Best tyre pressures?

[$CENSLS1$]

Hey people,
I was hoping someone could give me some good advice on the best tyre pressures I should be running on my KLX250?I currently have knobbies on the factory 21" front and 18" rear and mainly use the bike on the road (for now) I was wondering if someone with experience could give me the numbers I am looking for?

Thanks
Garry

[Nathan]

My DR650 manual recommends 22psi front/25psi rear. You'll probably be in the ballpark using those numbers. Maybe try a bit lower since the KLX250 is a lighter bike.

Also consider ditching the knobbies and getting some dual sport tyres if you're mainly doing road work. They will last a lot longer and be much safer. You'll also have the knobbies in the garage for when you want to go back to the dirt.

[Disco Dan]

Bear in mind the pressure changes between warm/cold rubber....

I have found a 2-3 psi drop in either tyre to create a noticable effect on handling on my bike... you may need to experiment a little..

[What?]

Start with what the manufacturer recommends (cold pressures). Then you might want to experiment - try reducing or increasing the pressure in one tyre by 2 psi and see what happens. Then try the same with the other tyre. Then both, then shift the pressures the other way. Remember to alter the pressures when the tyres are cold. This means you will probably only get two tests per day, so keep a notebook to record your thoughts on what the different pressures did to the handling.
Don't be tempted to make big changes - Like Disco Dan says, 2 psi will make a noticable difference to how the bike steers and brakes.

[Motu]

With a bike as light as the KLX250 I don't think you'll notice tyre pressures much.What sort of tyres do you run? Some tyres have very stiff sidewalls and you won't know lower pressures at all,some tyres are soft in the sidewall and these will flex more.I'd run 15 to 18 psi on the road,some tyres could handle 12psi no problem,some will need 25psi on the rear.

[Ruralman]

With a bike as light as the KLX250 I don't think you'll notice tyre pressures much.What sort of tyres do you run? Some tyres have very stiff sidewalls and you won't know lower pressures at all,some tyres are soft in the sidewall and these will flex more.I'd run 15 to 18 psi on the road,some tyres could handle 12psi no problem,some will need 25psi on the rear.

DEfinitely agree - I have a mate who rides a KLE400, he's not very big or heavy and runs about 12psi in both the front and the rear. We checked the pressures one day on a ride (mostly on the seal) and banged them up to the 30psi I run on the transalp. He did notice a change in the handling, faster response but also felt every bump a lot more. When we did some gravel miles later in the day it didn't take long before he was letting a lot of air back out again.
As you can see there's a big range - depends on the many factors people here have already described. As a rule you run higher pressures for sealed roads especially with lots of hard cornering, and very much lower for off road when muddy etc with somewhere in between for gravel. On my dirt bike I also alter pressures a lot depending on the surface with a high pressure hard tyre in hard rocky or dry conditions and the opposite when soft and muddy.
One thing to bear in mind though is making sure you have good rimlocks if running low pressures - otherwise the tyre can spin on the rim and rip the valve stem out.

[warewolf]

The DR-Z250 is a similar beast. Manufacturer recommended pressures were 22psi FR & RR.

With pure street tyres I ran 20-22 FR & 25 RR, it seemed to handle & wear best at that. Note that with those tyres on I was typically running above 100km/h a lot and cornering, ah, "enthusiastically".

With adventure tyres, I ran 16-18 FR & 18 RR. Any more and they really didn't work in gravel and bounced off every bump. Without rimlocks I'd hesitate to go lower. In the forest I run 11.5 FR and 12-13 RR with rimlocks and NHS tyres, but I wouldn't go that low on road (yes that is a .5 psi, and yes that .5 made a difference as it is nearly 5%).


To find out what works for you: Start with too-high pressure, for dual-sport work probably the manufacturer's recommendation. Ride the bike, if not working so good drop the pressure a little with a quick press of the valve, repeat until you are happy. Don't worry that the tyre is warm or what the psi number is. Just get happy with the bike doing it's thing at the time. After the ride, when the tyre is cold (next morning), measure & record your cold psi and the conditions you were riding in. Job

Repeat the above for different conditions or if you change tyres.