Pier and Surf Forum banner

41 - 47 of 47 Posts

·
Registered
Joined
·
260 Posts
Would someone please explain, in simple terms, the benefits/why going from 20' wheels to 17' wheels helps in the sand. What about the ground clearance that you are loosing?
I read this thread a couple of times, can't grasp the reasoning, yea I'll take the ribbing, what a DA.
 

·
Registered
Joined
·
1,372 Posts
Discussion Starter #42
Bosco: The issue is not with the size of the rim (20" or 17") it is with how much sidewall you loose if you have the same diameter tire (for easy math we will say 30") and how much sidewall deflection aka "ballooning" you lose.

***Note - this is an over simplified example with easy numbers. I am not going into the specifics of sidewall ratios etc....to much math for fishing :D***

If you have the aforementioned 30" diameter tire with a 20" wheel you have a total of 10" of side wall with is then 5" of side wall on either side of the wheel. If you don't know the side wall is the part of the tire between the rim and the part of the tire that touches the ground. If you have the 30" diameter tire with the 17" wheel you now have 13" of side wall or 7.5" per side of the wheel. In this (simple) case the over all min/max clearance does not change since the overall diameter of the tire has not changed. This difference allows for more ballooning which spreads out the pressure over more area, i.e. you float better.

I achieved the same solution but by another route. I got larger sidewall tires on the same size wheel giving me the balloon I was missing with the stock tires, even when aired down. In my case I increased the size of the stock tire diameter from 31" to 35" giving me 2" more ground clearance and also got wider tires 10" to 11.5". All of this lead to a much better ride on the sand. I did go with A/T (all terrain) tires. Theses are slightly aggressive but not M/T (mud terrain). M/Ts have huge knobbies and have a nasty habit of digging in sand badly. Also the "lift" I did on my truck did not do anything to assist in the actual ground clearance, it assisted with tire clearance. The tires added 2" of clearance to the ground but I had to get the wheel wells out of the way to clear the bigger (taller and wider) tires.

I also saw this video posed here a while ago about airing down. Not that you asked about airing down but he talks about the how and why the ballooning works.

hope this helps. I know I can get long winded.
 

·
Registered
Joined
·
483 Posts
Does it have the heated rear bumper option some Fords have? That's to keep frost bite off the hands of the people trying to push you out when your stuck during the cold winter months!
 

·
Registered
Joined
·
1,372 Posts
Discussion Starter #45
No, I didn't get that option, but it does have a step to make it easier to get on the tail gate while waiting for the tow truck
 

·
Registered
Joined
·
483 Posts
That's a good one spyderman, Just kidding about fords, I've owned a few myself! You have good since of humor, rare these days I'm afraid!
 

·
Registered
Joined
·
601 Posts
I think the 20's will be fine if you go up from 55's to 60 or 65's. I have a 2014 RAM 1500 (not putting Fords down). I've aired down to 18psi and haven't had an issue with my 20's (275/60/20). Not sure how much space you have but you may need to get a leveling kit or lift to go up to 65's. Sounds like you will have that covered.

The issue I am having with my 20's are the size tires that I really want require at 20x8.5 rims and up and mine are 20x8. I think I'm going to level the front to 2.8 and go with a 285/60/20. That should give me an inch plus the 2.8 should give me a little breathing room for the front.

The other issue is these newer full size 1500 trucks are so low up front. The front air dam drags like a mother. Hoping the leveling kit and the slightly taller tire will help.
 
41 - 47 of 47 Posts
Top