Does Larger Trailer Tire and Wheel Negatively or Positively Affect Braking Performance

Published 11/16/2021

Question:

Speaking to an engineer today. On a braked trailer, as wheel size increases the braking capacity decreases. So depending on the trailers brakes and their load rating, it may be dangerous to increase the wheel size. So as per your video and advice, the devil is in the detail!

asked by: Rob

Expert Reply:

That's a really interesting and valid point, but as we have found the trailer brake assemblies are easily more powerful than needed based on their capacity so if you had a 3,500 lb axle with matching brake assemblies they would very easily be able to lock the wheels up. And then if you were to increase the wheel diameter and in doing so decrease the leverage the brakes have over the wheels there would be enough power still to make up for it and lock the brakes up.

What the engineer you spoke with maybe didn't mention is that with a larger wheel and tire you increase the foot print of the tire on the ground as you travel so you have more traction to brake harder before locking the tires up so you actually could stop faster.

expert reply by: Jameson C