ZBroz Front End Upgrade
I stand in the garage, staring at my sled, patiently waiting for new parts to arrive. I know that snow is just around the corner, and once again, I’m going through my annual race against the clock to get my sled back in one piece before first snow. This has become somewhat of a tradition for me.
I ride a Switchback Assault which, out of the crate is configured for an aggressive 50/50 rider. Wide stance, beefy suspension, and comfortable ride, while still being very capable off trail. This sled suited my needs perfectly when I bought it, but the evolution of my riding style and habits forced me to keep my sled evolving as well. Since buying it, I’ve slowly customized components to create a 144” sled that is closer to an RMK than an Assault. Short seat, powder skis, Burandt boards, paddle track, lower gearing, etc. The last piece of the puzzle was a narrowed front end to accommodate my technical riding goals.
I had made a first attempt at this last season by installing a Pro-RMK front end, but learned quickly that these parts could not take the abuse. The final trip of last season ended rather abruptly on a routine jump that destroyed my front suspension, cutting my trip short.
Not a great way to end an already disappointing season, so I decided to take the offseason to do it right. I had already done my homework on aftermarket front ends, so I knew exactly what I wanted. I chose ZBroz for their solid quality and additional ground clearance. I found a reputable Canadian ZBroz dealer and ordered up the parts, and the waiting game began.
While waiting for the parts to arrive, I started to disassemble the remains of my front suspension in preparation. I did a full visual inspection on the front of the sled to make sure everything was in good working order and that there were no cracks in the bulkhead. I also decided it was a good opportunity to get a fresh coat of powder on my spindles while I had the front end broken down.
There isn’t much more exciting to a sled junkie than receiving new sled parts in the mail. I opened the box and did an inventory of the parts to make sure I had everything I needed. If you take on such a project yourself, make sure to stay organized. It’s a good idea to lay out all the parts and organize them to make the installation go as smooth as possible.
The ZBroz a-arm kit came with everything I needed except for rod ends and spherical bearings. It’s also important to note that these arms are designed to fit a Pro RMK ride height, so shortening your stock shocks is recommended, but not necessary. I decided to use my stock shocks and bearings since they were all in decent shape. Since I didn’t have a hydraulic press at home, I brought my old a-arms to a local garage who popped the bearings out easily. To install the bearings into the new a-arms, I used white grease, a ¾ inch deep socket, and a small vice.
The biggest challenge of the install was getting the spherical bearing of the a-arms properly positioned into the spindle. This is difficult to do on a stock part, and is even more difficult with a light powder coating on the spindle. I had learned from previous installs that its easier to place the a-arm into the spindle first before mounting to the sled to give me the leverage that I needed. This required some brute force with a rubber mallet, but it worked perfectly.
[sc name=”VertQuoteBlack” param1=”Tip : It’s a good idea to place metal parts such as bearings into a deep freeze overnight to let them shrink a bit, making them easier to install.” ]
I Installed the lower a-arm/spindle assembly onto the bulkhead first. The pivot shafts that attach the arms to the bulkhead can be reused, but the plastic bushings cannot. Luckily I already had the bushings on hand from the RMK front end (Polaris Part # 5137700).
Next, I installed my sway bar links before mounting my upper a-arms. This gave me much more room to work with. With the lower assembly in place, I mounted the upper a-arm, followed by the shock, before finally moving onto the tie rods.
To remove the old tie-rods, you first must remove the rubber protective boot to get at the inside rod end. This is tricky since there isn’t a lot of room to maneuver tools.
When installing the ends on the new tie rods, I made sure to have about an equal amount of thread on both the inner and outer ends as a starting point. This gave me the adjustment that I will need later. I left the protective boot off to allow me to perform the ski alignment.
[sc name=”VertQuoteBlack” param1=”Tip : One of the rod ends (typically the spindle side) have a reverse thread. They can easily be twisted off if you aren’t careful. Look at the thread on the tie rod end to make sure. The new ZBroz tie rods have a marking on the end with the reverse thread.” ]
After any front end work, it’s always good to check the ski alignment. To do this, I first made sure that the sled was reasonably level, and that the track was in proper alignment with the tunnel. I adjusted the handlebars so that they were as close to centered as possible. I then used a straight edge as a guide to run down along one side of the track, extending out to the skis. I took a measurement from the edge of the guide to the carbide center at two locations (just in front of and just behind the spindle). I made small adjustments to the tie rod ends and remeasured until the toe of the ski was pointing out by approximately 1/16”. Perform the same steps on the opposite side. When done, you should have a ‘toe out’ measurement of 1/8” from ski to ski. The final step was to install the rubber boot back in place.
The end result was a 39” ski stance with a much higher ground clearance and added strength. I will sacrifice some handling and speed on the trail, but will see big improvements in technical terrain when sidehilling or navigating tree zones. I would highly recommend this upgrade to anyone.