Rise Over Run

Texacon · 10-06-2017, 07:16 PM

New to this forum thought I would just jump in and ask the question. First a little background. Our drive slopes up from the street at a fairly steep angle for about the first 12 feet or so then changes to a manageable slope. When we looked at purchasing our current motorhome, we calculated the initial slope of the drive and measured the rise over run and calculated the slope of the rear end of the motorhomes we were interested in. Our purchase decision was made impart to this value. Now we are down sizing and have interest in the Isata 5 30FW and the Isata 3's. Has anyone any words of wisdom regarding the length of the rear and the generally lower height and how to overcome the challenge of backing up the drive so nothing drags on the blacktop. Thanks in advance.

**Bama Rambler** · 10-06-2017, 07:44 PM

I would be glad to draw it out (if you don't already have it) if I could get the following info;
Wheelbase of the unit --
Length of the overhang --
Height of the lowest point at the rear of the overhang --
Slope of the first section of the drive (I assume the perpendicular roadway is level) --
Length of the first sloped section --
Slope of the second drive section --
Length of the second drive section --

Rise and run is better for the sloped sections.

From there you can figure out if the rear end will drag and then come up with some ideas to prevent that.

kenandterry · 10-06-2017, 07:48 PM

Wow.

Your driveway angle sounds like a driveway entrance that I would not attempt to enter IF it was like a gas station entrance or such. The biggest concern with my motorhome is always trying to judge whether there’s enough clearance NOT to drag bottom of the overhang behind the rear wheels.
Every rig is different.

Good luck unless you can approach your driveway at a severe angle from the side.

Texacon · 10-06-2017, 08:37 PM

I don't have this detail on the Isatas, I can get the driveway measurements, it will take me a little time to get it though. Will get back to you and appreciate your help

**bclemens** · 10-09-2017, 08:06 AM

The 30FW probably has our shortest overhang and there is a pretty step departure angle...all point to good geometry for what you are doing. The proto is at Pomona if you want to get some dimensions on it. otherwise I can try and get a "pdf". I trust real world better though.

Texacon · 10-09-2017, 05:11 PM

bclemens, thanks for offering this detail. I note from your responses from other threads I have read you are a rep for Dynamax and appreciate your candidness. Will 4x4 increase this height?

**bclemens** · 10-10-2017, 09:25 AM

I haven't noticed any difference on the 4X4. Being a rear wheel drive, the back is high anyway. i feel like the whole chassis slopes forward.

letsgorving · 10-10-2017, 09:40 AM

Quote:

Originally Posted by Texacon

bclemens, thanks for offering this detail. I note from your responses from other threads I have read you are a rep for Dynamax and appreciate your candidness. Will 4x4 increase this height?

He is actually the "GM" of Dynamax and always on here answering our questions. Amazing

Whalenss · 10-10-2017, 10:17 AM

Quote:

Originally Posted by letsgorving

He is actually the "GM" of Dynamax and always on here answering our questions. Amazing

[emoji106][emoji2][emoji106]

Texacon · 10-10-2017, 08:04 PM

letsgorving, good to know as I move along the route to deciding, having someone from the corp who is personally involved in this forum will go a long way

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