Do your chainrings have bent, twisted or
missing teeth?
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Check it out...you're looking at a front chainring (the gears
attached to the pedals), and you'll notice some strange stuff.
Some teeth are shorter than others, some appear to be torn, and
others simply look like they've seen better days.
Well, believe it or not, these are all normal teeth from a
brand-new crankset! The reason for the strange profiles is
to help with shifting. For example, the low-cut teeth help
the chain to disengage from that chainring as you're shifting off
it and onto a smaller one. The funny-looking bumps on the
sides are actually designed to try and hold the chain in place for
a millisecond or two while shifting from a smaller chainring to a
larger one. How does this work? Well, when shifting
from a smaller chainring up to a larger one, the chain is trying
to fall back down...and the bumps sorta hold the chain in place
long enough for the derailleur to make an efficient shift.
On a steel chainring, these machinations can look pretty crude,
but be assured that they really do help your bike shift!
|
 Here
we're looking at a higher-quality aluminum chainring. You
can still see the shorter teeth, as well as teeth with different
(pointier) profiles than the rest. But instead of having
stamped-out "bumps" like the steel chainring, you find
riveted-in-place steel pieces at various intervals on the middle
and outside chainrings (because even if you could stamp those
bumps into place, as found on the steel chainrings, they'd be too
soft to hold up, so small steel pieces are used). |
| Please note that both of these
photos are of brand-new, never-ridden cranks! |
Last updated
09/08/07
since 05/06/05
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