race checks” include checking fork air pressures so any slight changes would be adjusted before riding.
16. Would it be better to use nitrogen instead of air?
A. There is no benefit to using nitrogen as the air pressure remains constant anyway. It would only be necessary to use Nitrogen if the fork temperature would exceed 80o C which it would never do. Using nitrogen also defeats the purpose of making any front fork adjustment a quick and easy operation
17. What would happen if my fork seal starts to leak?
A. There is virtually no difference to if your fork seal starts leaking to conventional forks. You may notice some very slight decrease in the air pressure and see a little bit of fork oil weeping. As with any conventional fork you would simply take it to your
18. What other adjustments are available on the front forks?
A. There is a rebound damping adjustment screw on the bottom of each front fork with a 20 click range and a compression damping adjustment screw at the top of each fork with a 22 click range. Refer to the Owner’s Manual.
19. Is the fork oil capacity adjustable?
A. Yes, the adjustable range of fork oil is 190 – 265mm and although a change in the fork oil capacity will not change the air spring force rate at the top of the fork travel, it has a significant effect at the bottom of it. When the oil capacity is increased the air spring force becomes more progressive and the fork action feels harder in the later stage of the fork travel.
20. Will the factory Monster Energy Kawasaki Racing team KX450F's run PSF?
A. Yes. All 2013 Monster Energy Kawasaki KX450F race bikes will feature the new PSF.
