Scamp wheels

[BillE]

Has anyone put 14 or even 15 inch wheels on a 13ft Scamp?


BE

[floyd]

Originally Posted by BillE

Has anyone put 14 or even 15 inch wheels on a 13ft Scamp?


BE

There are lots of threads on this subject, but after all the discussion in each case, the question remains....WHY?

[Perry J]

I'm with Floyd, WHY????

I've refurbished many Scamps since I retired 10 years ago.
All had 13" wheels on them.
All of my camping is in Fire safe area up poor Forest service roads and I've never had a problem.

I put over 25000 miles on my 16' Scamp with 13" wheel and never had a problem.

The question remains, why?

[RogerDat]

There was a custom built job for a rock climber, from the frame up. Gorgeous total remodel job inside. That sat waaay up there. But about the only thing original on that was the shell.

Since a 14 or 15 inch tire requires a new axle I would think if you desire to need a step you can get a couple of inches from more down angle. Which does allow one to stuff a larger wheel into the space. Seems like taller would handle worse and be less aerodynamic. I went through this debate and in the end decided stock worked fine for 30 some years guess I'll stick with it.

[honda03842]

We travel extensively on 13 inch wheels for the last 7 years and have never had an issue and we're on the road almost 8 months a year.

[ruscal]

Additional load carrying ability and more air volume for cushion. More diameter for axle clearance and overcoming obstacles. Better looking.
Better floatation in soft soil. Match up with taller vehicle. There's some whys.
Russ

[FJ40Jim]

Is the scamp bolt pattern compatible with any common junkyard cars? Could we get the 4lug wheels off a NissHonYota (4x100mm) or Saab (4x4.25")?

[Bob Miller]

As mentioned above, it's not about finding appropriate wheels, you can buy those from any of the major RV parts houses, such as etrailer.com, it's about wheelwell clearance. Even with a new stock axle, tire clearance with stock wheels isn't all that great.

To increase wheel/tire size will almost assure the need of a new axle with additional "Down Angle" to raise the coach to get the needed clearance.

As far as adding load capacity, the axle already limits that to what the stock wheels/tires can carry, TV height mismatch is corrected with a drop hitch, and "Better Looking"? And not to mentions reduced stability due to a lightweight trailer with a higher center of gravity.

Again, WHY? is a question that the O.P. needs to answer.

[RogerDat]

There have been a couple of people that have replaced the axle with additional down angle in order to install taller rims and tires. Not many. I can only think of two or three cases.

One had a jeep and wanted the trailer high enough to match the jeep ground clearance. Another was a custom built frame and interior for a rock climber who likewise wanted to have extreme ground clearance.

There is a model of trailer where you can't get a stock axle anymore so the axle ends up mounted under frame and they get lifted, most however try using up angle on the new axle to reduce that high water look.

I think Donna D. did a 45 degree down axle which may have allowed larger than stock tires but that was on a 16 ft. which already has 5 bolt rims.

On a Scamp your ground clearance is the edges of the shell which sit lower than the axle so taller tires only yield a small difference if any there. Going up and down grades is when the shell hits, during transition the nose dips or the rear angles down, tires won't help with that. The wheels are just the pivot point for climbing out of a steep grade.

If you want larger tires you have to have the axle spindle lower or the wheel well won't provide the room for the tires without a good chance of rubbing on bumps. Both FG and tire loose in that situation.

To do that you need to mount axle on a taller bracket which might safely give you an inch or so and/or purchase axle with greater down angle which can gain you a few inches. Lot of money to spend in order to reduce the stability and aerodynamics of the trailer.

Also the 4 bolt on 4" center rims are really only used as 13 inch trailer tires and there are not a lot of rim choices. You may find something some place from a car but 4 inch on center means 4 inch "slightly off" simply won't fit.

With a stock suspension and tires in good condition it works really well. Otherwise your going to spend some money and take your chances that it comes out right. Mostly would depend on how good or lucky the person doing the changes is to determine if it works well or is an epic fail.

[Bob Miller]

Ooops, It looks like off-the-shelf 14' & 15" x 4 on 4" may be a little harder to find. Several show up on Google, but, as Roger suggests, rim offset may be a problem.

