johnwynn

Are 30' Diesel Pushers Too Short For A Good Ride?

22 posts in this topic

We are considering a 30' Beaver 2000 but are concerned that they are to light in the front end for a stable, controlled ride. Has anyone had experience with a coach of this length with the diesel engine in the back?

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Johnwynn,

Welcome to the Forum.

We had a 32 foot Monaco Windsor D/P. It road and handled very well. We moved up from a 28 foot gas which handled OK. After the 32 footer we moved up to our present 40 Monaco Dynasty D/P with a tag axle. Each coach was better then the last. I don't think you will have any handling problems with a Beaver. They are very good coaches.

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We have a 32 foot Coachmen diesel pusher for the last 13 years and 120,000 miles. I've done some modifications to the chassis and upgraded engine and transmission. When it was stock it handled well but was lacking in power because it was an early 5.9 cummins.

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Ride and handling are, to a large degree, subjective.

There is one FACT: a longer wheelbase coach with everything else being the same WILL handle better. It may also ride better, if the front axle weight is closer to the GAWR than a shorter coach.

My suggestion is to ask for axle weights from the seller, as most have weighed their coaches- the closer the percents of weight on each axle are to the axle GAWR (i.e.each axle loaded, to say 85% of their GAWR) the better. You don't want the front axle at 75% of GAWR and the rear axle at 95%, as that would likely ride and handle poorer than one that was better balanced.

And more importantly, drive it. A rough road, particularly with a cross wind or 18 wheeler traffic blowing by would be the best test.

Brett

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We have a 32 HR Ambassador and it handled and rode a little rougher than I thought it should. I installed the Source Engineering ride enhancement kit and it rides much better now. It's not a 40 foot tag axle but like Brett says above give it a ride and see if it meets your expectations.

One other addition I intend to complete this year is install a Safe-T-Plus steering stabilizer to improve wind-truck effect and for tracking purposes.

Good Luck I hope you get what you are looking for.

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Remember that you will actually only drive the coach a small percentage of the days that you live in it. Even though we full-time and are forced to move on a regular basis in order to keep up with our business, we only average about 60 days of driving each year. If you are not traveling on business I suspect that your total driving days will be substantially less. So, while you do want the vehicle to be safe to drive, the ride should not be the deciding factor in coach choice. We drive our coach 60 days and we live in our coach 365. What do you think we find more important? Ride or floor plan?

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We have a 37 ft Allegro Bus and also feel not enough power with the 5.9 Cummins.

What did you do to upgrade and how much better is your power?

Everything else is great.

Thanks

TheTexans

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I have driven 40 foot coaches that do not ride as well as my modified 32 footer. As far as engine and transmisson upgrade I installed a ISB 275 and Allison 3060 which is not the fastest up a hill but gives me 11 mpg towing a 1/2 ton silverado.

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Charles10, Before you go to the expense of a different engine you might consider checking out people that have had a Banks Up Grade done to their engine to see what if any difference they got. If they got what you would like it would be a lot less money then a new engine.

Just a thought.

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If the engine is earlier that 1998 its a mechanical injection. The problem with upping the power is that the cooling system is not large enough and it will run hot. Also the intercooler is too small. My transmission was a four speed with no overdrive so the gearing was wrong. That is why I changed engine and trans. I spent a ton of money upping the power and in the end had to make the change.

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We own a 1999 Beaver Monterey 30ft Trinadad. After some front shock work & chassis alignment work, we do not have any ride or handling issues. We just make the forward compartments are not empty and use the top half of the fuel tank. We have owned the coach for four years and are fulltimers for more than two years and have made several trips to the east coast and back on all kinds of road conditions. We used to own a older 40 footer.

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A common problem with handling evaluations is that no one compares the wheelbase with the total length of the coach. A coach that has a wheelbase less than 50% of the total length of the coach is going to be a handful on the road.

I have a 29 foot coach and the wheelbase is about 49% of the length. It wears me out to drive it. A short wheelbase improves manuevering in tight places, but imagine the overhang, both front and rear. Imagine the movement of the tail end of the coach when the the front moves even a few inches. Ruts and wind can cause these seemingly minute movements which result in a wildly moving rear end, all of which requires constant correction to keep it going where you want it to go.

This movement is magnified if you are towing a car. When the tail moves, the car moves, you correct, the tail moves again, the car moves again...you get the picture. Total exhaustion when you finally arrive at your destination.

The longer the wheelbase in comparison to the total length of the coach will provide the best "handling."

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jiffyjet2 is absolutely correct.

Since front overhang is dictated by steering geometry/driver's position and rear overhang is dictated by length of drive shift, transmission, engine and in some cases the CAC and radiator, to turn a 40' coach into a 30' coach, virtually the whole 10' is taken out of the wheelbase. So almost by definition, the shorter the coach, the poorer the WB/OL (Wheel Base to Overall Length).

