Double axle vs single axle

[bobblangley]

I am wondering which tows better. Single axle trailers are likely to be lighter whereas double axle trails would seem to offer better weight distribution.

The reason that I ask is that I'm towing a Bigfoot 17 with a Chevrolet 2500HD diesel truck; generally, I can hardly tell that the trailer is there but I do notice the presence of the trailer in an annoying way whenever I go over a bump or other undulation in the road.

So, I wonder which would tow better -- a 21' Bigfoot that weighs 3500# dry and has 2 axles or my 17' Bigfoot that weighs 2500# dry and has 1 axle.

[thrifty bill]

Check weights in the real world. Those Bigfoot weights appear to be way low. Since you already have the 17 footer, it would be great to have another data point for the weight in the real world thread. So if you get a chance to run it across a scale, great.

Since you have more than adequate tow vehicle, I bet the 21 would tow better and weigh more like 6,500 pounds.


Endless opinions out there already on this subject. If you have ever had a flat tire, dual axle is really nice to have.

[Raspy]

There's a big weight difference in the two trailers you list, but generally speaking a tandem axle trailer steps over bumps better if it has leaf springs with an equalizer, as compared to a single axle leaf spring setup. The wheels can work up and down more with less affect on the trailer body because as one moves up the other can move down without flexing the springs. Tandems are less prone to sway, and in my experience, just seem to track better. They also have twice as many brakes, which I like. Some tandem axle trailers only have brakes on one axle. This means they may not stop as well, but may be less likely to slide sideways while braking hard on a curve if one axle locks it's wheels. Tandem axle trailers tend to drag their rear bumpers less while entering and leaving driveways because there are wheels closer to each end of the trailer. The downside of tandems is a heavier suspension system, more tires, wheel bearings, brakes, springs, shocks, etc. So, in very light and short trailers, tandem axles don't make sense. Also, the wheels wells are much larger on tandem trailers and use up more interior space. That can mean less storage or useable space for the water heater, space heater, batteries or cabinets. So again, the smaller the trailer, the more reason to go with a single axle.

I prefer tandem axles for their better ride, better tracking and better off road use where ground clearance can be an issue. And I tend to buy trailers that are around 20-25'. I also tow with a 4WD full sized truck and like to get off road within reason. So, I have the power and weight to tow the trailer well, and the desire to explore and camp along more remote desert roads. For example: last winter we went to Yosemite and it was closed because of snow on the road. So we went out into the National Forest for the night and waited until it was cleared. We went to see the eclipse in Idaho and went five miles out into the forest on a rocky dirt road where there was no lights or other campers. We also go to Death Valley and it is about 60 miles on a dirt road to get in to where we go. I just air down and putt along enjoying the scenery and avoiding larger rocks. Our Oliver, with tandem axles, will go just about anywhere the truck can pull it, all without dragging it's bumper or jack. I've never used an anti-sway device with it and it just flies along on the highway without any drama. With four wheels braking, it does not push the truck at all during stops.

[bobblangley]

Check weights in the real world. Those Bigfoot weights appear to be way low. Since you already have the 17 footer, it would be great to have another data point for the weight in the real world thread. So if you get a chance to run it across a scale, great.

That's easily done because, here in OR, truck scales are active 24/7 and open to the public.

Weight of the 1994 Bigfoot 17 Gaucho trailer with no fluids and no gear -

Weight with only trailer wheels on the scale = 2500#
Weght with only the tongue on the scales = 350#
Total trailer weight = 2850#

[floyd]

Tandem axles are more sensitive to tongue height and must be level for them act as a unit and equally distribute weight. Tandem axles scuff on corners. The further apart the axles and the tighter the cornering , the more the scuff.
Generally speaking, tandem axles are more stable and less prone to sway when properly leveled and loaded.They also require relatively less tongue weight.


Single axles tend to become more stable as tongue weight is increased and track more accurately.

In my opinion the difference is negligible under 3500 pounds with adequate TVs when properly leveled and loaded.
Still... rather two 3500# axles than one 5000# axle on longer and heavier trailers, but one axle becomes the better choice on short and light trailers.
Probably why that's what you see most often.

[FRED SMAILES]

Hi Robert I'm just wondering what you have for tongue weight and have you tried uping the TW , if so what were your observations.
When your trailer is hooked up does it have a slight nose down attitude?
Just some thoughts.
Fred

[CarlD]

Bob,


The annoyance when going over dips and bumps in the road has nothing to do with the number of axles on the trailer. It will be less with a tandem because of the interaction between the wheels as described above. The issue has to do with rotational inertia. The trailer is moving along nicely and you hit a bump in the road. The whole trailer has to move up to go over the bump, including the tongue. The problem is the tongue lifting also lifts the back of the tow vehicle causing the annoyance. If the trailer rotated when it goes over a bump the back of the tow vehicle would not move up and down. Problem is Newton says it doesn't work that way without external forces acting on it!


Carl

[bobblangley]

I'm just wondering what you have for tongue weight and have you tried uping the TW , if so what were your observations.

Current tongue weight is approx 350# with trailer weight at 2500# and I have not played with it much yet.


When your trailer is hooked up does it have a slight nose down attitude?

Its current attitude appears to be slightly nose up.

