I'm used to running my tires at max psi so I can get both rigid travel and best fuel economy. So lets say 42 psi in the rear and 32 psi in the front.
Since I'm due for a tire change, I've been running my tires at 30 psi (front) and 32 psi (rear).
At what point is there more traction until lowering the psi actually worsens traction or travel?
I also heard lowering the air pressure for off road use helps maintain control. However, more easily to puncture tire.
I helped fix my friend Nighthawk the other day, and he said his bike used to get like 50 mpg but now its getting like 30 mpg.
I checked his tire pressure, and his front was like 19 psi, and his rear was like 20 psi. I told him he should fill them to 33 psi (recommended per tire/frame).
His mpg returned to normal.
Returning to my earlier question, I'd like to know the point where traction is best with lower psi. Definitely 20 psi is too low I think...
IT depends on condition..
If you lower your pressure, you will get more tire on the pavement, think about when a tire is flat.. More tire on the ground right.. However, you will get more lateral movement in cornering as well..
Lowering the pressure pretty drastically can give you more traction in loose dirt/sand/mud, but is not good for the street..
Pressure can effect MPG as well, but your friends example seems a little extreme.. 50 to 30 MPG.. Possible, but I would think 5MPG would be more likely..
Quote from: hootmon on March 09, 2010, 11:04:31 AM
IT depends on condition..
If you lower your pressure, you will get more tire on the pavement, think about when a tire is flat.. More tire on the ground right.. However, you will get more lateral movement in cornering as well..
Lowering the pressure pretty drastically can give you more traction in loose dirt/sand/mud, but is not good for the street..
Pressure can effect MPG as well, but your friends example seems a little extreme.. 50 to 30 MPG.. Possible, but I would think 5MPG would be more likely..
I'm going off his estimates, not exact science.
I was more looking for more or less...
If i run 30 psi...better in corners than say 36 psi.
25 psi even better in corners?
Any idea?
The lower air pressure the less handling you will have in corners as the sidewall will be softer and flex. there are trade offs to both.
I agree the mileage would be closer to 5 to 10.
Double check the PSI I am thinking it is upper 30s to mid 40s is the proper PSI.
Quote from: DG on March 09, 2010, 01:05:16 PM
The lower air pressure the less handling you will have in corners as the sidewall will be softer and flex. there are trade offs to both.
Yeah, what he said...
Look at dragsters, they have low pressure for better grip in a straight line, but a formula 1 car has rock hard tires to allow better handling...if your pressure is to low, you're going to feel the bike squirm and wander in the turns, not going to give you a good safe feeling. If you feel like you're going to get better grip lowering pressure due to worn tires, don't go too low, I wouldn't drop below 30. I run them about 38 PSI and it's rock solid in the twisties...
Off roading is another thing, when I rode enduro in Florida, we'd run about 8-10PSI to be able to run in the sugar sand that's about everywhere, if you had too much pressure, you weren't going too far without going down...
I read somewhere that the general wisdom is that you should not go below 90% of the max rated pressure, for the best combo of wear/handling.
Quote from: Magniac on March 09, 2010, 03:30:13 PM
I read somewhere that the general wisdom is that you should not go below 90% of the max rated pressure, for the best combo of wear/handling.
The instructor in the local advanced MSF course suggested 90% of the max rating. So at least these two "sources" agree. That must make it right!! :roll:
On my track bike the tire pressure slightly changes with each track and weather conditions but it is usually around 26 psi. Lowering the pressure increases traction but shortens the life span of the tire. I don't notice any squirming on the CBR but it is also a whole different setup than the Magna so I cant say at what point lowering the psi actually worsens traction or travel?
Jeff, your also running race tires correct? They have a much stiffer sidewall and are designed for the lower pressures than a street tire is. IIRC
I am running Pilot Powers and yes you are correct. The reason to run the pressure lower is to build up heat quickly to get better traction sooner but as you can imagine tire wear drops drastically. Any race that has pit stops or drag racing you will notice that when the tires are cold the drivers/riders times are slower but as the heat builds up their times get better. Another way to precondition the tires to get heat in the tires is tire warmers.