Tyres and Tyre Gauge Testing

[67cj5]

G'day folks seeing as I can't get about I decided to buy another set of ARB Tyre Gauges to use with the Twin Beast, I already had one set for the Single which all proved to be really good and spot on between the three of them, First off is their blue inflator Annie Log version or how ever you spell it and then The Red Ezi Deflator closely followed up with the 3.5" Low Pressure Gauge that goes from 0 to 50 in 1psi steps much to my surprize they are all right on the money,
After buying the Twin Pump and the Accessories Bag I thought I'd add another set of gauges, One for each pump, anyway I got another Blue inflator free when I bought the Twin so I just bought another 3.5" Low Pressure gauge @£15.00/$19.65 and another Ezi deflator which cost me £40.80/$53.45c, with a total of 6 gauges in all I did a side by side and they were all absolutely spot on except Number 2 Low Pressure Gauge which is off by 0.5 PSI, Bugger

Not to worry I can live with that or if it annoys me I can adjust it Que Sara Sara, Which after some more testing turned out to be operator error.
Also I bought another Hose kit giving heaps of spare bits and another 6 metre length of hose so I have two sections to use with either compressor or with the 4 in total + 24m/80ft of Air Line.
While I was waiting for the delivery man I got on ebay and I saw cheap Deflators @ £5.99 + £1.99 postage $10.45 mmmm ?? Click click and I bought 2, they weren't meant to be here til the end of next week YarHooooooooo more Toys

Anyways after testing the ARB's out I though I'd give em a look see, First one absolutely spot on with the ARB's " Happy Day's" Number 2 off by 0.5psi with a quick adjust of the dial it too is spot On.
I have seen the ARB Ezi Deflator on web sites for up to $59.34 and I have seen it over here for over $100 also so it just goes to show there are scalpers every where. But if you don't want to spend that much on one this cheapie is just as good and comes in a foam filled hard case with a spare Valve key and 4 valve caps and unlike the ARB version it has a needle rest button on the side at an 8th of the price,
Please note that all of these Gauges go up in 1 "ONE" psi steps.
This is the ARB 3.5" Low Pressure Gauge.

ARB Annie Log "Blue"

ARB Ezi Deflator

And this is the Cheap Alternative to the Ezi Deflator Note that the Gauge goes up to 75psi where as the ARB version only goes up to 60psi so if you camper or what ever uses over 60psi then you are better off with the cheapie. And to be honest I'd swear these two are made at the same factory. Because this one has the same Dial as one of ARB's other Gauges that I have seen, all the fittings are very snug and perfectly finished, and to be honest $8.13c Vs $59.34c If I was doing it all over again and know what I now know, I know which one I'd be buying first. Not to worry because a now have a set to measure others by.

 

[67cj5]

Back In the early 80's I came over here and I was pretty high up in Dunlop and when ever Jaguar HQ Factory had a problem they sent for Me, this all started when they fitted 3 new Axles and 3 new Gear Boxes in some of their cars and still couldn't get em to run right, took me about an hour maybe an hour and a half problem solved, Which then led to me getting in to mechanics and having my own workshops when I cam home,
This taught me to be fussy or OTT when it comes to things like Tyres but most of all in the back ground Gauges, as it did building motors etc, Tyres are one Item that can have a grave effect on us whether we are just going to the shops or an epic journey across Australia, Tyres and Brakes are the only two "Non" She'll Be Right Items on a vehicle and Tyres are the most vulnerable part of a vehicle, Not getting the pressures right can lead to all sorts of problems from blow outs and of coarse accidents and I have even seen Insurance Assessors refuse a claim due to incorrect tyre pressures,

Changing Tyre sizes also has a huge impact on getting those pressures right, When you go up in size the pressure needs to come down when you get to a certain size and bigger, The easiest way to do this is to chalk your tyres putting a 1"+/- band of chalk across your tyres say about 6 to 10 inches apart, Find a quiet straight bit of road with the vehicle unloaded set the steering straight and Chalk both front and rear tyres, Drive in a straight line for a couple of hundred yards and they reverse back up, and get out and check the chalk bands, If there is still chalk on the edges of the tyres then they are Over inflated and if you can still see faint traces in the middle with NON on the edges then they are Under Inflated, going up or down a couple "2" psi at a time will bring you closer to where you want to be, Once you have done this you then want to do the same thing fully loaded, you don't have to go and load the truck unless you have time on your hands but it would be wise to, or you can just wait until you are loaded and test it then.
you can also get and Idea when you have been driving in mud and then you hit the black top and drive for about 60 to 100k's because where the tyre is making perfect contact with the road the tread area will be black and the area if over inflated the edges will still be greyish or if under inflated the edges will be dark black and the centres not so much ??,
There are 3 ways + another 3 ways to set your tyre pressures but the best way is, 1) In the shade in the morning 2) If you are a night driver then do it at night 3) when you have been driving the Vehicle, and of coarse at the same 3 times only this time fully loaded,

Airing Down
This is another grey area where people just ask their mates, But my Challenger weighs a lot less than your 3 ton Cruiser so your 20/25 psi what ever won't work for me, Dirt roads, wash boards and forest tracks you need to drop your tyres by about 25%, Rocks and Mud need about 30/35% and soft sand needs up to 50%.