BUT: Custom wheel makers, Such as Commercial Wheel & Rim in CA, are happy to knock out a set for a few more $$$.

[Timber Wolf]

I have hesitated to post because I did not want to add to thread drift but it looks like the thread went off anyway so here I go piling on. I agonized over the 13” or 14” question when I put a new axle under my 1988 Scamp 16. It had 4 lug hubs & wheels to start with and the new axle was 5 lug so I had to get new wheels anyway. The old tires were not worth moving to new rims and with the new axle I have plenty of clearance for 14” rims/tires. Going to 14” would not have been a lot more money, would not have added a lot of height, and did have some advantages but in the end I just stuck with 13” and am satisfied. The new axle provides a LOT more ground clearance than the old sagging axle did. I have only pulled a 1,000 miles or so with the new axle but the trailer rides fine and I am satisfied with my decision, although I don’t think 14” would have been a wrong one either.

[BillE]

Originally Posted by Bob Miller

As mentioned above, it's not about finding appropriate wheels, you can buy those from any of the major RV parts houses, such as etrailer.com, it's about wheelwell clearance. Even with a new stock axle, tire clearance with stock wheels isn't all that great.

To increase wheel/tire size will almost assure the need of a new axle with additional "Down Angle" to raise the coach to get the needed clearance.

As far as adding load capacity, the axle already limits that to what the stock wheels/tires can carry, TV height mismatch is corrected with a drop hitch, and "Better Looking"? And not to mentions reduced stability due to a lightweight trailer with a higher center of gravity.

Again, WHY? is a question that the O.P. needs to answer.

More air volume and the slightly higher raise of the body. I am concerned about clearance in the wheel well. The 13 ft sits lower to the ground than the 16 ft. I do tow with a jeep wrangler so I wanted to get the body up higher... albeit small..15 in tire dependent on the overall circumference of the tire may only yield 1.0 - 1.5 inch gain in height ..but there again it is the clearance in the wheel well I am concerned with. That is why I asked if anyone has done it.

There seems to be a WHOLE lot of folks that didn't put larger wheels and tires on but want to voice their opinions on the pros and cons of doingit.

I was looking for someone that has real world EXPIERENCE by actually putting larger wheels and tires on. Then those individuals would be knowledgeable with 1st hand information if it works or not. And ultimately help in the decision.

As far as aerodynamics, does anyone actually know the frontal area or Air resistance = constant * velocity squared...can someone tell me what the delta in raising the trailer 1.5 inches or the pressure or mean stress change ..and how it affects areo dynamics.

[RogerDat]

Originally Posted by BillE

More air volume and the slightly higher raise of the body. I am concerned about clearance in the wheel well. The 13 ft sits lower to the ground than the 16 ft. I do tow with a jeep wrangler so I wanted to get the body up higher... albeit small..15 in tire dependent on the overall circumference of the tire may only yield 1.0 - 1.5 inch gain in height ..but there again it is the clearance in the wheel well I am concerned with. That is why I asked if anyone has done it.

There seems to be a WHOLE lot of folks that didn't put larger wheels and tires on but want to voice their opinions on the pros and cons of doingit.

I was looking for someone that has real world EXPIERENCE by actually putting larger wheels and tires on. Then those individuals would be knowledgeable with 1st hand information if it works or not. And ultimately help in the decision.

As far as aerodynamics, does anyone actually know the frontal area or Air resistance = constant * velocity squared...can someone tell me what the delta in raising the trailer 1.5 inches or the pressure or mean stress change ..and how it affects areo dynamics.

First what you have been seeing posted is real world experience. Many decades of experience and an impressive amount of research into options done by those same posters. They also shared with you why they decided not to go that route for you to consider.

You have not said if you are willing to purchase an axle, if your not and you have a 4 bolt hub you already have your answer. Unless you buy custom rims 4 bolt 14 or 15 inch rims with the right offset and bolt spacing are not known to be available. If you did get such rims via special order at the company suggested in one of the posts then the other answer applies, which has consistently been they won't fit in the wheel well given the stock axle down angle.

