To deadweight or not

[JamesCH95]

A lot of things depend on what drivetrain you have... can you provide details?

A few things to think about:

Your acceleration rate with, and without, added mass.

Are you going to make your robot much more likely to stall its drive motors if you get into a pushing match? I would MUCH rather spin wheels on carpet than stall 4-6 CIMs. Handy reference chart here.

There are many different styles of defense, including just 'being in the way and making them push you sideways to get by' and what I like to call 'kinetic defense' wherein you simply repeatedly ram the other robot, throwing them off course and disrupting whatever task they're doing. Serious pushing force isn't always required for effective defense.

Making the weight easily removable so that you can be a 'heavyweight' for matches were you expect to play a lot of defense, and a 'lightweight' where you expect to play mostly offense might be the best of both worlds.

You could invest that weight into simple mechanisms to add functionality. Brakes, for instance. More durable and stickier wheels, a passive catching structure or something else to easily get the ball from the in-bounder, or a goal-tending mechanism come to mind.