How fast can I go with itty bitty wheels?

[Triumph Dave]

Hi!  Long time listener, first time poster.  I bought a 95 Dutchman Duck this summer as my first pop-up.  It is in good shape, but has tiny 8" wheels.  I've had the wheel bearings repacked and just replaced the tires and springs (they were sagging).

My question is, how fast can I go with these wheels.  Most of the interstates around here are 70 or 75.  The tire manufacturer says the tires are rated for high speed, but they say that means 45 MPH.  I took it out Labor Day weekend and stayed at 65 or less and that seemed okay.  Am I being too conservative?

Also, would it be wise to switch to a bigger tire/axle combo?  Thanks, you guys are great!

Dave

[tlhdoc]

Welcome to the world of posting.  Did you check how hot your wheel hubs/tires were when you were towing?  I would contact Dutchman and see what they say.  A PU as new as 1995 should be able to handle highway speeds.  I would check how hot the wheel hubs/tires get when towing at higher speeds and compare it to how hot they get at lower speeds.  As far as putting larger tires on the PU, that is a great idea IF they will fit.  Most of the time there isn't room for larger tires.  Good luck.

[flyfisherman]

Dave - once upon a time (I thought), had a chart for max highway speeds for trailer tires but have no idea where I might have stashed it. Anyway, companies like Discount Tire say 65 mph is max highway speed for bias trailer tires.

http://www.discounttire.com/dtcs/infoTrailerTireFacts.dos

For sure, the smaller the tire, the more it has to rotate to keep-up with the larger tow-vehicle tires; and the faster they rotate the faster they wear out - and the more heat they generate - and the heat that's generated increases the chances of failure from blowout. Also, that heat from hotter, faster rotating tires will transfer to the wheel bearings and the axle. Obviously, there's been a big  move toward larger tires. I should think it would NOT be a great engineering feat to replace those eight inchers with something larger. I think I would start by finding out who manufacturered the axle. For example, is it a Dexter axle? There should be a manufacturer's label on the axle and will require you to get under the trailer and see if you can find it! That label will tell you who manufactured the axle, the model number and it's load capacity. If per chance it is a Dexter, you will find those folks are real good in advising what the options are for whatever axle you have.

Another thing that might be of interest for you; my first popup had 13" tires (which I sold and then went to a smaller camper which has 12" tires), and I can tell you for sure the 12's wear out faster than the 13 inchers, however, the 12's are cheaper to buy. Always seems to be a trade-off!

Anyway, when I'm traveling down the highway and towing the popup, I think in terms of 65 mph; might very well pick-up a little speed going downhill to crest the next hill (maybe getting to 70), but I try to think and maintain 65 mph.


Fly

[AustinBoston]

I'm with tlhdoc on this one.  You should be able to go highway speeds, but it is important to see how hot things are getting.  Whenever I stop, I put the back of my hand on the tire (it will feel quite warm, but cool enough to leave the hand there) and on the hub (same thing - quite warm, but not hot enough that you have to take your hand off).

It is also important to keep the tire pressure up.  Don't ever trust the gague on a hose, buy a quality pressure gauge, and check it when the tire is cold.  Pressure rises as the tire heats up, so checking it after several miles of driving will actually result in an underinflated (and dangerous) tire.

Austin

[Triumph Dave]

I did check my hubs as I was driving and they were quite warm; almost hot, but I could leave my hand there.  It was Houston in August.  

I will check with the manufuacturer of the axle to see if an upgrade is possible.  I believe there is room to go to a 12", but I would have to fit check it to see.  I saw another Dutchman for sale that had 12" tires on it.  It appeared to be a similar camper to what I have, but was larger and probably had a larger axle.  If I did upgrade, I would switch to a 3,500 lbs axle vice the 2,500 lbs axle that is on there now.

Thanks for the great advice!  I love my "new" pop-up; should have done this years ago.

