Call it lazy or maybe wanting to be quicker... I have just been running the right side since we started doing this a couple years back. Seemed to be losing a chain due to wheel impact every 3-4 races, sometimes if we drove up on someone and the wheels came off the ground in the front it would come off. Felt like it was worse as soon as i changed to 219 but i switched back to 35 and i'll be damned kid ran us over and knocked it off the next week with a new chain. Went ahead and put the other side on to see if that helps, made it through one feature so farAnd If you mean gear guard, for every 10 chains I see pop off on track 8 of them are not using gear guards.
I was just curious if there were some better than others. I see some just have a plastic piece also that is rectangular shaped.