20 replies to this topic

[YELLAcakeu308]

Hi all.
Looking at replacing my car trailer tires soon.
Its a tandem with 205 /65 15 at the moment.
Anyone here running the 15" rims?
What brand/ size you running?

[Ice]

I would be buying light truck tyres if it was me

[grumpy xu1]

I would probably agree with Gene, there's a lot of constant weight there. & your pride & joy, isn't cheap. A quality tyre shop, should steer you the right direction though.

[limo]

Light truck on mine. I use 13" Torana rims though . Tyres aren't dear.

[ozyozyozy]

Im with the others.
I run 15in light truck tyres, cheap, easy to get.
Doesnt really matter what brand.

[Bigfella237]

Coupla things... have a look at your trailer's compliance plate, they typically have a "TYRE SIZE/PLY" nominated and much the same as a tyre placard on a car, that's what you're legally supposed to fit.

 

Also look at the "AGGREGATE TRAILER MASS" (total mass of trailer including maximum load), divide that by the number of road tyres (so divide by 4 for a bogie axle trailer) and that is the minimum "LI" or Load Index of the tyres.

 

So if for example your aggregate mass is 2500kg divided by 4 then you need tyres with a minimum LI of 92x ("x" being the speed rating) or 630kg per tyre.

 

There is a "LI" chart here:

 

https://www.tyresize...oad-index-chart

[hanra]

I would call into a Tyre shop to discuss what tyres they sell. You dont want to waste money buying the incorrect tyres. Tyres are very important. The tyre shop should be able to point you in the right direction. 

[Rockoz]

Tyre shop wont put anything but light truck tyres on a car trailer.

My local one is actually quite anal about the rules.

Couldnt even get a second hand tyre off him to put on a project car just to move it around.

[YELLAcakeu308]

Thanks all for your input.
Aggregate trailer mass is 2000kg
Tyre size/ply. = 15 inch 8 ply

I agree light truck tires would be the go.
At the moment with the drop thank & big front spoiler i definitely don't won't a taller tyre.
As my trailer is only a beaver tail.
A smaller rim & tyre conversion would help but I'm guessing the trailer would have to be re certified.

[YELLAcakeu308]

Limo, is your 13" litght truck combo smaller in height than a 205/65/15 ?

[caterham2]

I bought a really nice tandem car trailer a while ago which came fitted with passenger car radials. The difference loaded with light truck tyres under it was amazing. Get some advice re pressure when you buy them, some of these need to be run at 60 PSi +/- to be really effective.

[Heath]

I bought a really nice tandem car trailer a while ago which came fitted with passenger car radials. The difference loaded with light truck tyres under it was amazing. 

Could you expand on that?

 

Rolled better? Stayed more steady at speed? What was the improvement?

[Shiney005]

If you are wanting to go to the 13 inch rim to get the trailer lower, that will come with the penalty of more heat in the smaller tyres for any given speed. I use 17.5 inch tyres on my float behind the truck, but I won't tow anything over 20 tons at more than 85kph. If I was using the 22.5 inch tyres (as fitted on the truck) it would be safe to sit on 100.

 

 .1abcz (129)small.jpg   225.26K   1 downloads

[Bigfella237]

At the moment with the drop thank & big front spoiler i definitely don't won't a taller tyre.

 

Can you get longer ramps made?

 

Or more to the point, have you got space to stow longer ramps on / in / under the trailer somewhere?

[YELLAcakeu308]

Bigfella237. The bloke I bought it off had to extend the ramps about a half a meter from memory.
He was racing vs commys @ speedway.
Most likely the reason it has ford bearings & is commodore stud pattern

[YELLAcakeu308]

^ extended for my car.
Even wwith no engine we couldn't put the monza on the tralier using his original ramps lol

[caterham2]

Could you expand on that?

 

Rolled better? Stayed more steady at speed? What was the improvement?

 

Don't recall if it rolled better, but the stability was vastly improved, sway all but eliminated etc. Tow car was a Falcon AU ( yeah I know) , the coil spring rear suspension is not the ideal but with a Xu1 Torana on board was great after LT tyres fitted.

 

[YELLAcakeu308]

Took the spare around to a mates trailer to put alongside his 14's with lt tires

Attached Files

•  Screenshot_2019-07-07-18-55-11.png   1011.74K   0 downloads

[YELLAcakeu308]

Obviously theres a little bit of trailer weight on his 14" ,
But its maybe an inch shorter than my 205/65/15.
Which would make loading / unloading alot easier

Question :
Does anyone here know the minimum height clearance for the rear of a trailer?

Attached Files

•  Screenshot_2019-07-07-18-55-22.png   744.82K   1 downloads

[Bigfella237]

From third edition ADR43 (which the Trailer Construction VSB's also refer to), with the trailer fully laden, the rearmost overhang must clear a 1:15 gradient.

 

So if you were to park the rearmost tyre on say a 3 metre length of string and hold the other end 200mm off the level ground, every part of the trailer would need to clear that string line.

 

 

Or if you need a longer piece of string, 4.5 metres back would be 300mm off the ground.

[YELLAcakeu308]

These are tyres currently on my trailer.
They are rated the same as the tire shop suggested today over the phone.
Got a feeling I've been running to low psi in them... (35psi)

Attached Files

•  Screenshot_2019-07-08-17-43-44.png   820.52K   0 downloads
•  Screenshot_2019-07-08-17-43-31.png   939.87K   0 downloads