[mlslocks]

Why do you need to change the axle?

[Triumph Dave]

My axle has a four lug hub.  The guy at the trailer shop told me that all 10-12" wheels require five lug hubs.

The other reason is:  I noticed excessive wear on the inside of the tire.  Turns out it's a bent axle.  I think one of the springs broke at one point and bent the axle.  New springs brought it more in line, but it probably should be replaced eventually.  I figured, why not put the bigger 5-lug axle on and some 12' wheels to improve the ride!

[flyfisherman]

My axle has a four lug hub.  The guy at the trailer shop told me that all 10-12" wheels require five lug hubs.

The other reason is:  I noticed excessive wear on the inside of the tire.  Turns out it's a bent axle.  I think one of the springs broke at one point and bent the axle.  New springs brought it more in line, but it probably should be replaced eventually.  I figured, why not put the bigger 5-lug axle on and some 12' wheels to improve the ride!

Dave - my 12" wheels on my popup are the four bolt hubs - so I don't think the guy at the trailer shop had all his facts together.

As for the bent axle ... are you sure it's bent?
Sometimes ... please note I said "sometimes" ... the wearing of the inside of the tire is an indicator of trailer overloading - but it is usually on both tires. If the axle is indeed bent, that could also have been caused by someone trying to jack-up the camper at the axle instead of using the camper's main frame rail.

I have a gazillion miles on my camper ... 12" tires and four lug bolt wheels and all. Back when I had half a gazillion miles, one of the leaf springs broke while I was tooling down the highway. Now, the camper was not over-loaded according to what was the camper's specified GVWR (the total weight the camper can carry), I know, because I had the camper weighed. But I replaced the O.E.M. springs with a heavier duty spring, and as you were indicating, with the heavier springs the camper really does go down the road smoother. But my point is that breaking a spring does not necessarily result in a bent axle. I've since been through two sets of tires and they are wearing as even as they did in the beginning when the camper was new. One other point - regardless of whatever load limit the axle may have, you cannot exceed the maximum capacity of the tires. For example, the 12" tires on my camper are rated for a maximum carrying capacity of 1,045 lbs each - so that means the capacity of the tires is 2,090 lbs.. True, the hitch will bear some of the weight, too; but since the trailer is in constant motion traveling down the road, maybe a pitching road causing some weight shift and who knows what all ... I have a hard fast rule of never exceeding the weight of the tire capacity, just as stands, unhitched.

I checked the N.A.D.A. ratings for the '95 Dutchman and could only find two "Duck" models; one is the M-801 and the other is the M-802. Both show a dry weight rating of 1,098 lbs - of course, you would have to add the weight of all accessories that are presently on the camper. Now, on those new tires you just had installed ... what does it say for their maximum load capacity?  For sure, that is what you are limited to carry; camper, accessories and all cargo.

Again, why don't you find out what brand axle (and model number of same) that's under your camper and we can look at your options.


Fly

[Triumph Dave]

Hi, Fly.  Sorry it took so long to get back to you.  The kindly folks at base housing make me park my trailer in a weedy lot on the back side of the base which is hard to get to.

The axle is a Dexter axle.  I believe it is a 2,000 or 2,500 lbs axle, it was hard to tell through the weeds.  I couldn't get the model number, but it is a 4-lug and has no brakes.  You were right about the Duck M-801 weighing 1,098.  It's GVWR is around 1,500 lbs.  I don't load it down, but it does have A/C which is mounted on the left side of the camper, not center mounted.  I don't think the camper is over-loaded, but I could probably have it weighed.  The tires are B-rated tires which are rated at 715 lbs each.  The reason I thought that the axle was bent is beacuse of the excessive wear on the outside of the tire and when on level ground, the trailer sits on the outside of the left tire while the right tire is normal.  The trailer shop said that the axle could not be aligned and was bent.  New springs brought it more in line.  The trailer shop said that heavier springs were not available for my trailer because of the size of the mounts.

