After years of wanting one, prices had finally dropped, my girlfriend wanted a gift idea, and I wound up with a Trailtech Computer. This is the simple model, called the Endurance, which can be found for around $65.

As with most things like this, it seemed that whoever wrote the directions had never actually tried to install the kit following them. Almost nothing I did was anything like what they said to do. On top of the worthless directions, I installed this in intermittent rain while being eaten alive by mosquitoes. Who doesn’t like that?

The kit comes with miscellaneous hardware to install the computer on the handlebars. In some applications that may be the best option but considering that Trailtech sells kits that mount the computer in the center of the handlebars, this location seemed like an obvious choice.

The computer end of the cable is secured to a mounting base by two screws. I removed the screws and separated the base to locate it on the handlebar mount cover.

The case has two mold marks which I center punched and drilled out with a 1/8″ bit. I then centered it onto the handlebar mount cover.

As luck would have it, the mold marks on the mountain base lined up with the ribs inside the handlebar mount cover.

The cable was reattached to the mounting base, the computer was inserted and the handlebar mount cover was screwed back down.

The sensor end of the cable was fed under the front cover and through a hole near the strut.

You can see the hole is almost directly in line with the center of the tire.

I chose to mount the sensor on the left hand side, but either side will work. On my machine, the hole lets the cable come down between the strut and the proportioning valve.

The top of the cable was secured to the handlebars with included zip ties.

Later on, the cable will be added into the plastic sleeve on the left.

The machine was jacked up and the left wheel removed. On my machine, the front lug nuts were 9/16″.

The sensor for the computer is activated by a magnet passing by it. I placed one of the included magnets on the lip of the rim to get an idea where the sensor would need to be mounted.

At the bottom of the strut I marked the hole in the sensor where it should be mounted for the sensor to line up with the magnet on the rim. This hole will be carefully drilled as the cable that activates the front hub is between two fins on this part, which Polaris calls a hubstrut.

I marked the 1/8″ drill bit for depth so as not to drill too far past the right hand rib and to hopefully prevent any damage to the hub wire.

I chose to mount the sensor behind the strut to protect it from damage. The sensor is attached with an included self-tapping screw.

I had to shim the magnet out substantially to get the sensor to be able to pick it up. A stronger magnet would probably work as well and still be inside the rim and protected. I attached the magnet and the shim to the rim with JB Weld.

I cut off the factory zip ties and put the computer cable inside this sleeve. The cable is slightly too long so the slack was looped over and attached high up in the frame.

Additional zip ties were added to the cable along the handlebars.

The computer is programmed for the diameter of the tire in millimeters. You need to sit on your machine and have somebody measure the tire height. With me on it, my front 23″ tires squish down to 21″. 1 inch is 25.4 millimeters. 21×25.4=533.4 You then multiply the height by pi to get the diameter. 533.4×3.14=1674.876 You can save yourself from the math with the only part of the directions that were anywhere close to useful. They suggest a diameter of 1676 for ATVs. That’s more than close enough.

After everything was done, I was packing the extra parts and documentation back into the original box. The computer comes out of the box stuffed inside some thick foam rubber for protection. I decided to make a case for it. I pondered using an Altoids can but didn’t have one on hand so I sourced a small tin from – well, who else would have something like that – my mom. I centered the tin on the foam and traced it with an ink pen. I pondered what to cut the foam with. Ma suggested an electric knife, which worked perfectly and made no mess at all.

Orange cats for the win! Thanks for the help Ma!

These are the steps I took to install a HPD Chain Tensioner on my 2005 Polaris Scrambler.  I’ve had the part laying around since August of 2005 but today finally seemed like the right time to install it and I had my buddy Jay and Dad around to help out, which made it all a lot easier.

Secured, prepped and ready for wrenching

We removed the wheel for easy access and we removed the stock chain guard as per the installation instructions

The stock tab cut easily and cleanly with a Sawzall

I retained the stock hardware just in case

I released the spring from the arm to ease test fitting

Still test fitting, checking the zirk clearance

Marked the holes

Measurements from the sprocket guard

Mine had a score mark that lined up with the bottom of the swing arm

Clearance from the bottom of the swing arm

Clearance between the chain and the zirk

Successfully installed!