Paul Myron Hobson said:...with down tube or bar-end shifters
My options:
1) Get a bash guard to keep the chainring from derailing towards the
outside. (Do I need a seat tube mounted chain catcher?)
2) Use a part-bin front derailer/shifter with extreme limits set (but
still be able to trim it for highest/lowest gears).
3) Is there a #3?
Which do y'all like better? Also, any guess as to the chainline I'm
looking for?
I'll go ahead and say 'Muchos gracias' for the help!
\\paul
for chainline, it's basically determined by what the over-locknut
spacing is, although technically each hub/cassette combo is gonna put
the middle of the cassette in a very very slightly different place. if
you're running a 1-by-whatever setup that makes it absolutely
impossible for the chain to fall off in front (a good idea), then if
it makes sense you can bias the front chainline a bit if you heavily
favor certain gears, although usually this won't make make sense or
make any difference.
there are 2 setups missing from your list. first is this kind of
thing: http://www.peterwhitecycles.com/Cyclo-Cross.htm . they are
somewhat rarely seen but are probably the most functional, elegant
option. i havent done this, but you could probably use a pair of these
(http://www.spotbikes.com/parts/) or one of the similar guards and
some really long chainring bolts (sugino and problem solvers both make
em) to set up your own. you could probably also use some big, worn out
chainrings with the teeth ground off instead of buying guards.
second is chainguides for dh/freeride/4x/etc, which of course i'm only
mentioning for posterity, although they do accomplish the function
we're talking about and would like pretty awesome on a bike with
downtubes $$$