On Thu, 3 Jun 2004 06:37:42 +0100, "sparky.g" <[email hidden]>
Quoted message said:Does anyone out there have a Principia bike with problems shifting between
large and small rings at the Front??
This is a question for rec.bicycles.tech. Advertising is the subject
here in rec.bicycles.marketplace.
Quoted message said:rear mech and Bar end shifters. Shifting up to the large ring at the front
is almost impossible. after much grinding and stopping pedalling it shifts
up eventually. ( I don;t suppose the chain will last long)
I can't imagine how stopping pedalling would help it shift. Keep
pedalling.
Quoted message said:I have had the bike looked at by my local bike shop , who couldn't get it
working (despite having an experienced mechanic), then by the company I
purchased it from (2 hrs drive away from home). they said they found that
the gear selection cable had pulled through the sheath (and they replaced
the front Mech) and then they sent the bike back, But it is still the same,
Insist that they make it right. It's absolutely ludicrous to buy a
brand new bike and it can't shift well under average conditions. You
aren't trying to shift into extreme cross-chained positions (such as
big-big and small-small), are you?
Quoted message said:they did say bar end shifters are not as smooth as STIs. I figured it was a
This is 100% wrong. Bar-end shifters are optimum for front shifting;
STI is great for the rear. The rear is a precision application using
capable equipment and under little stress; the front is a
caveman-like shove of the tensioned side of the chain, which also
wants easy micro-adjustments -- perfect for bar-end (and other
friction-type) shifters.
Anyway, if they really think it should be so difficult to shift with
bar end shifters, they should not sell them.
Quoted message said:problem with the frame and was about the get them to swap it for a Rexe Pro
frame instead (they have bolt on frame lugs where as the T2 is braised on).
How could frame joint style affect shifting?
Quoted message said:But!!
At a race last night I was speaking to someone who was frustrated and having
the same problem with her Principia, Rexe Pro, with Full Dura-ace all round
including the STi.s
Sounds like you and her both have incompetent mechanics.
Quoted message said:So anyone else have this problem ?? Is it an issue with Principia frame
geometry.
I just looked on the Principia site, and I don't see anything
radical about the geometry.
Quoted message said:Note my £600 Giant with Tiagra components shifts sweet every time in any
situation (even with about 4000 miles on it), so surely I should expect
equal if not better performance from a new £3000 bike?
You absolutely should, and you should expect quicker, easier front
shifting with bar end shifters.
It's possible that, when they fixed it, it worked for them on a
test-ride. However, you should probably go there, insist that they
fix it, and test-ride it around there before going home with it.
It sure sounds mostly like the H screw on the front derailer needs
to be adjusted and/or the cable has too much slack.
Assuming it shifts just as badly on a workstand as on the road, try
pulling on the cable itself where it's exposed at the downtube while
pedalling with your other hand. Just pull the cable away from the
downtube. If that works fine, then it's somewhere between your hand
and the shifter.
If that doesn't help, try adjusting the H screw. Then, pull the
cable by hand again; if it works, then try the shifter. Etc.
Here's some shot-in-the-dark ideas as to what else could be wrong:
- Incompatible parts (off-brand chain or crank?)
- Bad chainring
- Bad derailer, shifter, or cable
- Cable getting stuck somewhere
--
Rick Onanian