Rough Ride: Bad Roads or Bad Shocks?

[P&GD]

We own a 2011 42 Phaeton QBH, which we recently bought in FL and drove home to PA. The trip north was uneventful and we've only had a couple of smallish issues with the new coach. We are traveling around the PA, DE, NJ region.

We are a bit perplexed by the rough ride for a coach with less than 3,000 miles. The coach tends to porpoise quite a bit with bumps in the road and we seem to feel every seam. We've had the suspension system looked at by a Spartan Service Center and they expressed that the suspense is operating within specification and the shock appear OK.

We are driving about 5 mph under the speed limit in order to keep the coach under control. Cruise control -- forget it. Between the bridge joints and pavement changes, I'm flipping the control on and off all the time. The passing trucks don't seem to be suffering this badly.

Is this normal? The coach is equipped with Bilstein shocks, which I've understood to be highly regarded. This area of the world could not hold itself out for having the bet roads so the issue may be more of the roads vs. the coach. That's why I'm asking. Would prefer to keep our new coach in one piece.

[deanjeep]

Check your tire air pressure and have your coach weighed. Recommended to have each corner weighed independently with the coach loaded. Refer to the tire manufactures inflation chart to make sure you have the correct air pressure in all you tires. Many people have their tires inflated to the max air pressure which is almost always too high especially on the rear axles. It may not totally solve your problem but if your tires are over inflated, lowering the pressure will improve your ride.

[P&GD]

Thanks for your suggestions. I've gotten the coach weighed and determined that all the tires were overinflated for their relative weights; particularly the rear. Taken some air out of the tires and the ride is vastly improved. Again, thanks for the help.

[bcbounders]

Rik & Melinda,

We have an older coach, but also on the Spartan tag chassis... and for the longest time we thought the roads out West were just HORRENDOUS! Lots of jarring bumps and rough wallowing along, even on the Interstates. That was with the OEM Bilstein shocks. We went the route of ensuring our tires were inflated correctly for our weight - and lowering the pressure did, indeed, improve the ride... just not enough. So we decided to try having Koni shocks installed (on just the front axle) and boy are we glad we did! WHAT A DIFFERENCE! The coach now rides like we always thought it should (Spartan, if you're reading this... STOP with the Bilsteins aleady... they're giving your chassis a bad name!).

Of course, if you're happy with the improvement you've gotten from lowering your tire pressures, that's great! But if there's still a little voice in the back of your head saying "Gee... I thought this coach would ride smoother than this"... get the Konis!! You won't regret it!

[P&GD]

Thanks, John. I've seen a number of posts by folks that highly recommend the Konis vs. the Bilsteins. Other folks have commented that there doesn't seem to be much of a difference. Can you tell me the difference between the two brands? And, if you don't mind me asking, what did it cost you to retro-fit your coach?

[bcbounders]

Originally Posted by P&GD

Thanks, John. I've seen a number of posts by folks that highly recommend the Konis vs. the Bilsteins. Other folks have commented that there doesn't seem to be much of a difference. Can you tell me the difference between the two brands? And, if you don't mind me asking, what did it cost you to retro-fit your coach?

With my model year, the difference between the Konis and the OEM Bilsteins has to do with the valving. With the Bilsteins, rough roads caused extremely harsh jarring and jolting... bad enough that I was always afraid that we were damaging the coach... causing excess stress on everything mounted to the walls, etc. And on wavy roads, the coach seemed to hit a harmonic resonance frequency and "wallow" (not quite the "porpoising" that others have reported, but close), bouncing up and down more than seemed necessary for the conditions.

The Konis we had installed aren't the automatic, fully-adjustable version that some axles can get... our axle weight (14,600#) and model won't accept those. So ours are the manually adjustable model #90-2890, set at the middle setting on our coach. I'm certainly no suspension expert, so I can't tell you HOW the Konis are different... but I can tell you the difference in ride. They seem to be better at damping harsh bumps (like bridge abutments, expansion joints and pot holes) and don't translate the harsh jarring into the coach. But, at the same time, under "normal" conditions, they aren't as mushy as the Bilsteins, so they don't allow the coach to "wallow" on wavy roads. All-in-all, a MUCH better ride. I no longer feel so tense driving down the road, as the coach is much smoother and I'm not worried about the longterm effects of all of the vibration and jarring we used to get.

