[BrendanB]

Our team has used shifting gearboxes for all three seasons with two of them being on the kitbot (2012 robot was custom tube frame). Of all three years, this past season was probably the one year we could have gotten away with a single speed as having a powerful low gear wasn't part of the requirements.

In 2011 our strategy was to be a defensive robot that could play some tube game but mainly defense and minibot. Our low gear really helped us slow down opponents trying to get to to their scoring zone in addition to 6in plaction wheels. We used the Andymark Supershifers that came with some mounting brackets so with four 1-4 20 bolts they were a breeze to install.

In 2013 our strategy called for fast movement across the field and a slow speed to line up at the feeder station & pyramid. We debated using the Vex 3 motor single speeds, but with our CIMs allocated elsewhere and the Vexpro Ballshifters being lighter compared to the AM SuperShifters we used in previous seasons we decided to go with the light two speeds. Mounting was similar to AM however the bracket for mounting to the C-Channel placed the bolts in an odd position under the gearbox and didn't leave a lot of room for access.

We have always loved the ability to push opponents around the field in low gear or push through defenders, but by the end of this season our driver adapted to sticking in high gear and maneuvering quickly around the field to avoid pushing matches that would slow us down. At the beginning of the season the low gear was helpful but I doubt we would have seen a performance drop if we moved to single speeds. We actually saw increased performance when we dropped our speed down slightly from a 16:22 to a 12:22 reduction from the gearbox to 4in wheels. Our high gear was slower from IRI on, however our driver felt like he had much more control over the robot and could then avoid periods of having to slow down or stop to regain control.

I would say analyze your strategy and see if it fits. In 2012 the low gear was beneficial when it came time to balance as you could push opponents up the bridge or gear low enough to almost create a break effect. Your driver also needs to know when to shift to reap the benefits of the system. Many drivers get into pushing matches in high gear forgetting to shift or they stick to low gear that is easier to control and lose precious time while traveling across the field.

The kitbot is changing for 2014 so swapping for different gearboxes might not be as easy or require and updated mounting bracket, but I'm sure companies like Andymark and Vexpro will adapt.