I would add that as far as I know the 4 bolt hubs fit a smaller spindle than the 5 bolt hubs so switching hubs is probably not an option, someone on the forum may be able to confirm that. Or a quick call to Dexter axle distributor in your area.

That is why you are not hearing from people who have done it without axle replacement. Lack of parts and it won't fit.

Others have pointed out that if you purchase an axle with sufficient down angle to place the axle spindle lower, and the axle has a 5 bolt hub then it can be done and has been done. There is also options for ordering axle with a slightly taller mounting bracket to help give the wheel well clearance to fit the larger tires.

As to the formula you mention, I have seen threads where the aerodynamics of different trailer models look like my worst nightmares about math story problems. Not sure anyone thinks you really wanted it answered. Electrical engineers seem to be plentiful to answer and discuss all sorts of electrical questions with lots of formulas too.

But it's really much easier than that. Riding low it tucks into the slip stream of the TV, the corners that project are all rounded. Also the shell extends below the floor so when riding lower the bottom front acts more like spoiler. Riding higher less wind cut by the TV and where the back wall extends below the floor acts more like a curved "cup" to catch the wind. No one said it doubles your gas mileage or anything, just that reducing the aerodynamics was less desirable to them so they would not recommend it or decided not to.

Sitting higher is less stable, now no one said it was unstable, just less stable as one of the reasons they did not think higher was a better option.

To get the 1.5 inches more tire into the wheel well with enough room not to hit the wheel well (especially on rough terrain) you will have to raise the trailer more than 1.5 inches. Just to get the extra 1.5 inches above the tire the spindle has to move down 1.5 inches, thus the bottom of the tire also adds 1.5 inches. I think a look at the Dexter axle spec. sheets (see #10 axle) would tell you the lift the different angle axles will provide (see dimension H as I recall) Pay attention to load height and shock load travel.

Folks are freely giving you their opinions based on experience and research, and you are free to pursue whatever course you choose. The fact that many of the people that have been there & done that don't think it is worth the hassle should give you a reason to think it over not a reason to complain about not getting the answer you want.

There are several existing threads to be found using the search feature of the forum located in the upper menu bar, suggest using the Google search option. Here is link to one, page two has a jeep with scamp, active member so you might PM them for what they did.

http://www.fiberglassrv.com/forums/f...ics-49911.html

[ruscal]

Bill,
I have some experience related to what you are talking about. I did a wheel swap on our Scamp 16 a few years back.
When we bought the Scamp it had stock 13" wheels and new looking tires. They were from the year 2003 but had virtually no miles on them. Age dictated throwing them away.
The trailer weighs about 2800 pounds ready to camp. The tires were rated 1300 and something load capacity. The right side tire showed considerable squat at max inflation. My trailer must be heavier on curb side. I didn't like the tires being loaded to max. I then investigated other tires that would fit the 13" rims and carry more weight. I found one available tire that was a little higher capacity, but not enough to make me feel comfortable. Bummer!
Then I began to look at specs for 14" tires. I found one that could carry 1764 lbs. in a smaller sized width. They are Kumho 185 R14C
I did a lot of measuring of the wheel openings and frame width etc to determine if that tire would work. As I remember the size I was looking at had a 25.5" diameter, and would fit under the wheel well, but the axle width would put the tire out just enough to cause trouble with the wheel opening at one spot. I figured that to do it right I would need to shorten the axle length by about an inch.
I ordered a new 3500# Flexiride with adjustable down angle via splined shafts. I mounted it to the Scamp frame spaced down 2" by using 2x2x1/4" tube spacers welded to the frame, and bolted to the Flexiride brackets. The axle center was also moved aft about 1" to increase tongue weight. I also have a wrangler, so desired the extra lift.
In doing the mod I increased the load carrying capacity of the tires.
Got rid of the aged rubber.
Replaced a 10 year old rubber torsion axle.
Got perfect ride height.
New brakes.
New wheel bearings.
Fine adjustable ride height.
And it works really well with no ill effects.
having 2" additional height would hurt fuel economy, but I don't have a clue how much. I averaged 13MPG on last years Moab trip. Not too bad for a lifted Jeep with 4.56 gears and big mud and snow tires. Jeeps are shaped like bricks.
Stability differences could not be felt. The rig corners flat even in a drift. I have been in some hairy crosswinds, and you can certainly feel the gusts, but I can't say it was perceivably different than stock. I passed 2 other tt's that were on their sides. (stickies) The highway patrol had closed the highway to all rv's and 2 wheel drive vehicles, but let me pass. I cruised along about 25mph. in 4WD through the blowing snow and sleet with no issues. The little Scamp just followed along with no weirdness. I was very cautious with the brake pedal, as in not using it!
I have been able to access some pretty remote camping spots out in our local desert without worry of ripping the plumbing off the bottom just by doing the 2" lift, and using the proper draw bar to keep the trailer level.
I have never changed the Flexiride from the stock 22.5 degree down setting.
Russ