Airing Down For Extreme Conditions
This is used "ONLY" in extreme conditions like Snow and Deep Snow Icy Conditions or Bull Dust. DO NOT use someone else's Gauge when doing this because if you set your pressures with your Gauge theirs might read +/- of what yours says and in this situation a couple of psi really matters which is why I have made sure that all my Gauges match,
To get "your" Extreme Low Pressures, Get your Truck on Level ground, Concrete is best, You will need a Tape measure or a ruler but if you use a ruler don't forget to allow for that blank bit on the end unless you are using a steel rule/ruler. 1) Look at the sidewall of your Tyre and read the maximum pressure stamped on the sidewall, If it says 44psi or "what ever" It could say 36, 50, 56, 65 what ever you brand has on it, IE So it might say 44psi, So Inflate your tyre to 5psi lower than what is printed on the Tyre, IE 44psi inflate it to 39psi, Now measure the lowest edge of the rim and say it says 148mm, get a calculator and take that 148mm and times it by 0.75 or .75 which (75%) So 148 x 0.75 = 111, which is 111mm, Now Lower your tyre pressure until the lower edge of the rim is 111mm from the road surface and then take a pressure reading and that is your absolute lowest pressure that you can go, when set to this pressure do not make fast turns and your speed needs to be no more than 10k's 12k's "MAX" and steer/turn very gently slowly, this will get you out of just about anything, forget wheel spinning etc or you will pop the bead, If the conditions are as described you can Drive for miles like this as long as you keep your speed down and are gentle on the steering. If conditions allow or you can travel up to 20kph if you increase the pressures up by 5 or 10psi as long as you keep your speed under 20ks ish.

Here are the tolerances of gauges that use a fully geared, solid brass precision movement with bronze bourdon tube, I get all my Gauges and measuring gizmo's Calibrated by someone I know at British Aero Space, he even gives my Straight Edge's the once over.
The mechanical accuracy rating is ± 2% from 25% to 75% of scale and ± 3% below 25% and above 75%.
A 15 psi tire gauge is accurate to ± 0.5 psi from 4 psi to 11 psi and is calibrated to ± 0.25 psi at 7.5 psi.
A 30 psi tire gauge is accurate to ± 0.6 psi from 8 psi to 22 psi and is calibrated to ± 0.5 psi at 15 psi.
A 60 psi tire gauge is accurate to +/- 1.2 psi from 15 to 45 psi and is calibrated to ± 1 psi at 30 psi.
A 100 psi tire gauge is accurate to ± 2 psi from 25 to 75 psi and is calibrated to ± 1.5 psi at 50 psi.
A 160 psi tire gauge is accurate to ± 3.2 psi from 40 - 120 and is calibrated to ± 2 psi at 80 psi.

When I ordered the cheaper Red Deflators I also ordered a Tyre Gauge and Deflator Kit which includes a protective box a tyre gauge that goes up to 100psi and 4 Deflators in a pouch that look a lot like the staun deflators, The Quality is right up there, As with the other Gauges I had to remove the Bezel/Glass to put the needle the right side of the stop post, This appears to be how they ship them because they all came shipped the same way which is a quick and easy fix. The cost of this Kit was $16.37usd including free shipping from Norway

No I am not joking, They did Actually come from Norway.

I tested the gauge and it is spot on so I'm pleased about that, Then it was time to set up the 4 Deflators, I set the first one pretty quick, hat was easy with the use of the ARB Low pressure Gauge, No 2 was a bit of a task because I was determined to get them absolutely spot on then I worked out a quicker way of setting them and got them all done in a couple of minutes,
Although Deflators are really good, Nothing dumps Air like the Ezi-Deflator or the cheaper Red copies "which" I swear are made in the same place. If you see these on sale in the US or where ever you are they are worth the money and do the job

 

[PJorgen]

Well that explains “Tyres”...

 

[67cj5]

Well that explains “Tyres”...

Yes, it is one of those subjects that has so many facets to it, whether it is 4x4/overland tyres or car tyres and of coarse Racing tyres and many more from Big Rigs to Earth Movers, I have fitted them all at one time or another,

I have just added another Gauge to the kit because I wanted to do some testing on Racing tyres so I bought the Longacre Magnum 3,1/2" 0 to 15psi Gauge, It is a thing of beauty and as soon as the store has them back in stock I will order the others in the same range because of their High Accuracy, It has a Glow In the Dark (GID) Dial and has 1/4Lb increments which is a nice touch and comes in an Alloy Case, they also make a 0 to 30psi and a 0 to 40 version and 0 to 60psi version all with 3,1/2" Dials, they also make 2,1/2" versions as well as the standard 2" version all with either 1/4, 1/2 and 1 PSI increments. and then they do a Liquid filled range and then the full On Race Temperature Heat Compensated Digital Gauges for about $400.00 each, and the list goes on,

Anyways I hope the above two posts helped.