MTFCA Forum

A participant in our recent tour suggested you fellows may be interested in these two photos.
Both cars are set up by a well respected, long time T owner, and both have covered about 3000km. The Wards Riversides are about 1/2 worn wjile the Blockleys still have the mould pips on the sides. Allan from down under.

The Blockleys may have a harder tread compound, which will extend wear at some expense in traction. A softer compound will give excellent traction , especially on pavement, but will wear faster, all else being equal. The Blockley tread appears to put a good deal of rubber on the road, which ought to help reduce wear and may improve traction on smooth pavement. High inflation pressure, especially on a lightweight car, will spare the outer edges of the tread while concentrating wear in the center area. Heavy loading or lower inflation pressure will do the opposite. A car driven mostly on straight, open roads may show less edge of tread wear than one driven mostly on curvy roads. Siped treads give good traction on wet roads, but may wear faster on dry roads.

The Wards tires are about half worn out at about 3000 Km (about 2,000 miles). This would imply that the tires would last about 4,000 miles. Is this typical mileage for Wards tires?

Art Mirtes

That sounds low to me. Conditions of use, and of the vehicle, and vehicle characteristics, all have a substantial impact on tread wear rates. Some drivers can destroy a set of tires very quickly, while others can keep tires in good condition for extended miles of service. Some road surfaces are a lot more more aggressive than others, and that affects tire mileage and traction. A coarse pavement surface will provide excellent traction, but it can chew up tires faster than a smoother surface.

I have 13000 miles on Universal T Drivers purchased in 2019. They still have some tread on them, especially the fronts. I recently bought another set of T-drivers to replace them....I had planned to get Blockleys but the tariff situation and general confusion over shipping put me off. I drive pavement 80% of the time, gravel the rest. I installed 6 oz of balance beads in each tube which may have helped. I also spent some time tracking down rims and wheels that run with little wiggle. I do use Blockley Tubes - they are clearly the best! I run about 63 psi per tire.

High ambient temperatures cause more rapid tire wear.

I can still see traces of the moulding dimples on the outer edges of the wards tread. It looks like the wear is more concentrated in the centre of the narrow tread Wards tyre, as would be expected. The wider, flatter tread on the Blockley tyre would mean a greater foootprint on the road and consequently less load on the tread.
On tours, these two cars spend much of their time following on another, often with driver changes at various stops. Both are well maintained by an experienced model T owner, making a comparison between the two easier to equate.

Allan from down under.

If I had the Wards tires, I'd try running a little lower inflation pressure. It's possible to wear the center tread of a tire to the cord while leaving close to half the tread on the outer edges by carrying too much air pressure for the load the tire is carrying. That's a waste of tire life. The Blockley tire appears to be wearing evenly.

Reducing the pressure to allow greater tread contact on the road is done to correct wear patterns on modern car tyres. My service centre just upped the pressure on my Mazda CX5 to take a make a bit more pf a crown in the tyres. I doubt you could lower the pressure in these little Wards tyres enough to make a difference without risking the tyre moving about on the rim and perhaps shearing off the valve stem.

Allan from down under.

A safe minimum pressure must be maintained. That said, the wear pattern shown indicates that some reduction in pressure would give better results. A tire that is undersized for the load it is carrying will typically show excess wear at the outer edges. According to Ford, the original equipment tires on Model Ts were fully adequate, and then some, for the car's loaded weight. A tire cannot deliver its potential service miles when irregular tread wear is occurring. Both under-inflation and over-inflation will reduce tire life and cause other problems, among them harsh ride, reduced traction, rim cuts, hard steering, poor fuel economy, and more.

Any idea what that 'safe minimum" pressure might be?

Allan from down under.

I'd have to guess, and my guess would be 55 PSI, cold for a lightweight car with one or two passengers. I don't know if there is any period information available that gives specific pressure/load figures. I came across an early table of load/psi recommendations, but they were for 4.40 up to 7.30 tires, which is no help for the 3.00 & 3.50 sizes.

I would say 1PSI more than the pressure where a tire will roll off the rim or will spin on the rim

You must have a very good tire gauge....

Model T Ford Forum: Forum 2018: Clincher tire pressure


I have "balloon tires" on my late roadster. Ford was all over the map with pressure recommendations. I run 25 to 27 PSI, cold, and get very good results. It seems that Ford, at some point, recommended 55 PSI for clincher type tires. Some have indicated that 50 PSI is sufficient for a light car. It looks to me like 55 is probably the prudent minimum, and that only on a light car. Over inflation and under inflation both bring problems.

