# Tyre Pressures on Smart Car Trailer



## tonybvi (Jan 31, 2007)

I have a Brian James MicroMax trailer for towing my Smart car. The trailer is fitted with Hankook 155/70R12C tyres which I have been happily running for several thousand miles at 45psi pressure without any problem. Spurred on recently by the purchase of a tyre pressure monitoring system I thought I would check the correct (recommended) pressure, thinking that it would be somewhere around the 40-50psi mark. I eventually found a small sticker on the trailer which gave recommended pressures for different tyre sizes - recommendation for 155/70R12 was 90psi!! Note that the max. pressure noted on the sidewall is 95psi. I contacted Brian James to verify this surprisingly high pressure and although they agreed that this was correct they suggested running at 70psi.
Even this seems on the high side to me - what pressure does anyone with similar tyres on their trailer run at?
Thanks
Tony


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## Medallionman (Nov 26, 2005)

90 psi on mine also.


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## raynipper (Aug 4, 2008)

Must be bouncing along like a Pogo-Stick.

My trailer with 13" wheels and usual 350kg. load runs well at 40 psi. But when I get it loaded with 1500kg. (yes I know) I pump the tyres up to 55 psi and it runs very smoothly.

Ray.


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## HarleyDave (Jul 1, 2007)

I collected our "new to us" Woodford Smart Car trailer last night and have spent part of today tidying some of the wiring and generally "titivating" (as you do)

I called Woodfords with the serial number and they were instantly able to tell me date of manufacture, original spec etc etc (even who it was originally delivered to...) and advised the tyre pressure should be 40psi.

This figure was confirmed by the spec. plate which also showed the gross weight as 1300kg with a load capacity of 980Kg

Like the Brian James trailers, the tyres are 155/7R0/12C so I'm not sure why there should be such a discrepancy in recommended tyre pressures.

Cheers

Dave


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## harveystc (Sep 20, 2008)

*Tyre pressures on smart car trailer*

Hi,I have a smart trailer and always run at 45 pressure,95 sounds unstable to me i only have 45 in my other trailer and its longer and carries more weight,and only 65 on the rear of the motorhome as it is always loaded,regards H


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## bubble63 (Sep 30, 2009)

hi
brian james trailers have a data plate on , at least all mine have

one of the boxes is tire pressure

mine is a bantam smart trailer, recommended pressure 2,3 bar

hope that helps

neill


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## HarleyDave (Jul 1, 2007)

2,3 bar is even lower pressure = 34psi !!!

Stranger and stranger...

Cheers

Dave


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## tonybvi (Jan 31, 2007)

Thanks for all your replies so far. If anybody is interested the trailer data plate gives the following pressures for a range of tyre sizes for a max weight of 1300kg.
145/80R10 2.5bar (35psi)
140/70R12 4.25bar (60psi)
155/80R13 2.5 bar (35psi)
165/80R13 (8 ply) 4.5bar (65psi)
195/55R10 6.5bar (90psi)
155/70R12 6.5bar (90psi)
165/80R13 2.5bar (35psi)
195/50R13 6.5bar (90psi)
So a wide range of pressures - 35 to 90psi - for a range of tyres!! As I said in my original post my tyres should be at 90psi but this is far too high for my liking. Despite BJT confirming that this was the correct recommendation but also advising that 70psi would give a better ride I have made an executive decision and will run them at 50psi - slightly higher than what I have been running at but nowhere near the recommended pressure!!

Tony


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## johnthompson (Jul 29, 2010)

I have a "Bantam Smart Car Trailer" not a Brian James but "The original Smart Car Trailer".

It has a plate on the side with Tyre pressure of 65psi on it.

I have tried running at lower pressures and the tyres run hot and bulge out when the car is loaded.

The first tyres didn't last long and went egg shape while running at 45psi. The garage had serviced it and let the tyres down as they thought they were too high.

When I had new tyres fitted they blew them up to 28psi and they were almost touching the rim when I loaded the car. The trailer ran great empty at 28psi.

John


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