Shimano confusion

Lets go buggy said:

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Quoted message said:

what's the difference between Shimano rapid rise /mega 9 equipment/
conventional shifting / long cage rear mechs

The spring in a Rapid Rise rear mech pulls it towards the largest sprocket
instead of the smallest, and the shifter (gear control) is designed with
that in mind.

Quoted message said:

if it's all 9 speed compatible, are all these things interchangable ?

You'd want to match the rear mech to the shifter, at least.

~PB

in message <[email hidden]>, Lets go buggy

(') said:

*** N E W B I E Q U E S TI O N A L E R T ***
*** N E W B I E Q U E S TI O N A L E R T ***

what's the difference between Shimano rapid rise /mega 9 equipment/
conventional shifting / long cage rear mechs

'Rapid rise' is a marketing abortion. It has some user interface merit
but mechanically it's just a bad idea. Yes, there's merit in having the
same action with each hand engage higher gears; no, the right way to
accomplish this is not to have the spring pull towards the largest cog
- that means more spring force, and consequently more hand force to
overcome it.

Quoted message said:

if it's all 9 speed compatible, are all these things interchangable ?

All non 'rapid rise' 9 speed Shimano stuff is interchangeable. All
'rapid rise' Shimano stuff is consignable to the dustbin of history.
Sorted.

And you're better off with SRAM anyway.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/
Das Internet is nicht fuer gefingerclicken und giffengrabben... Ist
nicht fuer gewerken bei das dumpkopfen. Das mausklicken sichtseeren
keepen das bandwit-spewin hans in das pockets muss; relaxen und
watchen das cursorblinken. -- quoted from the jargon file

Simon Brooke said:

And you're better off with SRAM anyway.

having changed chains tonight, a test ride confirms the cassette is
fubar also. Could I put an SRAM cassette on a tiagra hub with
shortcage tiagra derailleur and tiagra road-sti 9spd shifter?

best wishes
james

Lets go buggy said:

what's the difference between Shimano rapid rise /mega 9 equipment/
conventional shifting / long cage rear mechs

The spring in a Rapid Rise rear mech pulls it towards the largest sprocket
instead of the smallest. There's no difference in the gear control, so the
function of the control levers is reversed with respect to a normal system.
Rapid Rise doesn't require more force to shift.

Both systems have their partisans. Neither one is objectively better or
worse than the other. If you're used to conventional derailleurs, Rapid
Rise will probably feel a little strange at first.

Quoted message said:

if it's all 9 speed compatible, are all these things interchangable ?

Yes.

James Thomson

James Thomson said:

The spring in a Rapid Rise rear mech pulls it towards the largest
sprocket instead of the smallest. There's no difference in the gear
control, so the function of the control levers is reversed with
respect to a normal system. Rapid Rise doesn't require more force to
shift.

Surely more force is needed to shift to smaller sprockets as the
derailleur spring isn't assisting then. How do shifters that just release
cable when shifting to smaller sprockets behave with Rapid Rise mechs?

~PB

"Pete Biggs" <p@honeydewbiggs{remove_melon}.tc> wrote in message
news:[email hidden]...

Quoted message said:

James Thomson said:

The spring in a Rapid Rise rear mech pulls it towards the largest
sprocket instead of the smallest. There's no difference in the gear
control, so the function of the control levers is reversed with
respect to a normal system. Rapid Rise doesn't require more force to
shift.

Surely more force is needed to shift to smaller sprockets as the
derailleur spring isn't assisting then. How do shifters that just release
cable when shifting to smaller sprockets behave with Rapid Rise mechs?

It's all swapped. Spring pulls it towards big cog. Whereas it used to be '1'
(or whatever) on the shifter pointing to big cog, it's now '9' pointing to
big cog.

Therefore the shifter which used to release cable when shifting to small
sprockets now releases cable when shifting to big.

(Or had you already worked this out :-) )

cheers,
clive

Pete Biggs' p@honeydewbiggs{remove_melon}.tc said:

James Thomson wrote:

Quoted message said:

Quoted message said:

The spring in a Rapid Rise rear mech pulls it towards the
largest sprocket instead of the smallest. There's no difference
in the gear control, so the function of the control levers is
reversed with respect to a normal system. Rapid Rise
doesn't require more force to shift.

Quoted message said:

Surely more force is needed to shift to smaller sprockets as the
derailleur spring isn't assisting then.

Rapid Rise reverses the direction of motion of the derailleur for a given
operation of the shifter, so you need to use the direction of spring pull
as a reference to make a reasonble comparison.

