I have a trailer rated at 1 ton load but unbraked - so limited to 750kg,  I've obtained a replacement Alko axle and draw bar rated at 1300kg which will nett out at 1 ton load (trailer is 245kg),

Hubs are 100mm PCD 4 stud.

 

Question is what size wheels and tyres should  be looking for to support the gross weight of 1300kg?  I can fit 13 or 14" wheels withouit alteration and 15" if I moved the mudguards.

 

How many wheels does the trailer have?

 

What is the centre bore?

 

Possible centre bores for 4/100 rims

54.1mm

56.1mm

56.6mm

57.1mm

59.1mm

60.1mm

 

Edited 14 August, 20214 yr by Carlston

If your trailer weighs 245kg and expect to carry 1000kg then I’m basing it on 1245kg

 

For 2 wheels 622.5kg each, but need to add weight of wheel and allow bit of uneven loading (so more weight on one side).   Realistically therefore need a load rating of at least 700kg

95 is 690kg

96 is 710kg

You can buy XL (extra load) tyres and go up about 8-10%

 

but if I have misunderstood and max load per wheel is 500kg then load rating is only 84, but again allowing for uneven loading would be aiming for load rating of at least 91.    I suspect your load will determine minimum wheel size.

 

1 hour ago, Carlston said:

How many wheels does the trailer have?

 

What is the centre bore?

 

Possible centre bores for 4/100 rims

54.1mm

56.1mm

56.6mm

57.1mm

59.1mm

60.1mm

 

 

56.2mm, checked several times from different directions, so I assume that means a centre bore for the wheels of 56.6mm?

The hubs are outboard of the trailer body so (as I understand it) no offset is needed.

 

1 hour ago, SurreyJohn said:

If your trailer weighs 245kg and expect to carry 1000kg then I’m basing it on 1245kg

 

For 2 wheels 622.5kg each, but need to add weight of wheel and allow bit of uneven loading (so more weight on one side).   Realistically therefore need a load rating of at least 700kg

95 is 690kg

96 is 710kg

You can buy XL (extra load) tyres and go up about 8-10%

 

but if I have misunderstood and max load per wheel is 500kg then load rating is only 84, but again allowing for uneven loading would be aiming for load rating of at least 91.    I suspect your load will determine minimum wheel size.

 

 

Trailer is currently a 1000kg body/chassis and weighs 245kg but was imported with an unbraked axle and drawbar so it's road limited to 750kg load.

 

The Alko axle and draw bar I obtained are rated at 1300kg in total (is that Gross Vehicle Mass in new speak?) so when grafted together I will have a trailer weighing around 250kg empty (I will have to add in the extra weight for the heavier draw bar, axle and wheels) and capable of carrying a maximum load of 1,000kg (see earlier comment about weight differences).

 

From what you said (and with which I agree) I assume I'm going to be looking for "96" rated tyres?

 

Putting both sets of responses together I believe I'm looking for 4*100 wheels with 56.6 centres, no offset and to take a tyre rated at 96.  Does that sound about right?

 

As regards wheel sizes 14" feels about the right size - although I could run to 15" without surgery if necessary.  Any suggestions on donor vehicles with those wheel specs?

 

Thanks for the replies so far; much appreciated.

Edited 14 August, 20214 yr by MikeTheThinker

With trailers, it's the plated weight that is important. I suggest you plate it at 750kg. This is important if you don't have a category B+E on your driving licence. If you passed your car driving test before 1997 you will automatically have been awarded category B+E in additional to category B. Since 1997, an additional trailer driving test has been needed to be awarded the category B+E. If your trailer is plated for more than 750kg you can't legally tow it without a category B+E even if you don't have the trailer loaded to more than 750kg gross weight.

 

As you measured the hub centre bore at 56.2mm, I suspect that it is actually 56.1mm and not 56.6mm. 56.2mm would make the hub a very sloppy fit in a 56.6mm rim so I doubt it was made for that size.

 

Alcar 7160 4Jx15 ET35 4/100 56.1 Steel Rims

 

https://www.oponeo.pl/felga-stalowa/alcar-kfz-7160#19282293

 

https://www.mytyres.co.uk/rims/details?vehicleId=173418272467718756&rimCode=ALCAR7160

 

Vredestein Quatrac 5 155/60R15 74T

https://www.camskill.co.uk/m138b0s7984p133931/Vredestein_Tyres_All_Season_Car_Vredestein_Quatrac5_Vredestein_Quatrac_5_-_155_60_R15_74T_TL_Fuel_Eff_%3A_E_Wet_Grip%3A_C_NoiseClass%3A_1_Noise%3A_68dB

 

74 (375kg) load index allows for up to 750kg maximum axle weight. It's illegal to drive along with an unevenly loaded trailer.

 

Edited 14 August, 20214 yr by Carlston

i just learned a LOT in this thread..

52 minutes ago, Carlston said:

If your trailer is plated for more than 750kg you can't legally tow it without a category B+E even if you don't have the trailer loaded to more than 750kg gross weight.

 

That's not entirely correct.

 

Licences issued from 1 January 1997

If you passed your car driving test on or after 1 January 1997 you can:

• drive a car or van up to 3,500kg maximum authorised mass (MAM) towing a trailer of up to 750kg MAM
• tow a trailer over 750kg MAM as long as the combined MAM of the trailer and towing vehicle is no more than 3,500kg

https://www.gov.uk/towing-with-car

26 minutes ago, Schtum said:

 

That's not entirely correct.

Licences issued from 1 January 1997

If you passed your car driving test on or after 1 January 1997 you can:

• drive a car or van up to 3,500kg maximum authorised mass (MAM) towing a trailer of up to 750kg MAM
• tow a trailer over 750kg MAM as long as the combined MAM of the trailer and towing vehicle is no more than 3,500kg

https://www.gov.uk/towing-with-car

 

If the OP plates his trailer to more than 750kg he could easily run into trouble.

 

Let's say the OP plates his trailer at 1,500kg and tows it with a 2,000kg MAM car, then that's legal because the total MAM of the car and trailer hasn't gone over 3,500kg.

 

But if the OP swaps his car to one with a MAM of 2,001kg, he's driving with no licence as the combined MAM of the car and trailer has now gone over 3,500kg (ie. 2,001kg + 1,500kg = 3,501kg).

 

Edited 14 August, 20214 yr by Carlston

12 hours ago, MikeTheThinker said:

The hubs are outboard of the trailer body so (as I understand it) no offset is needed.

Not sure; what I do know is that the offset dimension is the distance from the hub mounting face to the centreline of the wheel, and you may need an offset dimension to get the correct track. This may be stated in the specifications for your new trailer axle.