Tyres + Wheels
Understanding Tyre and Rim specifications.
The terminlogy used for tyres, rims, wheels and wheel assemblies can be confusing, as there are so many styles, types and options available - from tractor tyres to shopping trolley castors, via ATV turf tyres and wheelbarrow wheels.
To help we have listed below some of the common phrases and measurements needed to ensure you buy exactly what you need.
High Speed Tyre and Rim.
High speed tyres are intended for use on trailers, caravans, boat trailers - anything that will be used on public highways. They are rated up to 60MPH, depending on the load being carried.
Measurements given for high speed tyres and rims look either like this:
4.80x8
In this example 4.80 is the tyre width, and 8 is the rim diameter.
or this:
20.5x8x10
In this example 20.5 is the tyre diameter, 8 is the tyre width and 10 is the rim diameter.
Low Speed Tyres and Rims
Low speed tyres and rims are intended for use in applications which are not taken on the public highway, like garden trailers, ATV trailers, trolleys, material handling carts etc.
Measurements for Low Speed Tyres and Rims look like this:
410/350x4,10.5"
In this example 410 is the tyre width, 350 is the tyre footprint width, 4 is the rim diameter and 10.5" is the tyre diameter
Pitch Circle Diameter
High speed trailer tyre assemblies are ideal for use as replacements on existing trailers or new build trailers. Studs are typically 10mm or 14mm in diameter.
When specifying 4 stud tyres and wheels, first measure the PCD (Pitch Circle Diameter) of your hub. This is the distance between the centre of the top stud hole and the centre of its opposite stud hole (see diagram):
If there is a small notch cut out of the centre circle, this means you have a 4" PCD. If there is no notch cut out, then you have a 4" 100 PCD.
Register to receive your FREE
Northern Tool Catalogue 
About Northern Tool
Website Tools
Why Northern Tool
Over 28 Years in Business 
Thousands of Products 
Low Trade Prices 
Top Brands 
Fast Delivery 
Knowledgeable Product Experts
Quick sign up
Email discounts, weekly exclusives and members specials
© Northern Tool + Equipment Co. (UK) Ltd: UK Registered office: Unit 2 Interchange Park, Portsmouth, Hampshire PO3 5QD Tel 0845 605 2266