Roadmaster RR8R vs. RR8S

[FDchief]

What is the main difference between the R and the S chassis? Is it the frame thickness and strenght, or is it brakes, axles, and frames. Is it worth it to move up to the next motorhome for the S chassis?

What brakes, disk or drum come on the R vs. S? Are they straight air or air boosted hydraulic?

Thanks again to all.

[FDchief]

What is the main difference between the R and the S chassis? Is it the frame thickness and strenght, or is it brakes, axles, and frames. Is it worth it to move up to the next motorhome for the S chassis?

What brakes, disk or drum come on the R vs. S? Are they straight air or air boosted hydraulic?

Thanks again to all.

[ronboc]

Hi Greg/Linda -

Glad to see you're starting from the bottom up (pun intended) in your research.

I'm sure you'll find a lot of detailed information on the Roadmaster chassis website (roadmaster.com) as well as on their video site. IIRC, dealers also have a dvd of the features/benefits of the coaches and chassis from Monaco/Roadmaster.

Thanks!
Ron

[Robin_M]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by FDchief:
What is the main difference between the R and the S chassis? Is it the frame thickness and strenght, or is it brakes, axles, and frames. </div></BLOCKQUOTE>Greg,

I'm only guessing here, but my guess is that these two chassis are very much alike, and that the only significant difference is the accomadation for the rear radiator on the "R" and the side radiator on the "S".

You won't find an answer to your question on the Roadmaster web site. Actually, I'm quite dissapointed by that site. There's a lot of "sales hype" there and not much else - no information about any "differences" between the chassis models or even a spec chart for the various models.

I suspect that Monaco does not really want to publish a lot of chassis-specific information. I'm guessing that their feeling is that they are in the business of selling motorhomes - not chassis.

[FDchief]

Robin, yes I agree that there is not alot of information on the Monaco site, or the Roadmaster chassis site. I did find that there is a difference is thickness of the steel used in the frame, but the strength of the frame is the same at 50,000 psi. This number doesn't change until you get to the high end semi-monocuqe chassis where it jumps to 100,000.

I believe that you also can get an engine brake vs. an eshaust brake. I am sure the brakes are different too. I have browsed this topic on the chassis forum without much luck, I will keep searching.

[MCDDY]

I believe that the RR stands for Raised Rail where the S stands for SemiMonocoque which all Monaco products were the early years. The S chassis can only be found on the Dynasty upward and thier equivalent coaches in the HR, Safari and Beaver lines.
Dave

[Robin_M]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The S chassis can only be found on the Dynasty upward and thier equivalent coaches in the HR, Safari and Beaver lines.
Dave </div></BLOCKQUOTE>I believe that would be the S-Series chassis, as opposed to the RR8S chassis. See here.

[Pusherpilot]

All this info is current if you're buying new. If you're buying used you have to take the year and brand/model into consideration.

Example:
Our 04 HR Imperial is on the RR8S chassis. In the following yrs the Imperial is on the RR10S chassis.

Ron

[pipedream2]

MCDDY
you are correct in your answer Windsor and up was the break and Dynasty and up is now the break for the chassis

[Spur]

I've been trying to find out a little info myself. From what I can find, the S-series is a Semi Monocoque chassis and the RR-series doesn't say anything about Semi Monocoque. Also the S-series is a steel cage and below that is an aluminum cage. I had thought all Monaco products were Semi Monocoque, but maybe not. The pictures on the site look the same.

[FDchief]

Dave, I think you have it figured out, at least it makes since that the RR would stand for raised rail frame. Not sure if this influences handling at all, but I am sure the Semi Monocoue chassis is stiffer providing a more stable platform. We will have to see if some eingineer type chimes in to fill in the blanks.

[Robin_M]

Greg,

Was your original question referring to the "S-Series" chassis (built for Dynasty and above) or the RR8S chassis (only used for the Camelot and Scepter with a side radiator)? In my original reply I was referring to the RR8S, not the S-Series chassis, which others have been referring to in this thread.

IOW, I thought you were asking about the difference between the RR8R and the RR8S, which is the reason I answered the way I did.

[FDchief]

Robin, your right. I was asking about the differences between the RR and the 8S. Didn't know that there was another S chassis in the Roadmaster line up. Chalk up another one to the forum. Now that you mention it, why would they have two different "S" chassis? Is the 8S not a semi-monocoque chassis?

[Robin_M]

Greg,

OK, I've done some research on this and here's the straight scoop, AFAICS...

I was correct in my original answer... The "S" in the RR8S chassis means "side radiator". The RR series all seem fairly similar, to me, except for the number of airbags and the placement of the radiator. According to the Roadmaster Web Site, RR means "raised rail" (as others have said), followed by a number, which is the number of air bags, followed by an "R" or an "S" which designates the position of the radiator. For example, the RR10S is a raised rail chassis for a Camelot with a tag axle (10 air bags) and a side radiator.

That is not to be confused with the S-Series Chassis, used on the Windsor or Dynasty level and above. In the case of these chassis, the "S" stands for "Semi-monocoque", as others have said. The term "monocoque" refers to a construction technique that supports structural load using an object's externial skin, as opposed to using an internal framework (or truss design) that is then covered by a non-load bearing skin. In the case of Monaco chassis, the term "Semi-Monocoque" applies for two reasons. First, only the top part (or body part) of the chassis is built using a monocoque design, and then that is welded to the base chassis (which uses internal frame rails with cross trusses). The other reason is that even in the top section, Monaco does use some bracing trusses, as we can see on their chassis web site. Monaco uses a steel framework in their semi-monocoque upper chassis and then welds it to the base, giving it a "uni-body" effect, and making it much stronger than an aluminum non-semi-monocoque chassis would be that is only bolted on.

A more in-depth explanation, as it applies to Class A motorhomes, can be found here on the Rversonline.org web site.

Hope this clears up the confusion of the "two S's"