Exciting new STI failure mode

I hope no one is too bitter about the ironic use of the
term "exciting" in the subject line. Most riders are
annoyed enough about the quirks and fragility of STI.

With that introduction, such as it is, I introduce
an decidedly unglamorous STI failure.

The cable hook assembly (horizontal cylinder)
in a left hand Tiagra STI is interfering...,
( rubbing) ....on the white plastic "thing"
(looks like polyethylene or PTFE) directly above it,
which it passes, halfway through the travel of the brake lever.

This is troublesome as it will not
let out enough cable to the spring-force-challenged
Avid Shorty 6's that it controls. If the brake
springs are wound up as far as possible, the
combination sort-of works, but expectations
are, er, higher than that. I think this problem
started two years ago, because that's when I had to
dial in max spring tension on the Shortys.

Has anyone ever seen such an problem? I'm not sure
whether is a result of a mild hit to the lever
or some other more subtle cause.

Thanks for sharing my, um, excitement!



---Roughy