Deflating Tires for Unimproved Roads

[pdemarest]

Hi Blue - By "usual" psi I was relying on the Chinook Owners Manual. In the FAQ section it recommends that the tires be inflated to 65 psi front and 60 psi rears but also says that "some suggest running 55 psi" but doesn't specify if that's for all 6 tires or ??. My Premier was optioned out with almost everything you'd find in a Concourse so I'm assuming that the dry weight is about the same at 9100 lbs. So, I think I'm safe running at 55/50 lbs. but I will get my rig weighed so I can be sure.

[Blue~Go]

Okay, I see. But, yeah, I wouldn't go by Chinook's manual. Reason is that they have to guess at what weights you will be running, but you can know them precisely and so go by the tire mfgr's recommendations. And... maybe they just said that because it sounded safe (I mean, they are decent RV builders but they aren't tire people specifically).

BG

PS: Of course "tire people" aren't always tire people either, or else my car wouldn't come back to me from [nationally known tire shop] with 55psi in each tire when it should really have only 30....

So yeah, I'm comfortable going by the mfgrs' recommendations for my baseline.

[pdemarest]

I know what you mean by "tire people". Years ago I had a bought a set of tires at Sears and they installed them. The next day my front wheel came off at 60 mph. Luckily I was able to get to the shoulder of the road without hitting anything. Ever since then I switched to a local shop that actually knows what they're doing.

[Skillet]

Going back to air compressors, what do you think of this: https://www.amazon.com/gp/product/B00VR ... _qh_dp_hza Some Jeep guys were recommending this. I don't know how it falls, spec-wise when compared to the others (lack of understanding).

[pdemarest]

Hey Skillet - looks like its more heavy duty than a lot of the 12 volt compressors. At 120 psi its stronger than most 12 volt units. I went with a 110 volt unit because I plan on using it for things around the house as well but this looks like a nice alternative. My only concern with 12 volt units is that they tend to heat up pretty quickly but not having any direct experience with this one in particular I'd rely on the reviews.

We just finished up a long trip out west and I really enjoyed the ride in my rig running 55 psi in the front and 50 psi in the back. It had minimal affect on handling and the ride was much more comfortable, even when we did some unimproved roads. At the end of the day I have to remind myself that it is a truck, not a limo, but it was much less punishing to the passengers. If I took the same trip again I would have run a little higher psi. for the long stretches of Interstate 80 that run across Nevada and Utah, but in California I-80 is a pot holed, chewed up mess from the Nevada state line all the way to Sacramento. Good luck on your search for the right compressor.

[Blue~Go]

We just finished up a long trip out west and I really enjoyed the ride in my rig running 55 psi in the front and 50 psi in the back. It had minimal affect on handling and the ride was much more comfortable, even when we did some unimproved roads.

That's close to the recommended pressure for the typical weight of a 21-footer. I'm usually at around 3200# front/6800# rear which corresponds to 40psi front/48psi rear for the stock tire size. That's so close to the bottom of the psi range of the chart that I typically run about 48psi front/52psi rear. But unlike you I have never run them higher, so it was interesting to read your thoughts after experimenting with both.

Back on the compressor topic, I still have not decided which one to get. I was pretty much set on the Viair 400p automatic -- and I think that would be a really good one if I were "airing up" and down in the Chinook regularly. But just the other day I found I had a slow leak in one of my tow-car tires, and realized that hmmm, a compressor would have been nice (air machine was of course broken at the one nearby gas station).

I can't see carrying the 400p in the car (biggish bag), so now I'm thinking perhaps the 88p. It looks like it will still handle the Chinook tires if maybe not quite as "pro-like" as the 400. Figure I'll carry the 88p in the car when I'm towing it, because I may be off in the car sans Chinook, but I won't be driving the Chinook without the car. I tend to take the car exploring on back roads so that's another plus for having the compressor in the car. I carry an floor type bicycle tire pump now, which can be used in a pinch.

[pdemarest]

Hey Blue - I'm glad to know that I'm not running the tires at a psi that's too low; I had worried that I might be trading safety for comfort but it sounds like I'm doing okay at 55 front, 50 rear. I think my rig will last a lot longer if I'm not shaking it to pieces and given my tendency to find "interesting" roads it makes sense for me to keep running at my current pressures. The only downside is that now that I'm running at these pressures successfully I would never have to air-down unless I was on an incredibly bad road so I probably won't use my compressor very often. On the other hand I have a slow leak (wheel leak rather than the tire) on my SUV so I'll be using it weekly for that.

[A Rooney]

Blue,
Never thought of the 400p as "too big"...but have Chinook/blogged long enough to appreciate different folks have 'Gasp' different reactions to the same item.I do recall on the other forum that Woody once posted he had the smaller Viar and was satisfied with its performance.(speaking of another venerable chinooker that has frequently different takes on things)Which is to say my guess is downsizing would quite probably serve you here.I see you are now listed as "Senior Member" do you get there after a certain Age? Rooney (who else)

[Blue~Go]

Blue,
Never thought of the 400p as "too big"...but have Chinook/blogged long enough to appreciate different folks have 'Gasp' different reactions to the same item.

Hi Rooney,

It's not that the 400 is too big; but rather that after realizing that it made more sense to carry the compressor in my tow car than in the Chinook, suddenly I had to find a place for it in a car that's already packed with other gear.

The 400p is 10.87″L x 5.83″W x 7.48″H and 10.70 lbs.

The 88p is 9.8″L x 3.2″W x 5.6″H and 4.75 lbs.

Not that big a difference in one of the Chinook lockers; but just try to cram even the 88p into my car!

I'd still likely go for the 400 if I were going to be keeping it exclusively in the Chinook. Rarely find myself sorry for having bought a better tool.

[A Rooney]

blue,
Tho I use the 400p regularly/occasionally,I have never sensed any 'strain' on the tool as it performs.Leads me to think that the smaller unit might just take a moment longer to reach higher pressures.I think your reasoning is sound as to size in relation to car vs Chinook.I think the smaller unit would handle .99 if not 100 of the tasks.The only time I was glad to have the 400 is when I had to help someone with a total flat,they had tried a cheap knockoff and shook their head and then were amazed as I pumped up that puppy in less than a minute.Its a guy showoff thing but I got to put on my Smug guy with The Right Tool look.Rooney