Originally Posted by Whitewater Worthy Equip
We can do rollers every 24” or just one off the back. If you ever think you might want to get 16’ boat it would be worth jumping to the 7x14’
I would never ever own a raft trailer without a roller on back, so I'm willing to be convinced that all those rollers are worthwhile.
Originally Posted by paor
13 or 14 inch tires, .... Speaking of wheels, what would you all recommend for tire size? Are 13s too small?
Yes, 13" is too small unless you are doing a lot of local-only towing. 14" is minimum. 15" is ideal.
It's physics and geometry.
Let's talk tire sizes.
A common 175-80-R13 trailer tire is 24" in diameter.
205-75-14 is 26.3" in diameter
225-75-15 is 28.4" in diameter
7.00-15LT (light truck) is 29.4" in diameter
235-85-16 is 31.6" in diameter.
High school geometry tells us the circumference of a circle is π*d.
The circumference of the 31.6" tire is 99.27". The 24" tall tire is 75.39"
(99.27/75.39)-1 = 32%
75.39/99.27 = 76%
To roll one mile, the 16" tire will only make 76% the revolutions as the 13" tire. This is huge for your bearings, and also the tire.
If your bearings are good for a million rotations (just pulling a number out of my rear), then a bearing on a trailer with 16" tires will go 32% farther before needing bearing replacement.
Every time a tire flexes (squished on the bottom of the revolution, rebound the rest of the circle) it creates heat. The 16" tire has a lot more surface area to dissipate heat, and it's only making 75% the cycles.
So, back to our tire sizes...
205-75-14 should last 110% the life of the 175-80-13 tire, and makes 91% as many revolutions per mile
225-75-15 is 28.4" in diameter. 118% life, only 85% as many revolutions
7.00-15LT (light truck) is 29.4" in diameter. 123% life span, 82% revolutions
235-85-16 is 31.6" in diameter. 132% life and 75% as fast.
Yes, you're going to pay a bit more for larger rubber and steel, but you also gain weight capacity, lifespan, and peace of mind when you're miles from home. Run far away from those little 13" tires. At least invest in 14" tires, and ideally 15". I think 16" is overkill for a raft-only trailer.
There's also a good argument for using light truck tires instead of trailer tires, but that's probably a better subject for a different thread!