Thanks!

[flyfisherman]

Dave - won't do us much good without the model number of that axle, at best all I could do is speculate what you might have. I should think those folks that put on the new springs at the trailer shop would have known what size and model axle you have - on the invoice, did they list the part number for those new  springs?  For sure, you would'nt have a 2500# axle - that would be an over-kill big time for the size of your trailer; besides, manufacturer's just would'nt go to that additional expense ... in fact, I'd suspect they'd go the other way and under-axle it! Perhaps you do have a 2000# (but I'm even wondering about that) - can you tell me how many leaves there were on the new springs ... two or three?

As it stand s right now with your present tires, the load capacity is 1430 lbs - now, they could have put on a load range "C" tire in place of the "B" they did install and that would meant a max load rate of 910 lbs, boosting the tire  capacity to 1820 lbs.

I thought you had posted first that the tire was wearing on the inside? Perhaps you do have a bent axle, and if that were the case I certainly would'nt install larger new tires and wheels on a bent axle. Maybe you can use the camper just as it is for right now, watching the load weight) and get your wear out of those new tires & springs. Getting camper weighed is an excellent idea!

Wal-Mart carries a line of trailer tries and wheels - I see a lot of 4.80X12 and 5.30X12 tires already mounted on wheels (both four and five lug) and might give you a chance to look them over and maybe get some measurements and ideas for a later replacement of the present eight inchers.


Fly

[Brewster_440]

Hi!  Long time listener, first time poster.  I bought a 95 Dutchman Duck this summer as my first pop-up.  It is in good shape, but has tiny 8" wheels.  I've had the wheel bearings repacked and just replaced the tires and springs (they were sagging).

My question is, how fast can I go with these wheels.  Most of the interstates around here are 70 or 75.  The tire manufacturer says the tires are rated for high speed, but they say that means 45 MPH.  I took it out Labor Day weekend and stayed at 65 or less and that seemed okay.  Am I being too conservative?

Also, would it be wise to switch to a bigger tire/axle combo?  Thanks, you guys are great!

Dave

I have a 1993 Jayco 1006 (i think it's about 1300 pounds). I bought it used, so i bought new tires and wheels. Carlisle Sport Trail 5.30 x 12, load range C. It tows fine at 80-85MPH. I don't even know its behind me. It travels VERY straight.

[mike4947]

A few disjointed thoughts/facts on the issue.
All ST tires are rated for either 60 or 65 mph. Until about 5 years ago the only rating given was "suitable for highway speeds". With the rise of some interstates to 75 mph or more the tire companies after a few lawsuits had to put actual numbers to their speed ratings.
It's possible to have one tire show wear without a bent axle. With the advent of slide outs we started noticing a lot of campers showing one tire wear and blow out on slide sides. The slide adds quite a bit of weight off center and we've found while the total axle weight may be fine weighing each side shows one side to actually be well over weight for that tire.
That over center AC could be putting more strain on that sides tire.
We now recommend side to side weights as well as axle and tongue weights for any RV.
As for tire speed the difference isn't as great as you'd think. A 5.3 X 8 inch tire is (5.3 + 5.3 +8 inches in diameter for) a total diameter of 18.6 inches. A 5.3 X 12 is only 20.4 inches in diameter.
 
Check those dates http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=11 to determine how old your tires really are.
 
Check the thread grooves as well as the sidewalls for spiderweb cracking that's the first sign of dry rot and need of tire replacement.
Replace the spare as well as the ones on the ground. Tire that hang off the back as near as fast or as fast as ones on the ground.
And speaking of dry rot don't forget to change the valve stems when changing tires. Even "all metal high pressure" valve stems have rubber seals that again dry rot as fast as the tires.
 
On the issue of replacement axles, for the price, we always recommend replacing with an axle with brakes. The smaller/lighter the TV the more important brakes become even with low trailer weights.