I can't really speak to the used tire thing. Generally speaking I don't buy them. If I'm looking for rollingstock for something that will just be moved around the yard, I'll go used. If I'm trying to determine a fitment I like for new wheels and tires, I'll consider used long enough to make the decision then I'm replacing with new. If I'm getting tires for my 4-wheeler, I don't have a problem with "used" takeoffs. If I just need a spare that holds air, I'll buy used. If it's something I'm going to be driving on the road regularly, I buy new.
14’ is too short, I have a 14’ open deck equipment trailer. Theoretically you could fit a truck on there, but you won’t have a good angle to properly tie it down and don’t turn very sharp with the vehicle you’re towing with or you’ll find the bumper of the truck on the trailer. 16’ is, IMHO, minimum, 18’ is much more comfortable. If you’re going to haul anything longer than like a Bronco II that is, I had one of those on the 14’ trailer and that’s about the max comfortable vehicle length on that deck. I currently have an F-150 frame on there (94 regular cab, 8’ box) and the frame hangs a good few feet off the back with the rad support area at the front of the deck.
I'll second this opinion.
IIRC my flatbed is 16' built from an old camper frame. Was built for the purpose of pulling small cars and trucks, or anything smaller yet too big for the 5x9 utility trailer that dad had. At that time I was figuring to be hauling my 68 F-100 and considering getting something like a mid/late 60s Galaxie in the future. Camper frame allowed for a deck that was just large enough for those, but have not had cause to haul either with it yet. After putting a V8 Explorer on a couple years ago, I really wish that I'd gone longer. Yes, it is technically long enough, but a few extra feet in length would have been very much welcome.
Dad also built a similarly sized flatbed, 14-16' IIRC. I recon it is a true flat deck and tilts to remove the breakover angle of the ramps. While mine has drop torsion axles, his is straight leaf sprung axles and tires are level with or just beliw the deck height. . IIRC, the F-100 has been on it, and my '99 and '85 Rangers have definitely been on it. Too short for comfort, and tall enough to make it not fun loading. It would have been nice to be several foot longer. It wasn't built for automotive, but has done it on a few occasions. He primarily built for hauling his tractor and building materials. The tractor with bucket and bush hog is almost exactly the length of the trailer. If he wanted to take along any other acessories (blx blade, disc harrow, grapple, etc) he'd had to make two trips. Something in the 20-24' range probably would have been better IMO and allowed for better positioning for load balancing.
I guess I've got two flat beds. The one dad built is mom's now, but she'll never pull it. I should probably keep it since it is definitely heavy duty enough for the tractor and other heavy stuff. If I ever get to where I'm towing vehicles a bunch, I should probably look at parting with the first one and see about getting a longer car trailer for that kind of work.
Welcome Visitor! Please take a few seconds and 
