I understand some folks want to protect their oil filter. That's easy to do with a quick steel cover that runs $30. I don't care if my filter gets a dent or two; it's only on the bike temporarily anyway. I would very much care if it got a puncture, though. However, with even the Triumph aluminum sump guard, the oil filter is protected from debris being flung up from the front tire. Any foreign object would have to come at the filter from an unexpected angle to contact it. The Triumph sump guard also allows access to the oil filter for maintenance purposes, without having to remove the sump guard.