Yet another tire pressure question

[tclardy]

Have been reading posts on this forum about air pressure in tires. The consensus seems to be that the pressures listed on the driveshaft and manual are too low.

I worked for four years in the auto tire business and on autos it is not recommended to look at the max tire pressure listed on the tire and use that as a basis for setting. Auto tire manufacturers recommend using recommendations of the auto manufacturer. The reasons for this are obvious, you might have one car that weights 4000lbs with a 60/70 front rear weight ration use the same size tires as a car weighing 3200 lbs with a 50/50 weight distribution. So they auto manufactures recommend tire pressure based on these factors and handling/ride/wear considerations.

That being said, I know almost nothing on bike tire pressures. I followed the recommnedations of some folks here and bumped the front to 36 and the rear to 40.

1. I noticed a definate difference in handling, the steering response is much quicker, did you notice same?

2. The ride was a little firmer, but I did notice it is firmer in the front and there is more road feel. Maybe it was just squirmy at 28psi, did you notice the same?

3. Do you think this will have any adverse effect on tire life, with raising the pressure up? I am a big guy 6' 3", 240 and occasionally take kid back that weighs 150.


Sorry to repeat the same questions, but just wanted to get others opinions. I have only had my vulcan for 3 weeks so I am a newbie to this bike.

Thanks,
Tim

[cboutfit]

I am just about to turn the big 15,000 and I am still running the stock front tire with lots of miles left on it. So yea I belive it has an effect, a positive one

[RichLockyer]

Tire life will improve with higher pressures.

The main thing often overlooked is the impact on hydroplaning.
Higher pressure = higher speed prior to the onset of hydroplaning.
I don't recall the exact formula, but studies done by the Navy at Pax River showed that at 28psi a tire will begin to hydroplane at 55mph. Bump that up to 35psi and the speed moves to 70mph. This is assuming legal tread depth and 3/16" of water collected on the road surface.

I've always run my tires at the max sidewall pressure and used to get 60k out of the 36k cheapies from Sears in my '91 Escort if I kept them rotated... if I didn't, the rear suspension would cup the tires in 10k.

I'm running my 285/75-16 BFG's on my truck at 65psi and after over 30k the wear pattern is within 1/32 across the face of all four.

[EdAZ]

Originally Posted by RichLockyer

Tire life will improve with higher pressures.

The main thing often overlooked is the impact on hydroplaning.
Higher pressure = higher speed prior to the onset of hydroplaning.
I don't recall the exact formula, but studies done by the Navy at Pax River showed that at 28psi a tire will begin to hydroplane at 55mph. Bump that up to 35psi and the speed moves to 70mph. This is assuming legal tread depth and 3/16" of water collected on the road surface.

I've always run my tires at the max sidewall pressure and used to get 60k out of the 36k cheapies from Sears in my '91 Escort if I kept them rotated... if I didn't, the rear suspension would cup the tires in 10k.

I'm running my 285/75-16 BFG's on my truck at 65psi and after over 30k the wear pattern is within 1/32 across the face of all four.

I am not concerned about tire life, I am concerned about traction and grip. Do you loose any with higher pressure than the MOM calls for....
What pressure are you running on your bike......

[RichLockyer]

Originally Posted by EdAZ

I am not concerned about tire life, I am concerned about traction and grip. Do you loose any with higher pressure than the MOM calls for....
What pressure are you running on your bike......

I shoot for 40/40, but it seems every time I check 'em they're both at 35.
I've never lost traction or even been WORRIED about it, but I'm not pushing hard in the corners.
The two times I've dragged my floorboards it's been at about 15mph

I believe you do improve traction in the mid inflation ranges... down to the point where the sidewall introduces too much squirm.

MOM is probably on the money for the best cornering traction.

[EdAZ]

Thanks Rich, Thats kinda what I thought. I run mine 2 lbs over MOM...30 FRT 32 REAR....