Olympic Steeltreks

[dreamin']

I have just picked up a set of Olympic Steeltreks for my Dormobile. They look good and ride A LOT better than the recap crossplies they replaced.

Can anyone tell me what tyre pressures are best for these - sidewall says test inflate 85 psi but assume this is not normal running pressure?

Roger

[Lotz-A-Landies]

Roger

The pressure label on the sidewall is the maximum tyre pressure.

The OEM owners manual for the 109 SIIa lists 25PSI for loads under 250Kg and 36PSI for loads over 250Kg

In the 88" its 25 and 30PSI respectively but that is on 6.00 16 tyres.

Diana

[rick130]

A radial needs vastly different tyre pressures to a bias/cross ply tyre as the case construction is so different.

WAG suggests starting at 40-45psi for a 7:50/16, then adjust from there, according to sidewall bag and contact patch.
ie. what's best depends on the vehicle and it's weight and what it's being used for, eg.highway pressures are a lot higher than what you'd use for predominantly dirt/gravel roads.

[Blknight.aus]

when I had them I used to run 30 all round in a LWB.

[rick130]

when I had them I used to run 30 all round in a LWB.

Strewth, what are they ? a sixteen ply ?

7:50/16's seem to need a lot more air in a 110/130

[Blknight.aus]

not surprising, your carrying nearly a ton more weight than a stripped down series.

Cant find my copy of the EMEI that details the inflation pressures for you.

[JDNSW]

A radial needs vastly different tyre pressures to a bias/cross ply tyre as the case construction is so different.

WAG suggests starting at 40-45psi for a 7:50/16, then adjust from there, according to sidewall bag and contact patch.
ie. what's best depends on the vehicle and it's weight and what it's being used for, eg.highway pressures are a lot higher than what you'd use for predominantly dirt/gravel roads.

The Series 2a owners handbook gives 25/25 (36) (loaded for a 109) on crossplies, and 20/20(35) for for radials. Yes, radials need different pressures.

The Steeltreks are very solidly built, and use of these low pressures on road will result in damage. I find that for on road, 35/35(45) and 25/25(35) round the property works well with them.

John

[Lotz-A-Landies]

The tyres are not branded for ply rating, but they react and have load ratings similar to 12 ply and remember the Army who were the largest customer for these particular tyres are not into using low ply rating tyres.

[goanna_shire]

Just a word of warning. They like to fall/fly to pieces at about half worn out. I have had 3 out of 5 do it on my perentie at 42 psi in the middle of nowhere.

Just my 2 cents I

[Lotz-A-Landies]

This is why the Army replacs the tyres bases upon a timeframe rather than a wear basis.

The reason is that rubber is porous and when vehicles stand in a single place for long periods, particularly on unpaved surfaces like Army pool vehicles do, the moisture can get into the tyre and rust the steel belt. This will cause delamination, hot spots and tread failure, as depicted in goanna_shire's post.

The rules are:

• When purchasing second hand Army tyres, have a very close inspection feeling the inside and outside of the casing for lumps and bumps. If present, don't buy them.
• Try to avoid parking your part time drive vehicle on dirt surfaces.
• Do inspect the tyres carefully prior to each use after a period parked up and also at the first rest stop on the next journey.

Bias ply (cross-ply) tyres usually don't have a steel belt and don't suffer the rust problems. This is one reason for using conventional bias ply tyres for our historic vehicles.