Another nearly-tiny trailer for ideas

[angib]

This fiberglass trailer is available in Britain, the Sprintaway



The body appears to be 10' long, 5' 6" wide and around 5' high - so quite close to the Compact plans on my web site.

Andrew

[beverlyt]

I'm just curious.....

What is the real "perk" at keeping a trailers height down?

Not having towed much, it would seem to me that if you can't see over the back of your 5' high trailer, (while towing) would it make much difference if you were towing something 7" high?

Is it the actual height or the idea of saving weight, etc?
Isn't it the width that makes the most noticeable difference when towing something?

Bev

[mwatters]

I can think of two reasons.

First is reduced drag. If the trailer is extending past the profile of the tow vehicle (either taller or wider) it's gonna drag. If it's the same or less as the tow, it'll drag much less as it'll basically just be drafting behind it.

The second reason to keep height down is so you can roll it into a garage. My garage door only has a 6'10" clearance (fairly typical of garages using 7' doors - you lose some in the trim). Having a real short trailer lets me roll it into my garage for the winter.

For my own interest - I don't need a trailer to be all THAT tall. Around 95% of the time I'm in it I'm either laying down in bed or sitting at a table. If I was going to install a dance floor - I'd worry more about headroom, but I'm not planning on that.

[dgoy]

Mike is very right about the drag.
I own a trailer that is 9.5ft high and 7.5ft. wide, towed behind a 2003 4runner which is quite a bit lower and narrower than the trailer.
To illustrate how much drag this produces, I had put the transmission in neutral while descending a long 8% hill. Would you believe the tow vehicle and trailer actually slowed down? I have tried this experiment a few times and it always does the same thing.

[cracker39]

My current design has the trailer roof 7' 6" at the highest point. My dad pulled a lot of trailers of different sizes and had a "wing" mounted on his truck cap and swears that it reduced the drag. Andrew doesn't seem to think it would help much, and he is an engineer. But, I'm going to try it anyway...can't hurt and might help. Here is my wing idea; http://pg.photos.yahoo.com/ph/cracker39/detail?.dir=6823&.dnm=a07a.jpg&.src=ph. I haven't worked out just how I'll secure it on the cap, probably with straps connected to the cap window frames. It will just fold down onto the cap top when the trailer is set up at the camp site.

[jimqpublic]

I like the idea of approximately 7'6" tall as a design exercise. My garage door opening- and many new garages- is 8'. The door doesn't quite clear that though so 7'6" is a good goal. It is quite possible to make a trailer with full standing height for a person 6' or a bit taller and still have reasonable ground clearance.

In my fantasy world I start producing trailers for the masses to tow behind reasonable vehicles so I like the idea of fitting 6'3" folks. Me on the other hand- I'm 5'9-1/2" so 6'0" will fit me in boots and add a couple inches for "breathing room" for a 6'2" ceiling. (OTOH my daughter is 4 years old and 47" tall already so maybe we should do 7' ceilings) 2" roof section, 1" floor, 2" frame... we get 11" of ground clearance. Plenty good, especially if the rear section steps up for driveway and dip clearance.

On the aerodynamics front- Why not just make the trailer longer, with a more sloping front end. My Subarus' rooflines are right at 60" off the ground so I'd make sure the roof had curved or angled back by that point.

[cracker39]

That height wasn't planned. I wanted standup room inside without having to do a pop-up or lift-up roof section. About 6'-6'2" at the highest point inside, 2.75" floor and chassis, and about 11"=12" ground clearance is where I came up with the height estimate. With a fan dome added, it will raise the overall height by a few more inches. I'll probably keep it in a my "portable" garage (steel and vinyl canopy) where my boat usually stays. The boat has a cover, so it can sit outside.