Community Forums

Quincybear · 07-03-2015, 07:46 PM

I don't understand the mechanics of why a diesel pusher rides so smooth other than it has air suspension. Why is that unique to diesels and can a gas rv be improved somehow to ride more like a diesel with a "cushier" air like ride? Appreciate any suggestions or explination from our experts out there. Happy 4th

srh · 07-03-2015, 07:56 PM

Here are a few reasons:
DP's, in general, have IFS - although some gasers may have it too.
DP's have a much heavier chassis and air suspension
DP's, in general, have air brakes w/ABS

I'm sure others will chime in with more reasons. God question, though!

Bucky1320 · 07-03-2015, 07:57 PM

Honestly, my gasser had probably a cushier ride than my DP. Handling wise, weight distribution makes a big difference. I always thought it made more sense to have the engine back where the duals are instead of overloading the single fronts.

Mentor · 07-03-2015, 10:14 PM

my rig has a great ride and we have no complaints but wait a sec, it's a gas pusher, the rear wheels push us forward.
take a look at where the rear axle is placed on a DP,,,,, way further aft to carry all that weight

Steady_Rest · 07-04-2015, 03:33 AM

My old Chev P30 gas chassis has a much cushier ride than my brand new Ford F-53 gas mh chassis. One can thank the universally hated coil spring with air bag front suspension for the smooth ride of the P30. I never made any modifications to the P30 and for me it drove fine. I know there are a ton of complaints about the P30 chassis being difficult to control, but I could drive over 700 miles in a day and not feel fatigued from driving. The P30 had 4 wheel disc brakes but no abs, thankfully I never ran into a situation where abs would have helped. The new F-53 does have abs brakes.
The F-53 drives very well, but I find it a stiffer ride that I will have to acclimate myself to. With that said, many former dp owners have been very pleasantly surprised at how much they like the Ford F-53 gas chassis. I have never driven a dp so my subjective opinion pretains only to the difference between the old vs new gas chassis when it comes to cushy riding qualities.
Due to the back road traveling we prefer, a relatively short (32 ft) gas chassis works best for us. I enjoy driving our mh much more than sitting in it parked. The wife makes me stop at times for a couple days, so she can relax, while I go for walks or pace around our camp site thinking about the next road. If we were interested in a longer and heavier mh I would have to give serious consideration to the dp chassis.

Steve N Sal · 07-04-2015, 03:52 AM

Our Workhorse chassis rides very smooth. Much more so than our previous F53 chassis. A lot has to do with tire pressures and how you distribute the load of the coach.
A company that makes a true air ride for a gas coach is Kelderman. Visit there site kelderman.com they used to have videos on the equipment they sell. You can either tackle the installation yourself or have them install it. It is quite expensive though.

tedgard01 · 07-04-2015, 04:27 AM

Mine drives better than yours..... lol

Coma · 07-04-2015, 05:23 AM

Construction techniques are different for one. We have an RR8 Chassis. Raised rail, 8 outboard air bags and 8 Bilstein shocks. It is a solid front axle but set on an H frame, same on the rear. The subframe isolates the raised rail from the road.

Moxy · 07-04-2015, 05:45 AM

Quote:

Originally Posted by Quincybear

I don't understand the mechanics of why a diesel pusher rides so smooth other than it has air suspension. Why is that unique to diesels and can a gas rv be improved somehow to ride more like a diesel with a "cushier" air like ride? Appreciate any suggestions or explination from our experts out there. Happy 4th

typically longer wheel base, weight, multi air bag suspension, typically larger wheels, you would need to convert to air bags and stretch wheel base add 5000 lbs sprung weight, you could likely get there. but then it would be over weight for gas engine ad drivetrain

Moxy

ahicks · 07-04-2015, 06:36 AM

On a gas rig you have springs in all 4 corners. These are of a set capacity (stiffness) to handle anything you put in the motor home, up to it's weight limits. As weight is added, the coach sits lower and lower, and depending on where the weight is added, it's not hard to imagine how one corner or one end be overloaded causing excessive lean/sagging.

A DP, in it's simplest form, has air bags in each corner, replacing the gasser's springs. These air bags are infinitely adjustable using air pressure, and controlled by ride height sensors (for infinite air bag "stiffness"). Let's say there are one of those controlling each air bag to keep this simple. This allows the coach to maintain a given ride height, empty or full, with air bags (springs) no stiffer than required to maintain ride height.

On windy days, where the wind is coming at you from the side, the ride height sensors will be doing there darndest to keep the coach level as well. Not that big a deal, but a definite bonus. They will be lowering air pressure in the up wind bags, and increasing it in the down wind bags, to minimize body lean

I'm not real sure of a gassers available suspension travel (top to bottom), but the DP's will likely be noticeably more.

Then there's the air brakes, exhaust brake, and maybe the biggest deal, with the engine in back, allowing normal conversation in the cab area under any conditions.

Inthe70s · 07-04-2015, 07:08 AM

I have never owned a DP so my opinion is solely based upon ownership of gas motor homes. Our Aerbus rides incredibly smooth and is very quiet. I'm really surprised since I thought it would be far noisier. I attribute the smoothness/cushiness to the tag axle and rear airbag suspension. It also seems to have a lot of insulation in the engine compartment, dog house, and flooring area. Also we have zero squeaks or rattles as we go down the road which I attribute to the welded metal structure and 1 piece solid Fiberglass roof. About the only time there is noise is if we are pulling a grade and the engine is at higher RPM's but even then, it's not bad and we can still have a conversation, just like in a car or truck. I've read that some MH's are poorly insulated and can be quite noisy. I suppose it's partly based upon the manufacturer as well as engineering.

DreamBelieve · 07-04-2015, 07:23 AM

75% of DP's do not have IFS.

Dtwallace · 07-04-2015, 07:34 AM

Another item I didn't see mentioned is the wheel size and it's effect on cushioning the road shock. A larger wheel will ride much better, not falling into holes, or affected as much by small cracks.

Most gas powered motorhomes don't run the larger 22.5 wheel you find on busses and DP motorhomes. If you've ever taken a trip by Greyhound bus, you'll know what I mean.

mel s · 07-04-2015, 07:55 AM

Quote:

Originally Posted by srh

Here are a few reasons:
DP's, in general, have IFS - although some gasers may have it too.
DP's have a much heavier chassis and air suspension
DP's, in general, have air brakes w/ABS
I'm sure others will chime in with more reasons. God question, though!

srh
What is IFS?
Did mean to say "independent front suspension"?

If so my DP doesn't have it.
BTW, it doesn't have air suspension, or air brakes or an anti-lock braking system (ABS), either.

Mel
'96 Safari