may seem silly... missing dust cap
 

I seem to have lost the dust cap from one of my cranks. It's just the simple plastic/pry out with a small screwdriver type. I'd like to keep the grime out of my crank extractor threads.

Any thoughts on what to replace it with?

Tape

yeah, electrical tape works well here. Alternately, you can probably grab a replacement plastic dustcap at a bike shop for really cheap.
Or, you can get the allen-bolt type that fits nicely into the gap and keeps dirt out. These don't work in all cranks though, you'll have to test to see if there's space in yours. Here's an old Sugino crank that I retrofitted.
http://www.unc.edu/~cupery/pics/bike...gino_crank.jpg

Leave it off, too much weight ;).

You're crazy, the weight loss is more than negated by the increased drag coefficient. Between the crank bolt flats and the extractor thread you got a real drag king there. Careully applied teflon coated tape is the only answer.:rolleyes:

Probably, but at what speed? My answer was purely for levity. My guess is the OP, is only looking for an aesthetics solution. I am also guessing that neither tape nor leave it off will satisfy them :).

I thought you both were intentionally being [fuh-see-shuh s]. Relax guys...it's not that big a deal...really http://forums.ratedesi.com/images/sm...slapsmiley.gif

silicone caulk

Any LBS should have a drawer full of take offs and salvaged caps for next to no cost.

I had the same problem with missing dust caps on a pair of otherwise-okay rattrap pedals. Went to the local hardware store that had one of those big displays of drawersfull of odds and ends, and found a pair of black nylon plugs that fit perfectly after being trimmed to length with my Dremel. 60 cents apiece.

Are there carbon replacements available?