Mount Northern Tool Axle On Top Of Springs or Smaller Wheels?

[Jwh92020]

A guy wants me to build him a 5x8 square drop to tow behind his 2023 Honda CRV (150 lb tow capacity). He wants it as light and low as possible. He has a Northern Tool 5x8 trailer. He wants the camper roof no higher than the car's roof - 65", without compromising interior cabin height. The light part I can handle, but the low part is puzzling me. He wants to use 10" wheels and tires. I'm thinking stick with 12", but mount the axle on top of the springs to lower it. This will not be an off roard trailer. It's just for he and his wife to travel coast to coast. Any ideas will be welcomed.

 

[KCStudly]

Need to make sure that will leave room between the axle and bottom of frame rails for up travel. Might have to C-notch and reinforce the frame.

 

[KCStudly]

Bad things happen to spindles and bearings if the axle hits or rides on the frame. High impact shock test levels of hurt.

 

[Jwh92020]

Need to make sure that will leave room between the axle and bottom of frame rails for up travel. Might have to C-notch and reinforce the frame.

I thought about that. I know that there are a lot of pop ups that run 8" and 10" wheels, and even though 12" isn't a huge difference, the lesseser bearing wear seems like a better way to go.

 

[QueticoBill]

I had no problem over slinging axle on my NT 5 x 8.

 

[GTS225-TNT]

He wants the camper roof no higher than the car's roof - 65", without compromising interior cabin height. The light part I can handle, but the low part is puzzling me.

Maybe a two-piece cabin with a roof that can be raised?

Just a thought.....Roger

 

[Jwh92020]

Maybe a two-piece cabin with a roof that can be raised?

Just a thought.....Roger

I'll mention it to him. Thanks

 

[iamroot]

He wants the camper roof no higher than the car's roof - 65", without compromising interior cabin height.

Is this for efficiency and aerodynamics reasons or storage? See Aerodynamics - One Hundred Years of Missed Opportunities

Lets say the goal is to have 5kw of drag at 55mph (just making up numbers here). Lets say rolling resistance is 1kw and aerodynamics is 4kw. With a squaredrop and hard edges and square back, you might be getting 3kw from the back. Let's say instead you make it 25% taller and that increases the remaining aerodynamic drag from 1kw to 1.5kw. You could reduce the back's aerodynamic drag by 0.5kw fairly easily by adding a 2" radius chamfer to all the edges and making the back 4" narrower than the front part. (I'm spitballing the numbers here) So if the goal is "same drag as squaredrop 65 inches tall" making it that height isn't the only answer.

Bad things happen to spindles and bearings if the axle hits or rides on the frame. High impact shock test levels of hurt.

Bump stop.

Maybe a two-piece cabin with a roof that can be raised?

Teardrops & Tiny Travel Trailers w/ Lifting Roofs on 1st pg

Last updated12/31/2023: To help those who might be thinking of building a lifting roof, here is a list of all the TTT’s with lifting roofs which I (and others...Thanks!) could find. (These camping trailers are not listed in any particular order.) Mike (Myoung)'s Where or When Jr...

www.tnttt.com

 

[Jwh92020]

Is this for efficiency and aerodynamics reasons or storage? See Aerodynamics - One Hundred Years of Missed Opportunities

Lets say the goal is to have 5kw of drag at 55mph (just making up numbers here). Lets say rolling resistance is 1kw and aerodynamics is 4kw. With a squaredrop and hard edges and square back, you might be getting 3kw from the back. Let's say instead you make it 25% taller and that increases the remaining aerodynamic drag from 1kw to 1.5kw. You could reduce the back's aerodynamic drag by 0.5kw fairly easily by adding a 2" radius chamfer to all the edges and making the back 4" narrower than the front part. (I'm spitballing the numbers here) So if the goal is "same drag as squaredrop 65 inches tall" making it that height isn't the only answer.


Bump stop.

Teardrops & Tiny Travel Trailers w/ Lifting Roofs on 1st pg

Last updated12/31/2023: To help those who might be thinking of building a lifting roof, here is a list of all the TTT’s with lifting roofs which I (and others...Thanks!) could find. (These camping trailers are not listed in any particular order.) Mike (Myoung)'s Where or When Jr...

www.tnttt.com

Actually, I think it's a combination of both. He had an old pop up that had 8" wheels that hevpulled around the country wih "no issues" according to him. He figures 10" wheels would be better than 8". He's holding pretty firm on that idea.

 

[KCStudly]

Bump stops only work if there is room for them and they are only engaged within their ability to decelerate the axle at the end of its travel when the springs are already heavily conpressed. If the axle has no travel or is already hard into the stops before the springs are compressed the bumpstop won't do enough work, acting more like a solid hard stop. At least that has been my experience with a lowered vehicle that was loaded down to where there wasn't enough suspension travel. Bumping along on the bump stops felt very much like the axle slamming into the frame rails, and that was at very low speed.

 

[Wandering Sagebrush]

Have you considered declining the business? 10” wheels for a cross continent trip