Barthmobile Portal
Wheelbase ratio%

This topic can be found at:

07-30-2020, 01:06 AM
Wheelbase ratio%
My motorhome is 28' 5" long, wheel base is 158.7", what is my wheelbase ratio%
07-30-2020, 08:47 AM
46.5 % by using your figures .
This website will explain how to come up with the wheelbase
ratio .


Year:: 1986
Model:: Barth Regal
Length:: 25 ft
Engine:: New Chevy 454 HO
Chassis:: P-30
Data Tag Number:: 8606 3339 25FP2
07-30-2020, 09:36 AM
Jim and Tere
Based on the article, that rv would be considered unsafe. Old Blue had a 192" wheelbase and was 336" long giving it a ratio of 57. It drove very nicely. However, IMHO, this is a rather simplistic approach to whether a motor home is safe or not. 28' Barth Breakaways had a rather heavy diesel in the rear and they had a 158" wheelbase. They were difficult to handle because of the weight ratio between the front and rear axles.

Jim and TereJim and Tere

1985 Regal
29' Chevy 454 P32
8411 3172 29FP3B
Gear Vendor 6 Speed Tranny
07-30-2020, 11:28 PM
I have to say I was thinking about this ratio thing (related to the safety issue) before I bought a 1994 30'diesel Breakaway a couple months ago with a ratio under 50%. After talking to various owners of that particular coach (all positive), I took the plunge and bought it. I have to say, I'm not concerned at all at this time regarding the wheel base ratio of this coach. The Breakaway drives really nicely. It handled pretty well in heavy wind on my drive home (a long drive at that!) and didn't really bounce too much like I thought it would. I think part of the reason is because the Breakaway has such a low profile (10.5' height) and it's on a solid chassis. My old coach was 40' pusher with a tag axle (too big at the end of the day for me and my wife) and this one is 30', spring leaf suspension vs air bags. So, I guess it depends on the coach and the engineering behind it. Best to drive it and talk to other owners of the same coach, if you can, to really get a truthful opinion.