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Wolfe10 and Jiffyjet2 are on target with their replies. I weigh and analyze all types of RVs , so I have dealt with many concerned drivers about handling issues. One of the components of our analysis program is the wheelbase divided by the total length of the coach. The resulting number should be .54 or above to eliminate design issues that can cause "porpoising". Now that doesn't mean a .54 and above will never experience this problem, if the coach is not loaded properly, or suspension problems may exist causing handling issues to be present regardless of the WB/Length ratio. It also doesn't mean a coach with a .53 or lower ratio will always have issues, it just means there is a possibility that design may contribute to the problem.

This may be valued information, but that wasn't exactly your question. Your concern sounded like it dealt more with the weight of the rear engine diesel on a small wheel base. That would fall under another element of the analysis that deals with the % weight on the front and rear axles. Typically, the front axle should carry between 22%-38%, leaving the remaining 62%-78% on the rear axle. The rear axle will have a rating considerably higher that the front, which should allow the coach to achieve the close percent capacity result Wolfe10 mentioned. As far as I know there is no industry standard on how close the percent capacity should be, but I the closer the better would be good advice.

Beaver and Country Coach both made some outstanding coaches, but I have heard your very complaint from owners of the shorter models.

If ride and safety are major concerns, which they should be, BY ALL MEANS, have the coach weighed and analyzed before you buy it. "Weigh before you pay" is good advice anytime you are considering an RV purchase.

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Texans,

We have two 2002 Dodge 3500s with the 5.9 Cummins. We put a Bully Dog on one that lacked power and it helped a bunch. Could not figure out why one ran better than the other.

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I heard that Beaver tried shortening their 36' Monterey to 32' or 33' while using the same engine. However, the new enhanced power to weight ratio had unintended consequences. Many of these units had handling problems due to a front end that was now too light. One of the attempts to fix the problem was moving the GenSet to the nose of the coach. If that wasn't enough, steel weight was tacked on. This problem was well explained by wolfe10 and halfmoa earlier. So, can a 30' Class A diesel pusher be engineered to handle / ride correctly? Some of the other testimony would certainly indicate so. However, I would do my homework before purchasing one of these shorter units.

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I own a 33' Beaver Patriot 330DP Use it quite frequently and find it handles very well.

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We have a 30ft Beaver Monterry. In more than two years of driving the Beaver It rides great and have no problems with the front too light. We live in Oregon and have long hills and the CAT pushes the hills with ease. Have fun.... BUd & Flo Kemp

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Interesting thread this, how does the arithmetic change with the addition of a Tag. Do you do the calculation using the Tag as the rear axle or the duals in front of it? Does the % weight spread change with a Tag. Is there a length of coach under which a Tag is not beneficial. Look forward to the replies!

Michael Slater

2008 Allure Sunset Bay

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Interesting thread this, how does the arithmetic change with the addition of a Tag. Do you do the calculation using the Tag as the rear axle or the duals in front of it? Does the % weight spread change with a Tag. Is there a length of coach under which a Tag is not beneficial. Look forward to the replies!

Michael Slater

2008 Allure Sunset Bay

Michael,

Yes, the "math" changes. Many use a measurement from front axle to half way between drive and tag for determining "effective wheelbase". I have not seen and hard and fast rule on this, but that measurement makes sense to me as well.

One of the benefits of a well designed tag axle is that it can be adjusted to better balance loads on EACH axle.

At the last Caterpillar RV Engine Owners Club Rally, the Rally "gift" was all wheel position weighing by **** Lorentson of Precision Frame and Alignment. **** and I worked on several tag axle coaches to get proper weight on the tag. The critical issues here are not just weight on tag and drive, but more weight on the tag also shifts more weight to the front axle. Percent of weight on axle should, ideally, be close to the same. Example each axle loaded to 85% of its GAWR. We had one that started at 80, 110, 35. By taking more load on the tag (adjustable air pressure to tag axle air bags) we were able to get it very close to the same percent on each axle. The owner called me two days later and said the coach had never driven so well. Moral of the story, is particularly with a tag axle that is adjustable (not all are/not are easily adjusted) get yours "dialed in" after loading with your gear.

Brett

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Nope! Except in very strong cross winds.

We own a 1992 30' Barth Breakaway with spring suspension. A very enhanced 5.9B (300HP) and converted to an Allison 2000 transmission. Pulling a Suzuki Gran Vitari we get just under 11mpg usually running about 70mph. We average about 12K miles per year as we live in Yuma, AZ and our kids are on the other side of the big hills.

The ride is firm but not uncomfortable and even with the long heavy overhang in the rear it is stable except in strong cross winds. Actually pulling a vehicle helps as it tends to keep the Barth going straight down the road.

We have had MHs since 1978, so we are not new comers to this. I also converted a GM4106 and we also currently own a 43.5' Newell that is for sale.

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