Sirrus and Tiagra

in message <[email hidden]>, Nick

('nickandoscar@REMOVE THIS TO REPLYtiscali.co.uk') said:

Very nice too, except for the front changer (Tiagra, I think, and
rapidfire shifters, 24 speed). Seemed to be an unusually ltd range of
gears available before the changer cage starting scraping on the
chain: something like

Biggest chainwheel:- only top 3-4 sprockets usable
Middle :- middle 5-6 only
Small: - bottom 5 only
Also, changer took a little coaxing to climb from lowest chainwheel
(30) to middle (42).
Chainwheel looked fine - no warps or anything I could see.

The very patient shop mechanic (at FW E**ns) adjusted the changer a
few times for me, but without making a significant difference. He
reckoned this was normal: to do with a compromise between the changer
and the gear ratios. We discussed whether a more MTB inclined changer
would operate better, but he said he'd never tried this.

This is the problem with Shimano shifters. Campag (road) and SRAM (MTB)
front mech shifters allow finer grained adjustments and consequently
the mech can be trimmed. I no longer have Shimano shifters on any of my
bikes for precisely this reason.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; Madness takes its toll. Please have exact change.

so ... should I expect better performance than I got? And could I fit a
different changer, using the rapidfire shifters?

NJ
"Simon Brooke" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

in message <[email hidden]>, Nick

('nickandoscar@REMOVE THIS TO REPLYtiscali.co.uk') said:

Very nice too, except for the front changer (Tiagra, I think, and
rapidfire shifters, 24 speed). Seemed to be an unusually ltd range of
gears available before the changer cage starting scraping on the
chain: something like

Biggest chainwheel:- only top 3-4 sprockets usable
Middle :- middle 5-6 only
Small: - bottom 5 only
Also, changer took a little coaxing to climb from lowest chainwheel
(30) to middle (42).
Chainwheel looked fine - no warps or anything I could see.

The very patient shop mechanic (at FW E**ns) adjusted the changer a
few times for me, but without making a significant difference. He
reckoned this was normal: to do with a compromise between the changer
and the gear ratios. We discussed whether a more MTB inclined changer
would operate better, but he said he'd never tried this.

This is the problem with Shimano shifters. Campag (road) and SRAM (MTB)
front mech shifters allow finer grained adjustments and consequently
the mech can be trimmed. I no longer have Shimano shifters on any of my
bikes for precisely this reason.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; Madness takes its toll. Please have exact change.

Nick said:

so ... should I expect better performance than I got? And could I

fit a

Quoted message said:

different changer, using the rapidfire shifters?

You could fit any Shimano mech. from any range from any year but I
think the problem is one of adjustment not components. In replacing the
mech. you will adjust it so it will be difficult to tell if the new
component or the new adjustment solved the problem. So you can't use
big front and 3 big rear without the chain rubbing on the front mech. ?
You could probably get it better than this with careful adjustment but
if youuse these combinations your chain line will be poor and your
chain will wear out more quickly than if you hadn't. You could use a
different type of shifter such as a friction type and [censored] around
trimming the mech. but you'd still have a [censored] chainline. You will find
that you have almost indentical gears with a better chainline anyway so
it really isn't worth the bother IMHO.

"Nick" <nickandoscar@REMOVE THIS TO REPLYtiscali.co.uk> wrote in message news:<[email hidden]>...

Quoted message said:

so ... should I expect better performance than I got? And could I fit a
different changer, using the rapidfire shifters?

I'd be inclined to do things the other way round - I'm assuming from
the mention of Rapidfire shifters that it's a model with flat not
dropped bars? If this is the case, stick with your original front
changer, but go for a set of compatible SRAM shifters (left- *and*
right-hand), as this will - as Simon has already remarked - allow for
"fine-tuning" of the front mech and get rid of unpleasant scraping
sounds, etc.

David E. Belcher

Thanks for responses.

Nick

"David E. Belcher" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

"Nick" <nickandoscar@REMOVE THIS TO REPLYtiscali.co.uk> wrote in message

news:<[email hidden]>...

Quoted message said:

Quoted message said:

so ... should I expect better performance than I got? And could I fit a
different changer, using the rapidfire shifters?

I'd be inclined to do things the other way round - I'm assuming from
the mention of Rapidfire shifters that it's a model with flat not
dropped bars? If this is the case, stick with your original front
changer, but go for a set of compatible SRAM shifters (left- *and*
right-hand), as this will - as Simon has already remarked - allow for
"fine-tuning" of the front mech and get rid of unpleasant scraping
sounds, etc.

