Dutch Star suspension improvement

[pasdad1]

Originally Posted by UMXHAULER

I am glad to hear the 40' is a little smoother. It's funny, because all the YouTube videos by dealers always tout the huge 365 front tires on the 43' and say the bigger the tire, the smoother the ride. This is the exact opposite of what I would expect and not so in any vehicle I have ever owned. I suspect they only have the 365's because they need them for the load capacity and nothing else.

Wouldn’t a 365 at 105 psi ride smoother than a 315 at 130 psi ?

I suspect it does.

[UMXHAULER]

Originally Posted by pasdad1

Wouldn’t a 365 at 105 psi ride smoother than a 315 at 130 psi ?

I suspect it does.

I would not expect that at all. It's related to pounds per square inch on contact pressure with the road. All things being equal, it takes more tire air pressure to properly support the weight in a smaller tire than a larger tire but this does not equate to a rougher ride necessarily. A wider tire may straddle some road imperfections but at the same time it may catch more of those imperfections as well. Think of the tires as just another suspension item. Also, specific tire construction can effect ride as well. Any vehicle I have ever owned where I have installed larger tires always rides rougher even while running lower tire pressures. I don't know the specs of the 365's vs the 315's, but as I said I would think the chassis builder only put on the larger ones because it was necessary to carry the extra load-but they do look cool. BTW, I only run my fronts at 110psi-not 130 based on actual rig weight.

[pasdad1]

Originally Posted by UMXHAULER

I would not expect that at all. It's related to pounds per square inch on contact pressure with the road. All things being equal, it takes more tire air pressure to properly support the weight in a smaller tire than a larger tire but this does not equate to a rougher ride necessarily. A wider tire may straddle some road imperfections but at the same time it may catch more of those imperfections as well. Think of the tires as just another suspension item. Also, specific tire construction can effect ride as well. Any vehicle I have ever owned where I have installed larger tires always rides rougher even while running lower tire pressures. I don't know the specs of the 365's vs the 315's, but as I said I would think the chassis builder only put on the larger ones because it was necessary to carry the extra load-but they do look cool. BTW, I only run my fronts at 110psi-not 130 based on actual rig weight.

It is the sidewall of the tire that acts as the “cushion”. When the tire is inflated to max pressure there is very little “give”…. the bigger tire will flex much more at the lower pressure.

This is why off road folks put large tires and lower the pressure.

[redbaron73]

Originally Posted by pasdad1

It is the sidewall of the tire that acts as the “cushion”. When the tire is inflated to max pressure there is very little “give”…. the bigger tire will flex much more at the lower pressure.

This is why off road folks put large tires and lower the pressure.

Exactly. My dutchstar rode terrible at 125PSI, but lowering to 110PSI made it much smoother.

Charts called for 105 PSI, so I was still 5PSI margin

[UMXHAULER]

"It is the sidewall of the tire that acts as the “cushion”. When the tire is inflated to max pressure there is very little “give”…. the bigger tire will flex much more at the lower pressure.

This is why off road folks put large tires and lower the pressure.
pasdad1 is offline Report Post"

It may in fact be correct that the 365's vs the 315's ride smoother on our big motorhomes, but I was really looking for people with actual experience who have driven both-not a you tube poster or our theoretical back and forth. I have lots of theories with very little proof but some experience in other situations. I agree the side wall acts as a cushion, however, when you have a smaller tire with higher pressure, the sidewall may flex as much as the larger tire with lower pressure because of the higher load over a smaller area-I experience this all the time on dirt bikes and mountain bikes. I am an off-roader as well, and we run extremely low pressures so the tire will flex while going up rocks for example and have better flotation on sand-usually the bigger the tire, the lower the air pressure we need to run to get the same flex. Wider tires will give you better bite/traction on loose surfaces. If you go to larger diameter tire, it will actually cut down your traction on a very steep hill climb. However, if you air those same big tires up for road use, they can be very rough riding and some of that has to do with tread design of course. Anyhow, we have kind of hijacked the OP's original question-sorry about that.

[redbaron73]

Originally Posted by UMXHAULER

"It is the sidewall of the tire that acts as the “cushion”. When the tire is inflated to max pressure there is very little “give”…. the bigger tire will flex much more at the lower pressure.

This is why off road folks put large tires and lower the pressure.
pasdad1 is offline Report Post"

It may in fact be correct that the 365's vs the 315's ride smoother on our big motorhomes, but I was really looking for people with actual experience who have driven both-not a you tube poster or our theoretical back and forth. I have lots of theories with very little proof but some experience in other situations. I agree the side wall acts as a cushion, however, when you have a smaller tire with higher pressure, the sidewall may flex as much as the larger tire with lower pressure because of the higher load over a smaller area-I experience this all the time on dirt bikes and mountain bikes. I am an off-roader as well, and we run extremely low pressures so the tire will flex while going up rocks for example and have better flotation on sand-usually the bigger the tire, the lower the air pressure we need to run to get the same flex. Wider tires will give you better bite/traction on loose surfaces. If you go to larger diameter tire, it will actually cut down your traction on a very steep hill climb. However, if you air those same big tires up for road use, they can be very rough riding and some of that has to do with tread design of course. Anyhow, we have kind of hijacked the OP's original question-sorry about that.

