Tire pressure and ride feel

[scrollderf]

I changed out the worn front Maxxis to a Michelin Power Pure on my DT 300.I brought the wheel to a local auto repair shop that had been recommended to install mc tires. The mechanic is a mc rider and does mc work on the side. Re-installed the wheel and rode it for a few days both in town and on the highway for about 300 km. Speed from 40 kph to 110 kph. Seemed like a wonderful ride and experience. The grip and comfort seemed improved from the worn Maxxis. Changed oil yesterday and while the scoot was on the center stand I noticed a screw in the rear tire. Checked the pressure and it was normal, so left the well worn screw in place. Thought to myself that maybe I should also check the front tire pressure. Did. Pressure was 55 psi. OMG!! Mechanic must not have released the pressure down to the proper run pressure after seating the bead. After setting the pressure down to 32 psi (my normal), I went for a 100 km ride today mostly on 80 kph highway and some town roads. The feel and comfort was the same. Now my question for you is: why is the ride feel the same when grossly over inflated to 55 psi as when properly inflated to 32 psi. I had no idea at all that the tire was over inflated? So how does this explain the often seen suggestion to add or remove 2 psi to change the handling? Is the Power Pure such a good tire that over inflation was not noticed? Is the DT300 such a good mc that the over inflation was not noticed? It scares me that I could have had a blow out at 110 kph on the highway. Good scooter God on my shoulder!

[vespbretta]

If your new PP´s are RF tires (reinforced), it might explain your experiences.
Reinforced tire sidewalls are pretty stiff, so even a lower tire pressure wouldn´t make much difference in smoother riding feeling.
But 30 on the front (cold) and 33 on the rear (cold) should be fine as a good compromise for all riding conditions.

[Stig / Major Tom]

You gotta have some  s m o o t h  roads!
55 would have chipped a tooth on my LIKE200i.

Bummer about the screw in your new tire!
Yeah, that 55 psi is spooky - has to be beyond the safe max printed on sidewall. ?

Glad you got it sorted.
Stig

[scrollderf]

Robo seems to have a reasonable answer. But I would have expected a much harsher ride as Stig suggests. When I had the screw in the rear tire a few years ago, the tire never looked flat even with 0 psi, but of course it rode squirrley. I thought high pressure would lead to wander, but it did not. Good to know that the significantly higher pressure did not affect handling, which means riding safety may not be compromised other than the chance of a blown tire. Yes the tire was inflated well beyond the rating on the sidewall of 33 psi as shown on a photo on another post yesterday. As an aside: that was a lovely 100 km ride through the foothills west of town on a lovely 25oC day. Cheers everyone.

[hypophthalmus]

Personally, I have trouble noticing when my tire pressure is off, on scooters and cars alike. If it's at 0, thankfully I'll notice something feels weird on the scooter.

I'm also mystified when people mention different tires grip better. Of course I notice skidding. Is that what they're talking about though? Are they regularly skidding on some tires?

That said, there is a safety issue with overinflated tires. The contact patch is smaller, so there's less traction available to you. I think blow out is more of an issue with underinflated tires, because the tire changes shape more and overheats.

[klaviator]

I have owned numerous bikes.  On some a change in tire pressure is noticeable, on others it isn't until the pressure change is drastic.

[Redk]

I have owned numerous bikes.  On some a change in tire pressure is noticeable, on others it isn't until the pressure change is drastic.

Yes.
My experience also.
Probably has a lot to do with the tires sidewall, use of the cycle, frame geometry, and a few other things.
redk

[stuo]

I had a similar experience with a car tire. Now I always check the pressure when a shop mounts a tire for me. Who is going to be more concerned about your safety: the tire changer dude, or you?

[scrollderf]

When I went back to the mechanic to complain about the high tire pressure, he said that he always leaves mc tires at a high pressure and advises the owner to adjust the pressure to what they prefer as he has found there is so much variation of preferences. But he did not inform me of that policy. He did apologize and gave me a great deal on a subsequent car oil change. Happy ending.

[MJR]

Anybody tried one of these?

http://www.ebay.com/itm/Steelmate-DIY-TP-90-TPMS-For-Motorcycle-Tire-Pressure-Monitoring-System-2-Sensor-/201672685327?epid=655396085&hash=item2ef4a0f70f:g:O2cAAOSwyWZZW1OL&vxp=mtr