![]() |
![]() |
|||||||||
|
||||||||||
![]() |
![]() |
|||||||||
|
||||||||||
![]() |
![]() |
![]() |
#1 | ||
![]() Veteran
Join Date: May 2003
Posts: 11,142
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
Tyre Pressures in Trailer Tyres.
I've always run my trailer tyres at around 35-40psi pressure. I recently got a couple of tyres for someone and the sidewall figures said 90psi, these were 12 inch 8 plys. I've just bought myself a pair of 6 ply 13 inch and the figures read at 65psi, the tyres I've taken off say run at 45psi.
So should I be running the pressure at the amount it states on the sidewall or a bit lower as I am not loading them to the maximum amount? The sidewall states maximum weight of about 680kg Twin axle trailer probably grossing about 1800 kg maximum, except when I load it with hay and then it may go to over 2 tons. |
||
![]() |
![]() |
![]() |
#2 | ||
Veteran
Join Date: Dec 2001
Posts: 6,358
![]() ![]() ![]() ![]() ![]() ![]() |
The pressure marked on the sidewall is the maximum pressure to which the tyre should be inflated. Optimum pressure for a given application will vary & will always be lower than the permissible maximum.
|
||
![]() |
__________________
Doing an important job doesn't make you an important person. ![]() |
![]() |
#3 | ||
Veteran
Join Date: Aug 2004
Posts: 14,699
![]() ![]() ![]() ![]() |
Tim take this advise from someone who mulled no less than 3 tyres in one trip a few months ago and fortunately I have a 6 wheel trailer or lord alone knows how I would have got home. I made the same assumption looked at the sidewalls 90psi, got a heavy car so thought way to go 80psi in each. On the way homeI lost two tyres where the rubber valve had literally blown out under the pressure as I am sure they increased as it was a hot day and did the third one in pulling out of a garage after having to stop every few miles to top up pressures. Its only then I realised the original tyres fitted by Brian James had metal bolt in valves so the moral is you must use these if you are going to run high pressures. I have now dropped down to 45psi with rubber valve stems and have had no further problems and they dont look under inflated at all.
|
||
![]() |
__________________
You can't polish a turd but you sure can sprinkle it with glitter! ![]() |
![]() |
#4 | ||
Rookie
Join Date: Apr 2011
Posts: 43
![]() |
Size, type and load on the tyre govern optimin pressure.
I have a plate on my trailer (BJT) which tells me what to run at for a selection of tyres. Which is usefull. 35 psi is what I use. ![]() |
||
![]() |
__________________
Just when you think your software is Idiot proof, somebody comes up with a better Idiot ![]() |
![]() |
#5 | ||
Veteran
Join Date: Sep 2006
Posts: 946
![]() |
We had a spate of tyre problems with a Motor Shuttle until we upped the pressure to about 80psi.
If the manufacturer of your trailer still exists, talk to them. |
||
![]() |
__________________
Andrew Cliffe - Norwich Photo & Racing Exposure ![]() |
![]() |
#6 | ||
Veteran
Join Date: Nov 2006
Posts: 9,427
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
I use 8ply caravan tyres on my race box inflated to 45psi never had a problem, running road tyres at 80psi is asking for trouble if it is "handling" wrong then it is loaded wrong !
|
||
![]() |
__________________
Balls of steel (knob of butter) They're Asking For Larkins. ( Proper beer) not you're Eurofizz crap. Hace más calor en España. Me han conocido a hablar un montón cojones! Send any cheques and cash to PO box 1 Lagos Nigeria Africa ! ![]() |
![]() |
#7 | ||
Veteran
Join Date: Nov 2006
Posts: 9,427
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
There is a formula for working out tyre pressures, on the side of your tyres there will be a " maximum load single " at a maximum psi .
