I have an Outland mtb frame built used in 2005 with subject cranks from 2004 or 2005. I decided to clean it up real good after 9 years. Removing the cranks was pretty straightforward, but leaves me a bit perplexed. #1 - that end cap thingie on the left side, requiring a special tool (Park BBT-10 for example) - what the heck does that do, anyway? It's like a glorified dust cap that requires a special tool to remove. I used a screwdriver and a hammer to bang it around a couple strokes to loosen it, then undid the rest of the way with my fingers. #2 - after crank removal, I popped out the black plastic "dustcaps" with a pocket knife, removed the thin inner washers, cleaned everything up, added some grease, etc. I noticed that these black caps cover the bearings completely on the inside of the BB.
So, I guess my questions are...
1) The BB sealed bearings are behind the black plastic "dustcap" on both sides, then the crank slides through it and mates with the opposite side. Does this plastic thing then rotate along with the sealed bearings? If not, is the axle just rotating on this plastic sleeve on both ends? Yes, I'm a dolt, but for the life of me I couldn't figure out what good the bearings do when they're completely covered by the black plastic thing.
2) What useful purpose does the screw-in cap on the left crank arm serve? The allen bolts seem to bind the left and right arms together, and of course there's the little pre-load schmee-load washer on the inside of the left arm, but I can't fathom why I needed to (supposedly) get a special tool just to basically hand-torque this cap before tightening the allen bolts.
OK, I'm an old school cones and races guy, so have some sympathy.