** IN 1915, Ford recommended 55 PSI front, and 60 to 65 PSI rear. If I was running a 1915 roadster, I'd go with 50 front and 55 rear.

Might I suggest that "balloon tires " is confusing. Usually it applies to wider tyres, like 4.40' s on 21 inch T wheels. There were "balloon' 4.40 clincher tyres, before Chev went to 4.40 x 23'" straight sided tyres, but those clincher tyres were still high pressure tyres. I suggest "balloon tyres" are the low pressure tyres with straight sides used on split rims or drop centre wheels.
My Tarrant special tourer came with 4.40 x 23 clincher tyres as standard equipment. They were probably sold as "balloon tyres". I still have two of these on the rear, and two Chev rims with straight sided 4.40 x 23" "balloon tyres" on the front. The clincher rears run at 60 psi and the front straight sided ones at 35 psi.
Allan from down under.

The table I referred to mentioned "straight side" tires. The range of lower pressures (Well below 50 PSI) Ford specified were for tires designed for drop center rims. It appears to me that clincher type tires require a minimum of 50 to 55 PSI, cold, and that vehicle characteristics and loading often call for more pressure, with 60 to 65 PSI being typical. In actual use, wear patterns can be useful for determining suitable pressures, with a lightweight roadster having different requirements than a heavier, or heavily-loaded car. Both under and over-inflation will have adverse effects on the tire and the vehicle, with chronic over-inflation being especially hard on the vehicle.

It all comes back to the need for high pressure in clincher tyres to keep them from moving on the rims. If the minimum pressure on a light car is 55psi, and the crown on those skinny Wards Riverside tyres still wears, there is no room for adjustment to wear the sides down.

Allan from down under.

50-55 is prescribed for FRONT tires. 60-65 is prescribed for REAR tires. Driving & braking forces make tire pressure more critical for rears.
Another factor is how well the clinch holds the tire. A freshly powder coated rim that is very smooth is more likely to slip on a rear tire.

If soft tires wear more in the center (rear), some intelligent tire rotation & switching will get more life out of tires.
With the normal camber, the fronts wear the outsides more. Removing & mounting backside out(demountable or not) or putting that front on the rear (demountables) give more tire life.

I am a model T guy, frugality is a lifestyle.

A T tourer or closed car carrying 5 persons and/or luggage, etc, would carry more load on the rear than the front, thus requiring higher inflation to support the load, besides resisting drive and braking forces.

Ford owner's manual, 1926 HIGH PRESSURE TIRES:
Cars: Roadster & touring, Front, 55 PSI Rear 55 PSI.
Trucks: Front 55 PSI, Rear 80 PSI.

BALLOON TIRES:
Roadster & touring: Front, 27 PSI, Rear 27 PSI
Closed cars & Roadster P/U, 27 PSI Front, 30 PSI rear

Changes in tire construction over the years apparently resulted in lowering pressure recommendations for the high pressure tires. The cars actually got heavier.

My brother used to use Permatex on tire beads to prevent such problems. I have never tried it, but he was happy with results

Many old rims are rusted and otherwise damaged, which might be expected to affect the tire to rim fit. It would be a good idea to keep the casing and rim contact area free of any lubricant, so far as is possible. I would inflate a newly-installed clincher tire to 60 PSI for a few days to assure that it seats well to the rim. I'd avoid gluing the tires to the rims, since it seems they can be very difficult to remove, at best, after they've seated well to the rim. The weight of the earlier Model Ts can vary from about 1200 lbs to around 1800 lbs or more, depending on car type and loading. so some operator discretion is called for when considering tire inflation.

This is not going to help many people but just FYI. Old #4, 1915 2 passenger Model T Ford based race car, weighing in at 1520 pounds, under my 58 year stewardship has always run original 30 X 3 1/2 Wards Riverside tires. (still do!) For the last 43 years I have been running 47 pounds all the way around. The car carries no spare and I have had no tire problems. Prior to 43 years I ran 45 pounds or so, didn't pay much attention, but my first time racing at the Monterey historics, Laguna Seca raceway, the car handled so well that after our race was over I went around and checked all of my tire pressure and the average was 47 Pounds and I've stayed with it ever since. I do carry a spare tube just in case, and on one of our trips heading east through Colorado over the Rocky Mountains near Vail I felt the rumble of a flat tire. Pulled over and the left rear was flat. The valve stem was gone. Within a few minutes a guy in a pick up stopped and offered help. He had an on board compressor and in less than a half hour we were back on the road, heading to Lincoln Nebraska.

Ed aka #4