Poor mans drop case:
With so many people installing longer deep lug tracks for the mountains these days. It brings up the
question of dropping the chain case. Doing a drop is a little too involved for the average sledder, but the
benefits of the increased track angle is hard to argue with in the deep snow. A little known trick that can
be done almost anytime a longer track is installed is to "setback" the rear suspension. With the many
different length tracks these days it has made for several different length rail extensions on the market.
I have found that a guy that is going to use
a 156 track up from a 136 can use extensions for a 151 conversion and then move the suspension back 2.5 inches to make up the difference. Doing so
decreases the approach angle of the track and helps the sled have a better deep snow floatation. All that
needs to be done is a little simple math. Decide on what track you want and then buy the corresponding rail extension you
need.
(chart below)
Next you must do some measuring from existing mounting bolts. the
measurements are simply mapped out and new holes are drilled in the tunnel or the suspension mounting brackets can often be moved by drilling out the rivets and re-installing the bracket in a slightly different location. I have found by doing this on
some Polaris Indy's , that I can take the rear brackets off by drilling out the rivets and then reverse the brackets to give me my setback, then the brackets can be re-riveted back on using the
existing holes. On the front of some Indy's I have found I can drill out the rivet directly behind the mounting hole and
use that spot to mount my suspension. If time is taken to thoroughly inspect the mounts and decide on the
best way to re-mount the brackets using the least amount of drilling necessary
you can have a clean looking installation. I recommend using "buck rivets" if possible. If not, I use button head
Allen bolts. This is also clean looking. If you decide to take the time to do this customization to your sled it will help in deep snow floatation and aid in getting you higher up the hill than ever before.
Shmo
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| Existing
Rails (in) |
New
Track (in) |
Extensions
Used (in) |
Setback
(in) |
| 133 |
141 |
133-136 |
2.5 |
| 133 |
136 |
none |
1.5 |
| 136 |
141 |
none |
2.5 |
| 136 |
144 |
136-141 |
1.5 |
| 136 |
151 |
136-144 |
3.5 |
| 136 |
156 |
136-151 |
2.5 |
| 144 |
151 |
133-136 |
2 |
| 144 |
156 |
144-151 |
2.5 |
| 151 |
156 |
none |
2.5 |
|