[RogerDat]

Russ if you don't mind me asking what did the switch over cost, and did you do the work yourself? I think a post of yours was the one I was thinking of in an earlier post I made. Did you post a picture of Jeep and Scamp hooked up?

Jeep - shaped like a brick. That was why I could never convince my wife to purchase one, too "blocky" she said. Tried for three different auto purchases, almost made it with a Liberty almost. Sigh. A Pontiac something or other, Accord, and Escape. The things we do for love.

[ruscal]

Roger,
I don't remember the costs.
The axle was purchased from a Flexiride approved fabricator from Texas. They placed the brackets exactly to my drawing and can make any custom length. I am guessing it was around $500.00. I can't remember if it came with the brakes or whether I got them from Etrailer.com.
The wheels are cast aluminum and came from Etrailer. Their website is nice with good info and prices. The Kumho tires came from Tire rack.
I have Fab and welding skills and a well equipped home shop, so did the work as a fun project. It is always satisfying improving something you use. It was fun learning about solar and putting together a system for the Scamp too.
I think I did post a picture after doing the lift.
People probably worry a little too much about stability with these little trailers. When loaded properly they tow beautifully and rock steady. A 2" lift is a non factor. They have to be good if a Wrangler can tow one!

[RogerDat]

Load balanced right and riding level they do tow nice, real nice. I really considered going to larger tires, mostly for back country camping and cooler running at highway speeds. Did a bunch of checking and figuring and in the end decided to go with totally stock. At times I wish I had gone with 5 bolt hubs (4 bolt brake hubs are not an in-stock part) Maybe in a decade or two when the new axle wears out someone else will do it different.

All I have to say is if I had gone through a blizzard towing the trailer I would probably be a widower. DW would have had kittens right before she had a heart attack.

Paying for the work of measuring for the axle and welding, along with a little fabrication would run a pretty penny if hired done by a shop, but hey what's the point of knowing how and having a shop if you don't use it?

Glad someone that had done it was able to provide details to the OP.

[ruscal]

Originally Posted by RogerDat

Jeep - shaped like a brick. That was why I could never convince my wife to purchase one, too "blocky" she said. Tried for three different auto purchases, almost made it with a Liberty almost. Sigh. A Pontiac something or other, Accord, and Escape. The things we do for love.

Yeah the Wrangler isn't the most appealing grocery getter to the womenfolk! I know a few ladies that enjoy wheeling their jeeps off-road though. My Jeep did double duty as a daily driver for a couple of years, and I have to say that I don't miss driving it on a daily basis now that I have a "practical car" to tool around in. Off road they are truly amazing once set up for that use. They can go some crazy places! Mine is now strictly a toy. It tows the Scamp and plays in the dirt.

[Borrego Dave]

Russ I have to agree with you as to lifting the trailer. I added the 3" lift from Perfect Casita. My axle is fine but I wanted more clearance for the rear. I haven't noticed any difference with handling or mph since I made the change. Who knows, it may be that my SD17 is heavy.

[Jared J]

I did it on my 19'. I went from 185/80/13 to 225/75/15.

I installed a new axle that was supposedly the stock one (except not worn out), and added a 3" high frame rail under the factory one to mount the axle bracket to.

I still had to cut some of the body to clear the tire, but I figured that going into it. I would do it again in a heartbeat.






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