14 in tires om 16 ft Scamp

[KenEllen]

Would it be possible to replace the existing store supplied 13 inch tires on our 16 ft Scamp with 14 inch tires without modifying the wheel wells or anything else?

[Borrego Dave]

Originally Posted by KenEllen

Would it be possible to replace the existing store supplied 13 inch tires on our 16 ft Scamp with 14 inch tires without modifying the wheel wells or anything else?

Sure, piece of cake, you're only adding 1/2" to the wheel well clearance and your Scamp's axle is "new". Your new rims should be a zero offset. Have to ask though, is there a particular reason you want to change out the 13's?

[Wayne Collins]

Unless you are going for more ground clearance, But, if you want more load capacity you may want to try 185/80R13 tires on the same rims. [assuming the factory tires are still ST175/80R13's as they were on our 2000 Scamp 16ft.]
The C rated 185's will increase to load capacity from 1350 lb to 1480 lb per tire.
...or the axle load from 2700 lb to 2960 lb.
In any case, be sure to get the actual, loaded weight on a good scale then adjust the tire pressure accordingly. Out Scamp weighed about 2800 lb.(1400 lb/tire).
That let us run them at 40 - 45 psi.

[Radar1]

We added 14" tires to our 05 16' Scamp several years ago. I had read posts that indicated trimming of the fiberglass was required, but we were lucky and the 14" tires fit just right. Right now we are running Carlisle D rated 205/75R14 tires which are working fine (and have a 81 MPH speed rating which we never use) but when they are ready we might try the new US built Goodyear Endurance tires.
Our reasons for going with 14" tires were two-fold; 13" tires in the size we prefer are hard to find on the road when traveling, and the 13" tires that came with ours only had 1360 lb capacity, for a total of 2720 lb capacity on a 3500 GVWR trailer. The 14" tires provide either 3520 lb capacity (Load range C) or 4080 lb capacity (load range D).
I understand they are now using load range D tires on Scamps, which better suits the 3500 lb GVWR, but they are still not as plentiful as the ubiquitous 205/75R14 tires, which can usually be replaced at Tractor supply stores or Walmart in a pinch.
Our ground clearance went up an inch with the 14" tires, which helps keep the rear bumper from scraping when going through steep driveway dips.

[gordon2]

Originally Posted by Radar1

We added 14" tires to our 05 16' Scamp several years ago. I had read posts that indicated trimming of the fiberglass was required, but we were lucky and the 14" tires fit just right....

How old is your axle? What happens when the axle ages and the trailer rides lower? Will the tires make contact with the inside of the wheel well, maybe when hitting a bump in the road? What will happen if it does just that at 65 MPH? I’d love to put bigger and better tires on my Scamp but these questions haunt me.

[Radar1]

Gordon, our axle is 12 years old. Plenty of clearance now, and based on AlKo axle specs (ours is an AlKo axle) I don't foresee any clearance issues at full deflection. We probably have at least 60,000 miles on the sets of 14" tires since the first set, which include both the rough top of the world highway on our Alaska trip, and even rougher Louisiana interstates. 😀

[KenEllen]

Radar1 says it much better than I could. A 14 inch just seems to add a larger safety margin. We are comfortable towing at 60-65 mph but for piece of mind would prefer a tire that is not being pushed to it's maximum recommended.

It appears a 14 in tire would work fine with my newer Scamp, but I wanted to tap the wisdom of this great forum to make sure I wasn't going to cause problems I had not anticipated.

[Wayne Collins]

Our ground clearance went up an inch with the 14" tires, which helps keep the rear bumper from scraping when going through steep driveway dips.[/QUOTE]

Think about it. You're talking about the diameter of the rim. When you increase diameter by one inch 13 to 14 you only gain a half inch in radius.
But, you also have to consider the aspect ratio of the tires. So, when you want to know how much more ground clearance you get with the 14 inch wheels, look for the static loaded radius of the tires.

[Radar1]

Originally Posted by Wayne Collins

Think about it. You're talking about the diameter of the rim. When you increase diameter by one inch 13 to 14 you only gain a half inch in radius.
But, you also have to consider the aspect ratio of the tires. So, when you want to know how much more ground clearance you get with the 14 inch wheels, look for the static loaded radius of the tires.

Actually I used the manufacturer's published diameters to determine the new radius and height increase. The 13" tires were 24.02 dia (12.01 radius) and the 14" tires were 26.3 dia (13.15 radius). That would put the centerline of the wheel/axle 1.14" higher than with the 13" tires.

[Wayne Collins]

Originally Posted by Radar1

Actually I used the manufacturer's published diameters to determine the new radius and height increase. The 13" tires were 24.02 dia (12.01 radius) and the 14" tires were 26.3 dia (13.15 radius). That would put the centerline of the wheel/axle 1.14" higher than with the 13" tires.

That is getting closer, but it is the LOADED RADIUS that really counts. It accounts for the tire deflection - the flat spot - where the tire meets the road.
And that can vary depending on the load and air pressure.
Ground clearance is also affected by the attitude of the trailer.... level, or nose up or nose down. Usually the lowest part is the axle.

[Raspy]

Originally Posted by Wayne Collins

That is getting closer, but it is the LOADED RADIUS that really counts. It accounts for the tire deflection - the flat spot - where the tire meets the road.
And that can vary depending on the load and air pressure.
Ground clearance is also affected by the attitude of the trailer.... level, or nose up or nose down. Usually the lowest part is the axle.

Since the 14s are 1.14" bigger in radius and since they have a much higher load capacity, it is safe to assume Radar1 will end up with more than an inch height gain. Both the 13s and the 14s support the same load, but the smaller tires will flatten more under a given load. The aspect ratio means nothing here, the published diameters and the rated load capacities/load ranges, are the factors. Assuming reasonable air pressure.

It seems reasonable to expect about 1.5" increase, but it will be more than 1.14"

Larger tires, that are also easier to find, are big advantage. They are stressed less, easier to get and they tend to roll over rough surfaces better.

[Wayne Collins]

Originally Posted by Raspy

Since the 14s are 1.14" bigger in radius and since they have a much higher load capacity, it is safe to assume Radar1 will end up with more than an inch height gain. Both the 13s and the 14s support the same load, but the smaller tires will flatten more under a given load. The aspect ratio means nothing here, the published diameters and the rated load capacities/load ranges, are the factors. Assuming reasonable air pressure.

It seems reasonable to expect about 1.5" increase, but it will be more than 1.14"

Larger tires, that are also easier to find, are big advantage. They are stressed less, easier to get and they tend to roll over rough surfaces better.

Forget all the figuring and speculation. If you need to know what you have you have to measure it.

[Terry M]

What about 14's on a Scamp 13? An inch more ground clearance might be enough to keep my bike carrier trailer hitch from dragging.

[Radar1]

Originally Posted by Wayne Collins

Forget all the figuring and speculation. If you need to know what you have you have to measure it.

1 3/16" to be exact based on actual measurement.