Z-400 FRAME FIX
(From our June 2003 issue)
It happens with many first-year model ATV’s. The manufacturers, engineers and testers overlook a few potential problems that a new vehicle may have. It’s not until the machine gets into the hands of the general public that these problems surface.
For example, the Raptor’s transmission was weak and needed to be upgraded for its second year of production in 2002. Also, Bombardier and Cannondale had front steering geometry problems that were corrected after a couple of years. Before that, some Polaris quads suffered from chain fitment and tie-rod problems.
The Z-400 is not immune to this phenomenon. Even with it’s overwhelming success, the Z-400 has some issues. The largest number of reports have been about small cracks forming on the frame around the top of the front shock mounts. All three colors of our 400’s have this problem. If you look closely at the backside of the top shock mount near the weld, chances are you will find a small (or large) crack in the paint and rust forming. Problems have also been reported around the rear shock mount and the headstay area.
Sure, if we rode our Z-400’s with all four tires on the ground, this problem would not happen. Even though most of us do not jump our Z-400s out of helicopters on a regular basis, we do come up short or over jump a double on occasion. Unfortunately the QuadSport frame can?t take it.
We have heard reports that some dealers are warranting the problem with replacement frames. However, if Suzuki hasn’t fixed the problem on the new frames, then what?s the use. Having to take your quad down to the frame for repairs more than once will get old in a hurry.
When we called Suzuki to see if they were aware of the problem and asked if it will be fixed in 2004, we were told “Z-400 issues are being corrected in the current production run. Warrenties are being handled on a case-by-case basis”. In the meantime, we have noticed the prices for replacement frames from the dealer have dropped from $1700 to $900 and are now down to $700. So it looks like they are trying to keep all of there new customers somewhat happy.
FIX NUMBER ONE
To fix the most common problem with the front shock mounts, John Arens of Arens Brothers Inc. has come up with a simple bolt-on solution. The patent pending steel brace encapsulates the front frame cross member and upper shock mounting tabs making them one solid unit.
John supplied us with a Finite Element Analasyst image of the steel being stressed under severe loads in this area. The image of the stock frame shows severe stress exactly where the cracks are developing in the center of the weld. Another image shows a frame equipped with the Arens Bros. Frame Brace under the same loads with minimal stress on the steel.
This under $100 fix should solve the cracking or breaking problems for 90 percent of the Z-400 owners out there. By the time you read this, we will have a couple months test time on the product and will do a full report on it in a later issue. However, if you can?t wait that long, the braces are available now.
Before you install an Arens brace, you will want to inspect your shock mounts carefully. If there are no large cracks or any paint chipping in the upper shock mount area, you can install the brace as a preventative tool. However, if there are already cracks starting to develop near the weld or anywhere, you must take the frame to a competent welding shop and have the cracks repaired before installing the clamp. And the clamp should help you avoid future breakage.
FIX NUMBER TWO
More aggressive riders and racers have been reporting larger problems with Z-400 frames. Even with aftermarket suspension, the frames are breaking at both the front and rear shock mounts. In addition, we have had reports of the headstay (where the top of the steering stem mounts) folding in fast and slow-speed rollovers.
To address these problems as well as strengthen the rest of the chassis for eventual abuse, Lonestar Racing offers a complete chassis gusset service. For $600, they will take your frame (after you ship it to them), completely sand blast it and add a number of gussets and strengthening cross tubes to vulnerable areas including the front shock area.
After the welding is finished, they will powdercoat the frame in a color of your choice and ship it back to you. This service will allow your frame to remain ATVA legal for the Pro Production class.
Dirt Wheels test rider Kory Ellis has had this fix on his Z-400 through the winter stadium series and for the first round of the ATVA motocross season and it is holding up perfectly. This service should allow your Suzuki frame to last a few seasons on the racing circuit or a lifetime on the trails. All for a fraction of the price a complete aftermarket chassis.
Arens Brothers:(989) 593-2599