How to Find Idler Hub to Replace Hub/Rotor of Disc Brake System on Boat Trailer

Updated 03/30/2017 | Published 03/29/2017

Question:

I have a shorelander trailer with Disk brakes. The brakes are not operable as they have corroded away from Salt water. My boat is not heavy enough to require trailer brakes so my question is: I want to replace the rotors and calipers with standard boat trailer hubs. The Brake rotors have a raised inner circle where the wheel and tire mount to. How can I find a hub that would fit on the existing spindle and bring the tire out far enough so it sits under the fender?

asked by: Steve

Expert Reply:

If by standard boat trailer hubs you mean electric drum brakes, which are more and more commonly supplied on boat trailers as standard equipment, you will need to know the bearings used in the existing setup. A new hub/drum has to use the same bearings in order to properly fit on the spindles. Electric drum brakes are popular as replacements since they often cost less than hydraulic drums and since they are much easier to install and maintain. If you want to install hydraulic drum brakes you will again need to find a hub/drum that uses the same bearing set as the current hub/rotor.

You may care to refer to the two linked articles on converting trailers to drum brakes. One applies to electric drums and one to hydraulic.

If you want hubs only -without drums- then you will need to find idler hubs that use the same bearings. I linked our main page for all idler hubs. Once you know your inner and outer bearing numbers you can use that information to check for a compatible idler hub. The hub needs to be rated for your axle weight capacity and it needs to have the correct bolt pattern for your wheels. You can click on the filters on the page to select these attributes.

expert reply by: Adam R