[Bruce H]

The way a trailer tows depends mostly on the length of the tongue. The shorter the tongue the worse it tows.

[Telescopist]

I've never used an anti-sway device with it and it just flies along on the highway without any drama. With four wheels braking, it does not push the truck at all during stops.

I read your response with interest. I am about ready to buy a 21 Escape. I'm just now tweaking the build sheet. Escape offers three different hitch configurations:
1. Equalizer Hitch $350.00
2. Equalizer Hitch with Sway Control $475.00
3. E2 - Integrated Sway Control and Weight Distribution Hitch $625.00

As you probably already know, the Escape also has a double axle. Several people I have talked to argue that with a double axle I won't need the E2 setup. Others argue that it works really great for them -- 'and why take a chance'?

My tow vehicle will be a 2018 Highlander XLE. Tow capacity according to Toyota is 5,000#/500#.

Perhaps it would be prudent to error on the side of caution and purchase the E2? I never will attempt to maximize these weight limits BTW. Thanks for any feedback.

[Bruce H]

This may be harsh and there is not much we can do about it but any trailer/tow combo that requires an equalizer hitch and or a stabilizer bar either has a trailer that is improperly designed regarding axle placement or tongue length or the tow vehicle is too light.

[Glenn Baglo]

My buddy tows a 19' Escape with a Highlander and uses a Pro Series WDH for security and comfort. I tow a 17' Escape with a RAV4 and use a Pro Series WDH for the same reasons. I do not have sway bars and haven't experienced sway, as long as the trailer is loaded properly. I weigh the tongue with a Sherline tongue scale to ensure it is within range.
I believe the "Equalizer Hitch" that ETI lists is a Pro Series hitch, not an Equal-i-zer brand hitch. You might want to ask.

[Telescopist]

Originally Posted by Bruce H

This may be harsh and there is not much we can do about it but any trailer/tow combo that requires an equalizer hitch and or a stabilizer bar either has a trailer that is improperly designed regarding axle placement or tongue length or the tow vehicle is too light.

I can deal with "harsh". I'm looking for feedback. And thanks. I have read that an equalizer hitch can provide some *comfort* when it comes to encountering high velocity cross winds and/or 18 wheeler trucks blowing by at 75 mph.

[Mike_L]

I tow both single and tandem axle trailers. Tandem definitely tows better.
In my opinion, the impact on the tug of going over a bump with a trailer depends in large part to the type of hitch used. A simple ball hitch just flexes without transmitting significant impact to the tug. A weight distributing hitch essentially makes the chassis of the tug and trailer a single unit. Impact applied to one is thus felt through both.

[Telescopist]

Originally Posted by Glenn Baglo

My buddy tows a 19' Escape with a Highlander and uses a Pro Series WDH for security and comfort. I tow a 17' Escape with a RAV4 and use a Pro Series WDH for the same reasons. I do not have sway bars and haven't experienced sway, as long as the trailer is loaded properly. I weigh the tongue with a Sherline tongue scale to ensure it is within range.
I believe the "Equalizer Hitch" that ETI lists is a Pro Series hitch, not an Equal-i-zer brand hitch. You might want to ask.

It appears that there quite a few people on the Escape forum that tow with a Highlander without any ill effects. I do plan on buying a Sherline tongue scale.
I'll ask...Thanks.

[Glenn Baglo]

I've towed my single axle 17B a mile, without WDH, to the RV service centre near my home. Every bump in the road causes the rear of the RAV to bounce. I've towed thousands of miles on gravel and washboard, through potholes, with the WDH, and the ride is significantly improved.

I wouldn't drag that 68 lb. WDH out to attach to my vehicle if the ride wasn't significantly better.
It does make the tow and trailer feel like a single unit and helps reduce sway from passing semis and crosswinds.

[Sunrisetrucker]

Originally Posted by Bruce H

This may be harsh and there is not much we can do about it but any trailer/tow combo that requires an equalizer hitch and or a stabilizer bar either has a trailer that is improperly designed regarding axle placement or tongue length or the tow vehicle is too light.

Let me be harsh. You my friend are wrong.

[Raspy]

Originally Posted by Telescopist

Perhaps it would be prudent to error on the side of caution and purchase the E2? I never will attempt to maximize these weight limits BTW. Thanks for any feedback.

There are still a number of variables we don't know, the weight of the trailer will probably creep up to a higher number than you expect and weight distribution could change the stability of the trailer. Emergencies happen that require evasive maneuvers. Recommending the lesser of three options assumes we know more than we do and could endanger you.
So, the prudent recommendation is E2, but you should decide what you think is best. I'm glad to see you trying to do the right thing as far as safety and not just declaring there is no problem and doing nothing. There has been some pretty irresponsible recommendations made here over the years (not in this thread) and you are obviously being careful.

[ShelbyM]

Originally Posted by Bruce H

This may be harsh and there is not much we can do about it but any trailer/tow combo that requires an equalizer hitch and or a stabilizer bar either has a trailer that is improperly designed regarding axle placement or tongue length or the tow vehicle is too light.

[CarlD]

Shelby,
Very appropriate emoji.
Maybe we should put the engine and drive train on the trailer and tow the TV. Oh wait, that's a motor home with a dinghy.