>>1158612water and shit can get in through holes and inside in your frame. especially through that hole for the plastic cable routing guide on the bottom of the BB, that plastic thing is there to block it and stop shit getting into the BB bearings as they are big and unusually sensitive in my experience.
The plastic tube doesnt do much but doesnt do nothing either. Its not needed for spacing, the washers do that job, but be warned i left the tube out when i put some ceramic bearings on my saint cranks - and got caught in salty flood waters last years and it totally fucked my shit up. The races rusted and my BB seized and was ruined.
Not worth it in my opinion