I don't know how much more information you can expect to get. I have had both tire sizes (2013 DSDP on 315's , 2019 on 365's)> Both had very rough ride when over aired, but when aired properly they both where much more comfortable.

There are lots of posts stating the same thing here, but I am giving you my personal experience and verification that the ride is better with less air.

[UMXHAULER]

Thanks Redbaron. I appreciate the reply. I get it that both sizes need to be aired to the proper PSI for the load. Was just wondering if when both are aired properly, do the bigger 365's ride better or worse, but you basically are saying that the coaches still ride very similar.

[redbaron73]

Originally Posted by UMXHAULER

Thanks Redbaron. I appreciate the reply. I get it that both sizes need to be aired to the proper PSI for the load. Was just wondering if when both are aired properly, do the bigger 365's ride better or worse, but you basically are saying that the coaches still ride very similar.

One more important datapoint:

my 2013 weighed 14k lbs on the front axle, and it had a 17k axle. I was 3k under the max weight. The tires being smaller, had less weight on them, so 110PSI was the right air.

my 2019 weighed 17k lbs on the front, so 110psi for the 365's was more than necessary, but still felt very good.

The coach to watch was the 2016 DSDP. It originally came out with a 17k axle and was on 315's. The front end weighed 17k with 1/2 tank fuel. The 315's had to be fully inflated to support the weight. 365's did not fit.

The same coach was built in 2017, but with 365's and a 19k axle. The pressures where at 110psi. Back to back on those 2 coaches gave a very different ride.

Even those that got the recall for the 19k axle on 2016 still had to keep 315's and suffer the harsh ride.

[Vagabond51]

Originally Posted by Dutch Star Don

The Koni's eliminate the front end chop and reduce some of the impact of potholes to the cab.

When I buy a coach, the first thing I do is upgrade the suspension/ride and then worry about upgrading other things like electronics and comfort items.

Hi, so, my 2022 Newmar Dutch Star 4081 (Spartan) has vertical threads versus horizontal threads. Would someone please help me understand what the process is to remove/install these! Included is a picture of the current shocks and what I will replace them with. Do I have to raise the body even higher to clear the bolts/threads or compress the shock? 💪🏼
Thank you!

PS, a video would be very helpful. 😁

[wolfe10]

Originally Posted by Vagabond51

Do I have to raise the body even higher to clear the bolts/threads or compress the shock? ����
Thank you!

With coach at ride height or on jacks, you just compress the shocks. With gas charged Bilsteins, a little more difficult, but doable.


Said another way, at ride height, you will have several inches to be able to compress them, as shock length is generally speced so that at ride height, they are close to mid-travel.


And, as always, when working under a coach, have safety stands in place. Too heavy to "bench press".

[Vagabond51]

Originally Posted by wolfe10

With gas charged Bilsteins, a little more difficult, but doable.

SWEET!

Thank you!

[Vagabond51]

[QUOTE=wolfe10;6372691]With coach at ride height or on jacks, you just compress the shocks. With gas charged Bilsteins, a little more difficult, but doable.

[


Said another way, at ride height, you will have several inches to be able to compress them, as shock length is generally speced so that at ride height, they are close to mid-travel.


And, as always, when working under a coach, have safety stands in place. Too heavy to "bench press".

MISSION ACCOMPLISHED!!! You are correct. The Bilsteins are very difficult. I weigh about 150 and really had to work hard. Really hard. But all-in-all not too bad. Not a one hour job for me, but excited to take ‘er for a spin! I’ll provide feedback on whether it was with the cost, and pain… 😫

Thanks for your help!

[Dutch Star Don]

During your test drive, note the movement of the front shades. With the OEM shocks, they moved (chattered) quite a bit. The EVO's calmed that down. I also found some of the larger potholes were less noticeable.

[Suburbazine]

[QUOTE=Vagabond51;6372859]

Originally Posted by wolfe10

With coach at ride height or on jacks, you just compress the shocks. With gas charged Bilsteins, a little more difficult, but doable.



MISSION ACCOMPLISHED!!! You are correct. The Bilsteins are very difficult. I weigh about 150 and really had to work hard. Really hard. But all-in-all not too bad. Not a one hour job for me, but excited to take ‘er for a spin! I’ll provide feedback on whether it was with the cost, and pain… 😫

Thanks for your help!

So if you ever happen to do this again, it's far, far easier to compress the shock using a jack under the hub. Once you have the shock compressed (it only needs a couple of inches for this to work) you take some 550 cord or a wire spool, tie off the top of the shock and then tie off the bottom. When you unload the jack, the shock will be kept from extending and pull right out of the lower hole (make sure to remove the nut first!).