Looking for a Suspension Kit for the 2019 Forest River Cardinal 399FLLE w/ Tandem Axle

Updated 07/08/2026 | Published 06/27/2026

Products Featured in This Question

Roadmaster Comfort Ride Leaf Spring Suspension Kit w/ Shock Absorbers - Tandem 7K Trailer Axles

(213)

$2010.00

Question:

I have a 2019 Forest River Cardinal 399FLLE. The RV is approx. 41’ long with 16’ of overhang from the back tire to the rear of the RV. The stock springs are showing signs of flattening out pictures included. I am getting a lot of tail bounce when traveling down the road. I have added SUMO springs thinking this would help, but it did very little. My question is will the slipper spring/shock kit help with this and should I go with the 7K or 8K version. Last cat scale weight showed 13k on the rear axels. Thanks in advance

asked by: Bruce K

2019 Forest River Cardinal 399FLLE Tandem Axle
(click to enlarge)

Expert Reply:

Thank for the photos and details, happy to help Bruce!

Your leaf springs do look fairly flat, but not damaged. With a 16' rear overhang, some tail bounce is expected since the overhang amplifies suspension movement.

Since the SumoSprings didn't make much difference, I don't think a suspension kit alone will solve the issue. Shocks help control bounce, but if the leaf springs have lost their arch, replacing them will have a bigger impact.

With 13k lbs on the axles, I'd recommend the Roadmaster Comfort Ride Leaf Spring Suspension Kit w/ Shock Absorbers 7K kit # RM-2460-2570, assuming your trailer has 7k lb axles. Moving up to 8k could lead to a stiffer ride.

What do you usually keep in the rear of the RV?

expert reply by: James D

Bruce K.

7/2/2026

It is our bedroom. We camp for a month at a time so mostly clothes. The Rv is set up for a washer and dryer but we chose not to install for the above reasons. Most of our weight is pin weight with some tools and toys. So I am afraid the bounce is causing excessive flex in the middle of the trailer.

James D.

7/2/2026

@BruceK a 16' rear overhang, some tail bounce is unavoidable. The Comfort Ride shocks will help control that movement, but replacing your flattened leaf springs at the same time will make the biggest difference.

Lanny

7/8/2026

@BruceK I purchased the Roadmaster about a year ago and have a 1000 miles or so on them. I have a 2023 Momentum 336M and has about 14K on the axles so went with 7k Roadmaster. Contemplated 8k but that makes it a stiffer ride. I have noticed much less bounce and smoother ride overall. Overall i think the investment was worth it and i did the install myself and had very little issues installing. My lippert suspension was wore (bushings) out so had to do something regardless and this was the right choice for me.