D
Doug McLaren
Guest
I recently picked up a Trek 2000 Alpha SL bike used, and I've been
fixing it up. I don't know the year, but from what I was told I'm
guessing late 1990s.
It's got Shimano RSX components.
So, the first thing broken was the left/front shifter (it's a three
speed brifter.) Would shift up but not down. Cleaned it up with
WD-40 and it did start working, though it sounds like there's still
grit in there.
However, it could barely shift the gear -- I have to really crank down
on it. The right shifter/rear derailleur is much easier. The
derailleur itself seems fine, the cables are fine (and the routing is
correct), so I found a replacement brifter, and put it in. Same
problem.
Upon closer investigation, to move the front derailleur from the
loosest position by pulling the cable manually away from the frame
between the two braze-ons on the bottom tube requires a lot more
effort than my other bike.
Removing the derailleur, it seems fine, but it requires a _lot_ of
effort to move it. It's not stuck -- it slides freely, and it
requires just as much effort to `compress' it as it does to keep it
from uncompressing. It's like they put a big honking spring in there,
far larger than I'd think was needed. I've certainly never heard of a
spring failing in such a way to *increase* the tension, so I'm quite
confused by this -- it's like it was designed this way, but it just
doesn't seem right.
To be fair, I don't have a lot of experience fixing bikes -- I sort of
know what I'm doing, and have books to refer to, but don't have the
experience to tell me what sort of tension to expect here -- but it
seems way too high, like 2-3x as high as it ought to be.
Looks like it's a FD-A417 Chainstay angle 63-66 degrees. Looking
carefully at the spring while it's moved, it looks like the entire
spring is working and is clean and not rusted and such.
Thoughts?
--
Doug McLaren, [email protected]
`The chief obstacle to the progress of the human race is the human race.'
- Don Marquis.
fixing it up. I don't know the year, but from what I was told I'm
guessing late 1990s.
It's got Shimano RSX components.
So, the first thing broken was the left/front shifter (it's a three
speed brifter.) Would shift up but not down. Cleaned it up with
WD-40 and it did start working, though it sounds like there's still
grit in there.
However, it could barely shift the gear -- I have to really crank down
on it. The right shifter/rear derailleur is much easier. The
derailleur itself seems fine, the cables are fine (and the routing is
correct), so I found a replacement brifter, and put it in. Same
problem.
Upon closer investigation, to move the front derailleur from the
loosest position by pulling the cable manually away from the frame
between the two braze-ons on the bottom tube requires a lot more
effort than my other bike.
Removing the derailleur, it seems fine, but it requires a _lot_ of
effort to move it. It's not stuck -- it slides freely, and it
requires just as much effort to `compress' it as it does to keep it
from uncompressing. It's like they put a big honking spring in there,
far larger than I'd think was needed. I've certainly never heard of a
spring failing in such a way to *increase* the tension, so I'm quite
confused by this -- it's like it was designed this way, but it just
doesn't seem right.
To be fair, I don't have a lot of experience fixing bikes -- I sort of
know what I'm doing, and have books to refer to, but don't have the
experience to tell me what sort of tension to expect here -- but it
seems way too high, like 2-3x as high as it ought to be.
Looks like it's a FD-A417 Chainstay angle 63-66 degrees. Looking
carefully at the spring while it's moved, it looks like the entire
spring is working and is clean and not rusted and such.
Thoughts?
--
Doug McLaren, [email protected]
`The chief obstacle to the progress of the human race is the human race.'
- Don Marquis.