Problems with Vex Pro mecanum wheels

[omsahmad]

This year we chose to use the vex pro mecanum wheels (http://www.vexrobotics.com/vexpro/wh...m-wheels.html), but are disappointed with their performance. They travel forward backwards and rotate alright, but they strife VERY slowly. I understand moving sideways is slower, but this is moving maybe 40% of forwards speed. They are mounted properly ("X" on top) and are run by one CIM motor each, with a 9.87:1 gear ratio.

Does anyone know what might be the problem? On a side note, our practice robot has "homemade" mecanum wheels from a previous year, and it works well, so I assume the code is fine.