Lets say for example , it states 1460kg at 65psi on your tyre , and your trailer or caravan weighs 1075kg . What you do is 65 divided by 1460 = 0.0445 Then , times 0.0445 by 1075 = 48psi . |
||
![]() |
__________________
Balls of steel (knob of butter) They're Asking For Larkins. ( Proper beer) not you're Eurofizz crap. Hace más calor en España. Me han conocido a hablar un montón cojones! Send any cheques and cash to PO box 1 Lagos Nigeria Africa ! ![]() |
![]() |
#8 | ||
![]() Veteran
Join Date: May 2003
Posts: 11,142
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
Gordon, the weights stamped on the tyres are per tyre not gross weight, in my tyres case It's 640kg per tyre and 65psi
|
||
![]() |
![]() |
![]() |
#9 | ||
![]() 1% Club
Join Date: Dec 2002
Posts: 46,858
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
I dont like 38psi in my road car as its too hard, imagine what 90psi would do in a trailer
![]() You would have to imagine the trailer would bounce a bit (lot), having very little give in the sidewalls at that pressure to absorb even the slightest bump... |
||
![]() |
__________________
Go woke, Go broke… Here’s hoping a random universe works out in your favour.. ![]() |
![]() |
#10 | ||
Veteran
Join Date: Sep 2006
Posts: 946
![]() |
Use the right tyres for the job, and run the pressures recommended by the tyre or trailer firm.
|
||
![]() |
__________________
Andrew Cliffe - Norwich Photo & Racing Exposure ![]() |
![]() |
#11 | ||
![]() Veteran
Join Date: May 2003
Posts: 11,142
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
BJ recommend 36.2psi for my original tyres on my trailer which the sidewalls state 45 at full load. My new tyres have a stated pressure of 65 psi at full load and while I wouldn't run that high I think 36 will be too low.
|
||
![]() |
![]() |
![]() |
#12 | ||
Racer
Join Date: Aug 2001
Posts: 221
![]() |
a simple rule of thumb is the trailer tyres needs to be inflated for the weight of itself and the car its carrying. On my 4 wheel trailer with a fiesta on board, i would put pressures equivilent of say a road going focus (35ish psi) - certainly not 80-90 psi which is dangerously overinflated.
|
||
![]() |
![]() |
![]() |
#13 | ||
Veteran
Join Date: Aug 2004
Posts: 14,699
![]() ![]() ![]() ![]() |
I dont think its dangerously over inflated if you have tyres built for the job and bolt in valves. The 10inch tyres on my 6 wheeler have 95psi stamped on the side as max so I am sure they must be safe at that with the obligatory bolt in valves (see my previous post), don't forget the BJ 6 wheelers is designed to take a fully loaded LWB sprinter in fact I have a customer who has a recovery firm and he has had to turn jobs down with his fleet where this trailer would have coped. Again though for carrying my 1400kgs Camaro I won't use them at anything like that pressure.
|
||
![]() |
__________________
You can't polish a turd but you sure can sprinkle it with glitter! ![]() |
![]() |
#14 | |||
![]() Veteran
Join Date: May 2003
Posts: 11,142
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
Quote:
|
|||
![]() |
![]() |
![]() |
#15 | ||
Veteran
Join Date: Apr 2007
Posts: 2,715
![]() |
For many years I've run a 4 wheel trailer on 145/80 X 12 tyres and always run at 45 lbs pressure.
I always now carry 2 spares as many years ago I was taking a friends race car to him in Harrogate and I must have run over something on the kerbside as both nearside tyres disintigrated at the same time. |
||
![]() |
![]() |
![]() |
#16 | ||
Racer
Join Date: Nov 2004
Posts: 289
![]() |
One question being missed here, are you running commercial tyres or road tyres ? 8 ply are commercial trailer tyres so would expect to run them at higher pressures than the equivilant 6 ply road tyres.
|
||
![]() |
__________________
don't lift, don't lift, don't lift - damn you lifted again !! never will get those tyres hot... ![]() |
![]() |
Thread Tools | |
Display Modes | |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
tyre pressures vs tyre temps | ozracer | Racing Technology | 19 | 18 Nov 2016 12:06 |
Tyre Pressures | Ilikeearlgrey | Racing Technology | 18 | 27 May 2005 18:29 |
Tyre Pressures | Pug620 | Racing Technology | 14 | 8 Feb 2005 19:47 |
tyre pressures | laser2 | Racing Technology | 9 | 20 Aug 2003 12:29 |