I want to replace my 4.80 X 8 tires and rims with 4.80 X 12, from E trailer.com. The problem is, the pilot hole (hub diameter) on the 8" rim is 2.5" but the 12" rim only comes with a 2.84" pilot hole. This raises different opinions, even among the tech help at E trailer. Other websites/forums seem to also have different theories.
I'm thinking that while these hubs don't use studs with tapered lug nuts to center the rim (lug centric), They do use lug bolts with tapered seats which should do the same job. Some tech folks say no, if you use lug bolts you must use the correct size pilot hole so the rims will center properly (hub centric). Since there are a lot of hands-on trailer folks here, I thought I'd see what folks think. I'm leaning towards going for the 12" rims anyhow but if anyone knows of any rim/hub failures from this I'd sure like to hear about it. What some tech folks say is, using lug bolts to center a hub centric rim places more stress on the hubs and lugs.
Hey Norm, definitely not a tech or an engineer - but I'm facing a similar quandary with a trailer rebuild here. The hub centric method would certainly be the stronger option, but personally I believe the lug centric would be plenty fine for trailer applications. Since the trailer axle does no steering or driving it wouldn't be subjected to any forces that would exceed the capacity of the lugs I wouldn't think?
I've seen a company (out of Germany I think) that markets "adapter rings" to take up the difference in the hub/wheel center but the name escapes me at the moment. (Designed for high-end Mercedes, BMW, etc..) Maybe you could have a set made up by a local machinist?
I'm changing out a 5 lug trailer from stamped steel wheels with the lug centric set up to aluminum slot wheels, using the "mag style" lug nuts with a shank and washer. (70's style wheels, original and definitely used but should polish up nicely.) Like you I'm kinda concerned about the lug bolts holding the weight by themselves, but I have a brother who's a machinist so I'm thinking of giving him a call.........
Just an update in case anyone else is looking at the same dilemma. I went ahead and bought the 12" tires and rims with the oversized pilot hole. I also ordered all new lug nuts at the same time. Installed them nearly a year ago and followed the manufacturers recommendation to recheck the lugs frequently for the first few hundred miles. No problems at all. Never found even one lug that had loosened up. Trailer is smooth, no bouncing tires even at freeway speed. Like Mark said, hub centric is probably stronger overall, but I'm confident that mine will hold together just fine.
Some wheels are hard to find. I wanted one for a spare for my Electra trailer since it had the only two wheels in the world like it but I am so glad I got rid of that thing. I was going to get the hubs machined down to use newer wheels but never did it. In all those years I never had a flat.