Suzuki and Kawasaki teamed up last year to turn the sport ATV industry upside down. Basing their machines design on the ever-popular 400ex frame, which is known to highly resemble one of the best geometries designed to date, the 250R. Not unlike most first year quads however the LTZ400 and the KFX400 had some minor growing pains. Approximately 90% of the Suzuki frame is machine welded, meaning that a computer controlled welding arm has done the welding. These are easy to spot, as they are a very smooth and consistent bead. However a few select items on the frame were welded by hand. Although these are not all together bad welds their inconsistency makes for stress risers.
After approximately 6 months of release the first couple signs of a frame problem began to surface, initially ruled out as minor defects/flaws or constant abuse. However after several more months the cracking problem grew at an undeniable rate. At one point we were seeing a new crack, break or bend pop up every other day on the forum scene.
The cracks are generally focused around the front upper shock mount right where the channel mounts to the frame, as seen in the pictures above. The break usually starts with a small rusting crack and proceeds to grow until either the tube gives or the weld breaks. Until now the only choices that you had were to wait for the break to happen and pray that your dealer would try and get it replaced under warrantee, or strip the machine down and have it gusseted before the problem ever begins. Thanks to the people at
Arens Brothers Inc., namely John Arens there is something you can do ahead of time to try and stop the inevitable.
Arens saw the problems forming with the frame and decided to attack the largest problem directly. Around March of 2003 they developed an upper shock brace that is designed to distribute the loads placed on the channel and welds back to the surrounding tubing and distribute uneven loads placed on one shock to both. The brace, although fairly simple in concept, has some solid engineering basics supporting it. I will warn you however, the brace is not designed to fix broken frames nor will the cracks that have already began to form stop just from installing this brace. If you are simply looking for an easy to install solution to your worries of a cracked frame then this is the way to go.
John is a notorious stickler for details. His initial release of the brace was stifled by redesigns and alterations in an attempt to fit every LTZ and KFX produced. The frames front upper shock mounts have a tolerance zone that makes this task nearly impossible. But after installing the brace myself I must say that the
Arens Bros. have done their homework. The brace not only installed in about 15 minutes but also required absolutely no alterations on my part. Zinc plating on all the components is an unexpected bonus as I feel paint or powder coating would chip or fleck off after initial installation exposing bare metal and inducing rust. I also felt that using the existing hole in the frame plate was a nice touch. Not causing any alterations to the frame and forcing you to install the brace correctly.
Arens has also informed me that the currect tubular brace design is under a slight redesign. They are raising the tube another 1/8" and eliminating the 1/8" spacer, there by simplifying the installation even more.
The brace is typically shipped via USPS (US Postal Service) and comes enclosed in a hard cardboard tube, which is to say the least “fun” to try and get into. You can possibly request that it be sent to you via another shipping cmopany but i found the post office to be plenty quick enough. The kit includes:
2 – Socket head cap screws, which replaces the upper shock bolts.
2 – Nylon hex nuts, for the cap screws, specifically to deter vibration loose.
2 – 1/8” thick washers, used as spacers to raise the brace over the frame.
2 – Smaller hex bolts, for the brace plate back to the frame.
2 – Hex nuts, for the hex bolts.
2 – Bent plate braces, for vertical loading.
1 – Tubular brace, to spread uneven loads from side to side.
The front plastic was removed for this installation simply to allow a better view of the front frame. I would recommend removing the plastic but it is not completely necessary.
To start with block the frame up on either a jack or some kind of stand. Avoid the A-arms as much as possible, as it will force the shock upwards when you remove the bolt. Remove the bolt from the upper shock mount and set it to the side. There is loctite on the bolt so expect it to give you some resistance. Run the cap screws through the tubular brace and slip the washer on right behind it. Slip the screw threw the mount and shock as shown above. Repeat for the other side. Slip the plate brace over the back of the cap screw on the opposite side of the shock mount. There is only one-way for the plate brace to go on so don’t worry about putting it on backwards. Run the cap screw nut on but DO NOT torque it into place. Now run the hex bolt through the brace and frame, placing the nut on the inside of the frame. Get everything centered up as close as possible and toque all screws and bolts into place. That’s all there is to it. Put your plastic back on if you removed it and go ride.
Now for the bottom line, you want to race MX and you want to know if this is the fix all save all solution. My answer to you would be NO. Racing is a whole different situation and I would say if you are serious to purchase yourself an aftermarket frame or at a minimum gusset your frame. Now for the weekend warriors and after work/school small to medium jumping riders, I would say this is the best route to keep your machine up and running with little to no interruption.
I would like to thank John Arens of
Arens Brother Inc. for supplying the brace that was used in this review and would welcome any of you to email John with any questions you have about the brace. He has been doing this type of thing for years and the way the industry is growing. I expect him to be doing this for a LONG time to come.
