How to Choose Correct Boat Trailer Fenders

Updated 06/18/2025 | Published 04/19/2021

Products Featured in This Question

Galvanized Steel, U-Shaped, Bolt-On Brackets for Plastic, Single-Axle Fender PF11X35W (Pair)

(39)

$45.17

Question:

What fenders do I need for this boat trailer? Thank you

asked by: Ran

Expert Reply:

I didn't receive any information about your boat trailer, but I can explain how we classify them for you, which hopefully will help you to decide which fenders you want to go with. If you're only looking to replace one fender, unfortunately we have no way of looking up which exact fenders your boat trailer left the factory with. You might need to go with 2 fenders so they'll match.

We classify the fenders according to the wheel diameters they're compatible with. For instance, the Fulton
# F008583 you'd looked at is compatible with 13 inch wheels (13 would be the last digits in your tire size, like 185/30-13, for example). If you have 13 inch wheels, the # F008583 is a very popular choice that in addition to black that you'd already looked at, is also available in silver as part # F008593 or white as part # F008573. Mounting brackets for these fenders are available as part # PF1135-BKT-2. I've provided a photo showing how the brackets work.

I've linked to our selection of boat trailer fenders. Use the filters on the side of the page to narrow down the possible choices according to wheel size, material the fender is constructed of and the length of the fender.

expert reply by: Mike L

How Fenders Like # F008583 Mount to Trailer
(click to enlarge)

Kim K.

5/14/2025

How can you measure the UBolt size for these brackets?

Mike L.

6/18/2025

@KimK You'll want to choose U-bolts with a span around 3-5/8 inches an a length that's about an inch longer than the trailer frame's height. I hope that helps!