The force applied to the shifter to release cable is the same in each case,
being just the force required to release the shifter ratchet. The force
required to take up cable is slightly smaller when using a Rapid Rise mech
because it's easier to move the chain down from a big sprocket to a small
one than it is to make the chain climb from a small sprocket to a big one.

Quoted message said:

How do shifters that just release cable when shifting to smaller
sprockets behave with Rapid Rise mechs?

There's no such thing as a shifter that releases cable when shifting to
smaller sprockets with a Rapid Rise mech. As you correctly stated
initially, a Rapid Rise mech moves towards the larger sprockets when cable
is released. The shifter doesn't know which direction the mech is moving -
it just pulls cable in and pays it out.

James Thomson

Clive George said:

Quoted message said:

Surely more force is needed to shift to smaller sprockets as the
derailleur spring isn't assisting then. How do shifters that just
release cable when shifting to smaller sprockets behave with Rapid
Rise mechs?

It's all swapped. Spring pulls it towards big cog. Whereas it used to
be '1' (or whatever) on the shifter pointing to big cog, it's now '9'
pointing to big cog.

Therefore the shifter which used to release cable when shifting to
small sprockets now releases cable when shifting to big.

(Or had you already worked this out :-) )

I had completely forgotten that '9' naturally becomes '1', etc, etc. :-I
:-I :-I

Thanks Clive and James.

~PB

Simon Brooke said:

'Rapid rise' is a marketing abortion. It has some user interface merit
but mechanically it's just a bad idea. Yes, there's merit in having the
same action with each hand engage higher gears; no, the right way to
accomplish this is not to have the spring pull towards the largest cog
- that means more spring force, and consequently more hand force to
overcome it.

Quoted message said:

if it's all 9 speed compatible, are all these things interchangable ?

All non 'rapid rise' 9 speed Shimano stuff is interchangeable. All
'rapid rise' Shimano stuff is consignable to the dustbin of history.
Sorted.

Seconded. RR rear mech lasted one week on my commuting bike before
becoming unreliable and being binned. For an SRAM. See below.

Quoted message said:

And you're better off with SRAM anyway.

Up to a point. That point being where the thing fails and the parts are
all non standard (SRAM 5.0) so the whole thing gets binned.

Much better spending 10 quid more and getting an XT rear mech.

...d

Quoted message said:

'Rapid rise' is a marketing abortion.

Nope. The original idea was to fix the problem of people bending the Ti
sprockets on XTR cassettes by changing too quickly/forcefully (the
spring on an RR mech lets the chain take its time to climb the
sprockets and limits the force applied; by contrast riders tend to just
shove the shifter as hard as they can even if they are almost stalled
out).

Marketing this as a way to make the controls behave the same way both
front and back instead of an engineering solution to flimsy sprockets
was an afterthought.

--
Peter Headland

Peter Headland said:

Quoted message said:

'Rapid rise' is a marketing abortion.

Nope. The original idea was to fix the problem of people bending the Ti
sprockets on XTR cassettes by changing too quickly/forcefully (the
spring on an RR mech lets the chain take its time to climb the
sprockets and limits the force applied; by contrast riders tend to just
shove the shifter as hard as they can even if they are almost stalled
out).

Marketing this as a way to make the controls behave the same way both
front and back instead of an engineering solution to flimsy sprockets
was an afterthought.

Note that Rapid-rise is now rebranded Low-Normal and is the default
option in most MTB groups
--
---
Marten Gerritsen

INFOapestaartjeM-GINEERINGpuntNL
www.m-gineering.nl

in message <[email hidden]>, David

Martin (') said:

Simon Brooke said:

All non 'rapid rise' 9 speed Shimano stuff is interchangeable. All
'rapid rise' Shimano stuff is consignable to the dustbin of history.
Sorted.

Seconded. RR rear mech lasted one week on my commuting bike before
becoming unreliable and being binned. For an SRAM. See below.

Quoted message said:

And you're better off with SRAM anyway.

Up to a point. That point being where the thing fails and the parts
are all non standard (SRAM 5.0) so the whole thing gets binned.

Much better spending 10 quid more and getting an XT rear mech.

Well frankly I binned my XTR rear mech for a SRAM 9.0, and have never
regretted it. It's very reliable, and has given no trouble at all over
a year of sturdy and adventurous off road use. comparing XT with 5.0 is
not like for like; 7.0 is XT equivalent.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/
;; First they came for the asylum seekers,
;; and I did not speak out because I was not an asylum seeker.
;; Then they came for the gypsies,
;; and I did not speak out because I was not a gypsy...
;; Pastor Martin Niemöller, translated by Michael Howard.