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Ride Ht.

PostPosted: Fri Jul 06, 2007 3:01 pm
by Weerider
Another newbie question... Is there a preferred or optimum ride height for the trailer frame? The total trailer length will be right at 14'. I plan to use a torsion axle and either 14" or 15" wheels. Don't plan to do any offroading and I don't know how much the whole thing will weigh but expect that it will be about 1200lbs. It's easy enough to figure what to order if I just know the desired ride ht. Of course any opinions and advice will be most appreciated.

Howard

PostPosted: Fri Jul 06, 2007 3:09 pm
by fornesto
It can depend on the tow vehicle to a degree. If you make the trailer too low and are towing with a full size pick up truck, it might pull the tongue up and put the tail down. I'm not sure what you're towing with, but I'd measure the ball height and start there. Remember that the trailer will push down slightly on the ball (tongue weight), but usually not enough to make a real difference. I always shoot for level.

On a related note, you might have noticed that big travel trailers and fifth wheels ride a lot higher than they used to. This is in large part due to the tendency of new trucks, especially 4wds to sit much higer from the factory.

PostPosted: Fri Jul 06, 2007 3:19 pm
by Weerider
fornesto wrote:It can depend on the tow vehicle to a degree. If you make the trailer too low and are towing with a full size pick up truck, it might pull the tongue up and put the tail down. I'm not sure what you're towing with, but I'd measure the ball height and start there. Remember that the trailer will push down slightly on the ball (tongue weight), but usually not enough to make a real difference. I always shoot for level.

On a related note, you might have noticed that big travel trailers and fifth wheels ride a lot higher than they used to. This is in large part due to the tendency of new trucks, especially 4wds to sit much higer from the factory.


The tow vehicle is a full size Chevy 2wd pickup. I will adjust the draw bar to pull level and whatever ride ht I decide on... I just don't know exactly what that ride ht should be.

PostPosted: Fri Jul 06, 2007 4:00 pm
by madjack
WR, that is one for you to decide...a 0* start angle with 26"tall tires will give you about 12"s of clearance and be around 16" to 18" from the top of the bed to the ground...about what a couch is and makes for comfortable "door sitting"...if you want it slammed, then go with an increased start angle or if you want it higher, go with a negative start angle...it's up to you.........
madjack 8)

PostPosted: Fri Jul 06, 2007 4:05 pm
by mikeschn
Howard,

Look at this pic as a starting point. If you use a torsion axle with a 22 deg down start angle, your ride angle will be at 0 degrees. Using 14" wheels, your wheel diameter is 26". That puts the underside of the chassis at 14.25

Image

Now just work your way from the underside of the chassis to the center of the ball!

Then get a new ball mount for the truck! ;)

Mike...

PostPosted: Fri Jul 06, 2007 4:20 pm
by Weerider
Thanks Mike and MJ... that's exactly the kind of info I was looking for. Door sitting sounds good... Guess I'll have to decide on mattress thickness now. Don't really want it slammed as my truck definitely isn't slammed.

Thanks...and I'll be back!

Howard

PostPosted: Fri Jul 06, 2007 4:30 pm
by Alphacarina
Handy chart Mike!

It looks like it's not practically possible to get it too low - Even buying axles with an upward arm start angle, and using low profile 14 or 15 inch tires (my 15's are just 24 inches in diameter) you'll have a ride height in the 12 inch range - I would much prefer it be 8 or 9 inches if possible on mine as my tow vehicle (a compact car) doesn't have any more than that and keeping it as low as possible will give it less wind resistance behind the car

Moral of the story is do everything you can to get it as low as possible . . . . and it will probably still be higher than you'd like

Don

PostPosted: Fri Jul 06, 2007 4:35 pm
by madjack
Ac, you are right...there are lotssa difference in tire heights...we use a 205-70-15, which is 26"s tall...here is a tire height/size calculator to play with http://www.miata.net/garage/tirecalc.html
madjack 8)

PostPosted: Fri Jul 06, 2007 4:40 pm
by mikeschn
Here is that wheelcentercalc spreadsheet if you want to plug in your own numbers...

http://www.mikenchell.com/images/wheelcentercalc.xls

Mike...

Alphacarina wrote:Handy chart Mike!

PostPosted: Fri Jul 06, 2007 7:01 pm
by Alphacarina
madjack wrote:...here is a tire height/size calculator to play with http://www.miata.net/garage/tirecalc.html
madjack 8)
Our old tire calculator has been shared all over the Internet for years and years, Jack - I have 22K+ posts on MiataForum . . . . been a moderator there for 6 or 7 years :)

Don

PostPosted: Fri Jul 06, 2007 7:02 pm
by Alphacarina
mikeschn wrote:Here is that wheelcentercalc spreadsheet if you want to plug in your own numbers...

http://www.mikenchell.com/images/wheelcentercalc.xls

Mike...

Alphacarina wrote:Handy chart Mike!


Don't have the software to open that one Mike

Don

PostPosted: Fri Jul 06, 2007 7:08 pm
by mikeschn
This will open it... and it's FREE!

http://www.openoffice.org/

Mike...

PostPosted: Fri Jul 06, 2007 8:16 pm
by asianflava
Maybe there should be a "Files" section that has links to the various spreadsheets etc. that come in handy when building.

PostPosted: Fri Jul 06, 2007 8:19 pm
by mikeschn
That's a thought...

Mike...

asianflava wrote:Maybe there should be a "Files" section that has links to the various spreadsheets etc. that come in handy when building.

PostPosted: Fri Jul 06, 2007 9:11 pm
by madjack
Alphacarina wrote:
madjack wrote:...here is a tire height/size calculator to play with http://www.miata.net/garage/tirecalc.html
madjack 8)
Our old tire calculator has been shared all over the Internet for years and years, Jack - I have 22K+ posts on MiataForum . . . . been a moderator there for 6 or 7 years :)

Don


...I think, I have posted it here, a coule of thousand times over the last few years..................... 8)