How to Determine Max Wheel Diameter for an Idler Hub

Updated 04/19/2018 | Published 04/18/2018

Question:

What all do I need to know to match a small trailer rim to an existing hub. I understand about the number of bolts and the bolt hole Circle. How does the outside diameter of the Hub and inside diameter of the rim coming to play. Do they have to match. Or can the rim be a little bigger. So what I am asking is will any trailer rim with a 4.5 bolt circle fit a trailer hub with a 4.5

asked by: Gene

Expert Reply:

As you mentioned, you will need to match the number of bolt holes in addition to their spacing in order to fit a wheel to a trailer hub. This is known as the bolt pattern and you can use the attached help article to help you find which pattern you have. There are actually 4 different bolt patterns that use 5 bolts such as a 5 on 4-1/2", 5 on 4-3/4", 5 on 5", and 5 on 5-1/2" therefore you will need to measure the spacing in addition to counting the holes.

In regards to wheel size, the overall diameter of the idler hub will play a factor in determining the overall diameter of the wheel that can be used on that hub. However, the best way to determine max wheel size would be to know the weight capacity of your axle. For example, if you have a 2,000 lb axle with a 5 on 4-1/2" bolt pattern then the recommended wheel size is between 8" and 12". If you have a 3,500 lb axle with a 5 on 4-1/2" bolt pattern then the recommended wheel size is between 13" and 15".

expert reply by: Conner L