Quoted message said:hi,
on all my bikes as a kid there was always a large metal or plastic
round disk behind the largest cog on the rear cluster between the
largest cog and the spokes ... I assumed this was to protect the
spokes in case the chain overshifted and tried to jam between the cog
and the spokes, right?
by the time i bought my last adult bikes in the late 90's this was
normally reduced to a very thin lexan piece which was barely visible
and didn't weight much.
It still seems like a useful thing (right?) and on my old Trek the
plastic was broken so I went my a LBS to obtain another and was given
a lot of attitude by the shop worker's ... something like they are
only for kids bikes, they aren't needed, and I shouldn't have such a
sissy thing on my bike! I did notice that they didn't seem to be on
the better bikes in the shop.
They don't look cool, and they do tend to get filthy. For J. Random
Cyclist, they're probably a good idea, as not everyone is good at
adjusting derailleur stops.
Also see spoke reflectors, which I detest. In the UK they're a legal
requirement at the point of sale, but can be ripped off as soon as you
get the bike home.