David E. Belcher

Simon Brooke said:

in message <[email hidden]>, Nick

('nickandoscar@REMOVE THIS TO REPLYtiscali.co.uk') said:

Very nice too, except for the front changer (Tiagra, I think, and
rapidfire shifters, 24 speed). Seemed to be an unusually ltd range of
gears available before the changer cage starting scraping on the
chain: something like

Biggest chainwheel:- only top 3-4 sprockets usable
Middle :- middle 5-6 only
Small: - bottom 5 only
Also, changer took a little coaxing to climb from lowest chainwheel
(30) to middle (42).

That sounds OK to me and is good practice anyway, to minimise wear and
get good chain efficiency.

FWIW anything with a triple front chainset usually needs some trimming,
and modern Shimano levers make this difficult.

in message <[email hidden]>, Nick

('nickandoscar@REMOVE THIS TO REPLYtiscali.co.uk') said:

"David E. Belcher" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

"Nick" <nickandoscar@REMOVE THIS TO REPLYtiscali.co.uk> wrote in
message

news:<[email hidden]>...

Quoted message said:

Quoted message said:

so ... should I expect better performance than I got? And could I
fit a different changer, using the rapidfire shifters?

I'd be inclined to do things the other way round - I'm assuming from
the mention of Rapidfire shifters that it's a model with flat not
dropped bars? If this is the case, stick with your original front
changer, but go for a set of compatible SRAM shifters (left- *and*
right-hand), as this will - as Simon has already remarked - allow for
"fine-tuning" of the front mech and get rid of unpleasant scraping
sounds, etc.

Thanks for responses.

Word of warning here: SRAM shifters come in two cable pull versions,
those for their own deraileurs and those for Shimano deraileurs. The
two are *not* compatible, and if you have Shimano deraileurs you need
to make sure you get the right ones. But frankly I would strongly
recommend doing this. I very much like the SRAM 'gripshift' (i.e.
twist-type) shifters and now have them on two bikes, one with Shimano
and one with SRAM deraileurs.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

---===***<<< This space to let! >>>***===---
Yes! You, too, can SPAM in the Famous Brooke Rotating .sig!
---===***<<< Only $300 per line >>>***===---

[email hidden] (David E. Belcher) wrote in message news:<[email hidden]>...

Quoted message said:

"Nick" <nickandoscar@REMOVE THIS TO REPLYtiscali.co.uk> wrote in message news:<[email hidden]>...

Quoted message said:

so ... should I expect better performance than I got? And could I fit a
different changer, using the rapidfire shifters?

I'd be inclined to do things the other way round - I'm assuming from
the mention of Rapidfire shifters that it's a model with flat not
dropped bars? If this is the case, stick with your original front
changer, but go for a set of compatible SRAM shifters (left- *and*
right-hand), as this will - as Simon has already remarked - allow for
"fine-tuning" of the front mech and get rid of unpleasant scraping
sounds, etc.

Just as a follow up/clarification, I've been to www.sram.com, and the
2004 models in question are MRX, Centera, Rocket and Attack - these
are designed to be Shimano compatible, the latter two being available
in both twist-shift and trigger-shift types. Other SRAM right-hand
shifters are designed to work with a slightly different type of
SRAM-designed rear mech and may cause problems if used with Shimano.

David E. Belcher

many thanks.

Nick

"David E. Belcher" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

[email hidden] (David E. Belcher) wrote in message

news:<[email hidden]>...

Quoted message said:

Quoted message said:

"Nick" <nickandoscar@REMOVE THIS TO REPLYtiscali.co.uk> wrote in message

news:<[email hidden]>...

Quoted message said:

Quoted message said:

Quoted message said:

so ... should I expect better performance than I got? And could I fit

a

Quoted message said:

Quoted message said:

Quoted message said:

different changer, using the rapidfire shifters?

I'd be inclined to do things the other way round - I'm assuming from
the mention of Rapidfire shifters that it's a model with flat not
dropped bars? If this is the case, stick with your original front
changer, but go for a set of compatible SRAM shifters (left- *and*
right-hand), as this will - as Simon has already remarked - allow for
"fine-tuning" of the front mech and get rid of unpleasant scraping
sounds, etc.

Just as a follow up/clarification, I've been to www.sram.com, and the
2004 models in question are MRX, Centera, Rocket and Attack - these
are designed to be Shimano compatible, the latter two being available
in both twist-shift and trigger-shift types. Other SRAM right-hand
shifters are designed to work with a slightly different type of
SRAM-designed rear mech and may cause problems if used with Shimano.

David E. Belcher