We tend to travel in mostly the same areas, summering in the Pacific Northwest and snowbirding to the desert southwest. So we drive on many of the same roads each year. With the economy being what it is, road conditions have certainly not improved... but with the Konis, the trip is no longer torture!

We had our shocks installed in January of 2010... so pricing may have changed... but ours cost $220 each for the shocks, then $250 for installation labor.

Hope that helps!

- John

[bcbounders]

Oh... one other thing. I know that Bilstein has since come out with a new shock that supposedly behaves much more like the Konis do. I'm not sure when they started distributing them... nor do I know the part number, but I have heard that they supposedly work just as well as the Konis.

[P&GD]

Many thanks again, John, for your thoughts. It is much appreciated.

[bcbounders]

Originally Posted by P&GD

Many thanks again, John, for your thoughts. It is much appreciated.

No problem. If you think of any other questions/concerns, let me know and I'll do my best to answer them!

Good luck!

[historyljc]

Originally Posted by bcbounders

Rik & Melinda,

We have an older coach, but also on the Spartan tag chassis... and for the longest time we thought the roads out West were just HORRENDOUS! Lots of jarring bumps and rough wallowing along, even on the Interstates. That was with the OEM Bilstein shocks. We went the route of ensuring our tires were inflated correctly for our weight - and lowering the pressure did, indeed, improve the ride... just not enough. So we decided to try having Koni shocks installed (on just the front axle) and boy are we glad we did! WHAT A DIFFERENCE! The coach now rides like we always thought it should (Spartan, if you're reading this... STOP with the Bilsteins aleady... they're giving your chassis a bad name!).

Of course, if you're happy with the improvement you've gotten from lowering your tire pressures, that's great! But if there's still a little voice in the back of your head saying "Gee... I thought this coach would ride smoother than this"... get the Konis!! You won't regret it!

An I thought that the Sachs shocks were giving Freightliner a bad name.

I found the Konis to be a help, but no cure all. They did put a stop to the porpoising of my coach. It would be a big help if the state DOTs would learn how to match up the pavement with the ends of the bridges. It must be real difficult, they don't manage it often.

[Mr_D]

Originally Posted by bcbounders

With my model year, the difference between the Konis and the OEM Bilsteins has to do with the valving. With the Bilsteins, rough roads caused extremely harsh jarring and jolting... bad enough that I was always afraid that we were damaging the coach... causing excess stress on everything mounted to the walls, etc. And on wavy roads, the coach seemed to hit a harmonic resonance frequency and "wallow" (not quite the "porpoising" that others have reported, but close), bouncing up and down more than seemed necessary for the conditions.

The Konis we had installed aren't the automatic, fully-adjustable version that some axles can get... our axle weight (14,600#) and model won't accept those. So ours are the manually adjustable model #90-2890, set at the middle setting on our coach. I'm certainly no suspension expert, so I can't tell you HOW the Konis are different... but I can tell you the difference in ride. They seem to be better at damping harsh bumps (like bridge abutments, expansion joints and pot holes) and don't translate the harsh jarring into the coach. But, at the same time, under "normal" conditions, they aren't as mushy as the Bilsteins, so they don't allow the coach to "wallow" on wavy roads. All-in-all, a MUCH better ride. I no longer feel so tense driving down the road, as the coach is much smoother and I'm not worried about the longterm effects of all of the vibration and jarring we used to get.

We tend to travel in mostly the same areas, summering in the Pacific Northwest and snowbirding to the desert southwest. So we drive on many of the same roads each year. With the economy being what it is, road conditions have certainly not improved... but with the Konis, the trip is no longer torture!

We had our shocks installed in January of 2010... so pricing may have changed... but ours cost $220 each for the shocks, then $250 for installation labor.

Hope that helps!

- John

I have the same front axle and shocks. Mine are set to the softest position. I paid $150 each and installed them myself. I also put FSD's on the rear.

[Mr_D]

Originally Posted by historyljc

It would be a big help if the state DOTs would learn how to match up the pavement with the ends of the bridges. It must be real difficult, they don't manage it often.

Actually it is VERY hard as the fill at the bride ends settles over time no matter how hard we tried to get the compaction right.
Yes, 30 years with the WA DOT as an engineer and IT manager.