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Tall Tex · 05-16-2017, 06:13 PM

Today I had the 99B3234 50mm shocks put on my 17,000 pound capacity IFS axle replacing the OEM 36mm Bilstien shocks. My primary reason for changing was to reduce rebounding/porpoising characteristic of having inadequate dampening in the suspension. The 2017 Anthem came equipped with 60mm Bilstiens evidentially to improve the dampening. I tried desperately to work with Spartan CS and their parts department to buy the bigger Bilstien part number BE5-C433-MO to no avail. Checking on line, that part number was unavailable also. So I ask Spartan to give me a Koni part number for the 17k axle and they told me that they had no reccomendation. Said that the Koni 902890 adjustable shock used on the earlier coachs was not applicable for the 17k axle. So I contacted Koni CS to see what they would say.
They reccomended the 99B3234 non adjustable because it is their latest technology designed specifically for large coaches with IFS axles. So that is the history leading up to my decision to try these shocks.

I took the coach to a local truck shop that I have worked with for over 30 years that has a service pit. We measured the ride height on all three axles and found them to be exactly as per specifications. Spartan told me that improper ride height would cause rebounding issues. They never admitted that the shocks were an issue. The R and R of the shocks was easy when using a good impact wrench.

The results:

The short 20 mile trip from the shop to my house was all freeway that was mostly very good road surface. There were several opportunities to evaluate the rebound characteristics though. I will categorized the undulations, dips, or expansion joints as light, moderate and severe with respect to rebounding. I will define a rebound cycle as the air springs being compressed causing the chassis to accelerate upwards which uncompresses the air springs and then gravity drives the chassis back down. This up/down cycle is one rebound.

Light- the OEM shocks would go through the event and have an additional rebound cycle afterwards. The Evo shocks had no rebound cycle.

Moderate- the OEM shocks would result in having two or three rebound cycles after the initial suspension event. The Evo shocks had one to one and a half rebound cycles and they were less severe.

Severe- the OEM shocks would have three to five cycles after the event. The Evo shocks had two to two and a half and less severe.

The new shocks did slow the velocity going up and down and the vertical movement was less than the OEM shocks.

In addition, roll control or sway felt more controlled when making abrupt lane changes. Ride quality over rough surfaces did not seam to change.

In summary, the coach now has the ride quality I was expecting when I bought it. It now has the luxury ride and gives back the feel of being more in control.
The $400 expense is well worth the improvement. It is unfortunate that Entegra accepted the chassis from Spartan with such poor ride quality.

Next week I will drive it to Kerrville to EOCA Rally for a longer road test and see if my assessment changes.

Tall Tex · 05-16-2017, 06:16 PM

I forgot to include a photo showing the physical difference of the two shocks.

hogdriver · 05-16-2017, 10:08 PM

Thanks Tex

Getting Koni 99-3234s next week on my 2014 Classic

baddmann · 05-17-2017, 04:32 AM

Good info Tex. I have also wondered about the "soft" front suspension on my 2016. There are times when the bounce/rebound is so pronounced that we hear a loud banging noise.

I look forward to your write up after the long trip. If you are still happy with the Konis I will order and replace them also.

brobox · 05-17-2017, 04:57 AM

Sorry to hear that the 60 mm Bilsteins did not do the job. Nice report, it's a shame that Spartan is still behind times on what shocks will fit the front ends. They were still quoting the 90-2890's when the new Evo's 99's were out and others using them with great success. Front end shops were more up to date than the manufacture of the chassis were.....very strange.

Tall Tex · 05-17-2017, 05:49 AM

Quote:

Originally Posted by baddmann

Good info Tex. I have also wondered about the "soft" front suspension on my 2016. There are times when the bounce/rebound is so pronounced that we hear a loud banging noise.

I look forward to your write up after the long trip. If you are still happy with the Konis I will order and replace them also.

I have experienced that banging noise also. About 8 times over 15,000 miles.

I am curious to see if these shocks eliminate that. I think that noise happens when the shocks reach the end of travel when the chassis is pushed up by the air springs.

brobox · 05-17-2017, 06:42 AM

Quote:

Originally Posted by Tall Tex

I have experienced that banging noise also. About 8 times over 15,000 miles.

I am curious to see if these shocks eliminate that. I think that noise happens when the shocks reach the end of travel when the chassis is pushed up by the air springs.

The banging noise was terrible in my Classis with the smaller Bilsteins. The Koni's eliminated that and that is with the old 90 series shocks I'll bet the new 99's will be even better.

Victory Blue · 05-17-2017, 08:48 AM

Quote:

Originally Posted by brobox

Sorry to hear that the 60 mm Bilsteins did not do the job. Nice report, it's a shame that Spartan is still behind times on what shocks will fit the front ends. They were still quoting the 90-2890's when the new Evo's 99's were out and others using them with great success. Front end shops were more up to date than the manufacture of the chassis were.....very strange.

Chuck,

I don't see where he tested the 60mm Bilsteins (new in 2017); it seems he said he couldn't get them. They're on my 2017 and work fine. I believe they are the equal of the Konis.

757driver · 05-17-2017, 09:17 AM

Spartan specs out and puts on a chassis what a customer (Entegra) orders, such as Entegra chassis's are reported to be the only one putting the external hydraulic filter on. Same with the shocks, Entegra ordered the chassis with the smaller shock up until 2017.

brobox · 05-17-2017, 10:15 AM

Quote:

Originally Posted by Victory Blue

Chuck,

I don't see where he tested the 60mm Bilsteins (new in 2017); it seems he said he couldn't get them. They're on my 2017 and work fine. I believe they are the equal of the Konis.

Thank you, I misunderstood that. Glad the 60mm are doing what they are suppose to.

Mr_D · 05-17-2017, 10:18 AM

I found the EVO 99 shocks to be an improvement on my 20,000# IFS on my Country Coach. I installed them last Sept as I remember and have a few miles on them. They are better than the KONI adjustables I took off.

RubiconTrail · 05-17-2017, 10:52 AM

Not sure if it's the bigger shocks, complete front suspension change, or the K3 chassis, but the 17 CS takes bumps and roller coasters WAY better than the 14 Anthem did. That being said, I feel like the Anthem was easier to steer, required less correction, and cornered better. Not complaining, it isn't bad, but the Anthem was better. Maybe the increased height?

Meh, too many variables...both have been great coaches.

lowejug · 05-17-2017, 12:24 PM

2017 cornerstone is the same height of a classic 14 anthem
Both at 12 "11"
A 14 cornerstone was 13"1"
They shortened the new body style with the awning boxes according to
P.j
These new koni non adjustable 99 b are great..
I had the first versions 2890 and still porpoised with them and also
Was getting he bang on big swells

voltdoc · 05-17-2017, 12:43 PM

Thanks for the assessment, great info. FYI we were at Spartan 3 weeks ago and they (Katie) recommended and installed the 99B3234 Koni's on our Reyco 17000 IFS (2017 Aspire). Immediate noticeable improvement in ride quality.