tire pressure

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glenn of northport
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tire pressure

Post by glenn of northport » Tue Sep 24, 2019 5:24 pm

what is tire pressure 0n 30 by 3 tire


Allan
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Re: tire pressure

Post by Allan » Tue Sep 24, 2019 5:39 pm

I run at 60 psi. Certainly never less than 55.
Allan from down under.

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john in kzoo
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Re: tire pressure

Post by john in kzoo » Wed Sep 25, 2019 9:19 am

agreed at 60

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Steve Jelf
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Re: tire pressure

Post by Steve Jelf » Wed Sep 25, 2019 9:47 am

I run at 65 front (30 x 3) and 70 rear (30 x 3½), so if they lose five pounds before I check the pressure they're still OK.
The inevitable often happens.
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Russ T Fender
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Re: tire pressure

Post by Russ T Fender » Wed Sep 25, 2019 1:02 pm

The early treatises call for 20 pounds per inch of tire on clincher rims. That's 60 front and 70 rear.


Rich Bingham
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Re: tire pressure

Post by Rich Bingham » Wed Sep 25, 2019 1:56 pm

Would you recommend over 70psi for "oversize" 30x3-1/2 tires ?
"Get a horse !"

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HalSched
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Re: tire pressure

Post by HalSched » Wed Sep 25, 2019 3:13 pm

I called Lucas Tire and a real friendly reply on 30 X 3 1/2 tire pressure was 65 PSI. I've been running 50 or years so I'll have to bring mine up a little.

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Steve Jelf
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Re: tire pressure

Post by Steve Jelf » Thu Sep 26, 2019 12:50 am

I suspect letting the pressure get too low was why I lost a tire a couple of years ago. I walked back along both sides of the road and I never did find that tire. :)
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Jugster
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Re: tire pressure

Post by Jugster » Thu Sep 26, 2019 9:36 pm

Hi, Neighbor in Northport;

The reason we need to run high pressure in clinchers is to avoid shearing the air valve off the inner-tube. Higher pressure forces the rubber clinchers more tightly against the rim, thus preventing tire slippage. If the tire slips along the rim (and this tendency is strongest during heavy braking), the inner-tube gets stretched at the point where the air-valve pokes through the rim and that can cause it to tear apart. This problem is much more prevalent in the case of the rear tires because they are subjected to the fore and aft loads of acceleration and braking. Not so, the front wheels, the most significant problem of which is the kind of excessive side-load you get when rounding a corner at too high a speed (which is not only bad for the tires, but for the wooden spokes as well).

Point is, you have some "wiggle room" when it comes to deciding on the proper inflation pressure of your front tires, and if you run them at, say, 50 pounds instead of 60 pounds, the front passengers will feel the car riding much more smoothly (and I run my driver-side front tire a little softer than the passenger-side front tire in an effort to counteract the natural tendency of a Model T to pull to the right on a crowned street, so I'm working with three different inflations). But as always, take corners slowly so as to avoid peeling the tire off the rim or shattering the spokes.

There's not a whole lot we can do about reducing the acceleration and braking impulses at the rear wheels. In a Model T, those forces are already minimal compared to most any other kind of car and reducing them further is not really possible. The usual vacuous advice applies and all you can do is inflate to the recommended pressure and drive gently.

Your Neighbor in Commack


Alan Long
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Re: tire pressure

Post by Alan Long » Fri Sep 27, 2019 4:26 am

Looking at my tyres (tires) they show slight signs of under inflation wear pattern. I would guess that increasing the pressure
from 69 to 65 PSI would cure this. But Boy oh Boy, I get very nervous pumping up tyres to 60 due to the poor quality Tubes we have to tolerate these days. Tube issues is another pet hate of mine. Alan


Alan Long
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Re: tire pressure

Post by Alan Long » Fri Sep 27, 2019 4:27 am

Should read from 60 to 65


art32mor
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Re: tire pressure

Post by art32mor » Mon Sep 30, 2019 12:40 am

55-65
But if less then 55 youl get good a fixing flats

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