Q: Somebody please explain my new gear shift

[M-gineering]

Rob Morley wrote:
> In article <[email protected]>, M-gineering
> [email protected] says...
>> Tony Raven wrote:
>>
>>> I have seen rear mechs that had a pull cable for each direction of
>>> movement rather than relying on a spring for one direction. Didn't know
>>> Shimano did them
>> Positron, early seventies
>>
> The only Positron I'm familiar with had a push-pull piano-wire cable,
> and no spring in the rear mech.

probably a later version, the 74 catalogue list a 'NEW' axle mounted
positron with dual cables.

--
/Marten

info(apestaartje)m-gineering(punt)nl

 

[Martin Dann]

Ace wrote:
>
> To clarify for the OP, the extra cable would drive a central gear
> position display. Why you'd need one I don't know - many modern MTB
> shifters don't even bother to put numbers on the displays, and I
> personally never look at them anyway.

I often glance at mine. When I am about to stop at traffic
lights, I need to make sure I am in the right gear to pull
away again. I find if I don't look, then sometimes I try
to pull away in the wrong gear.

Also when I am cycling without a computer, I estimate my
speed from the gear and cadence.

Martin.

 

[Martin Dann]

Tony Raven wrote:
> Ace wrote:
>>
>> To clarify for the OP, the extra cable would drive a central gear
>> position display. Why you'd need one I don't know - many modern MTB
>> shifters don't even bother to put numbers on the displays, and I
>> personally never look at them anyway.
>
> You need the numbers to confirm that there really isn't another gear
> left to desperately change down to on that hill ;-)

If I ever get hills that steep, I find it quicker to get
of and walk. Even in Bristol I don't have to do that.

 

[Paul Boyd]

Ace said the following on 31/07/2007 17:51:

> To clarify for the OP, the extra cable would drive a central gear
> position display. Why you'd need one I don't know - many modern MTB
> shifters don't even bother to put numbers on the displays, and I
> personally never look at them anyway.

My MTB shifters don't have numbers - Shimano can't know whether you are
using the shifters with low-normal or top-normal mechs. I did actually
think about taking the indicators off the shifters as being a bit
unnecessary, but I find that I do glance at them now and again. If I'm
dragging up a 1-in-silly hill off-road, I like to know in advance if I
have any gears in reserve at the back before having to drop a ring at
the front

--
Paul Boyd
http://www.paul-boyd.co.uk/

 

[Ace]

On Wed, 01 Aug 2007 17:00:09 +0100, Paul Boyd
<usenet.dont.work@plusnet> wrote:

>Ace said the following on 31/07/2007 17:51:
>
>> To clarify for the OP, the extra cable would drive a central gear
>> position display. Why you'd need one I don't know - many modern MTB
>> shifters don't even bother to put numbers on the displays, and I
>> personally never look at them anyway.
>
>My MTB shifters don't have numbers - Shimano can't know whether you are
>using the shifters with low-normal or top-normal mechs.

I'd never heard of these until this thread. What's the point ot them?
And are they a recent thing, or what?

> I did actually
>think about taking the indicators off the shifters as being a bit
>unnecessary, but I find that I do glance at them now and again. If I'm
>dragging up a 1-in-silly hill off-road, I like to know in advance if I
>have any gears in reserve at the back before having to drop a ring at
>the front

I'm sure I must look at mine, both the numbered and unnumbered ones,
from time to time, but my road bike (with 105 sivelling brake lever
change) clearly don't have them, and perhaps over the pre-indexed
years I'd developed a habit of actually looking down at the gears,
which has stuck with me to this day.

--
Ace in Alsace - brucedotrogers a.t rochedotcom

 

[Rob Morley]

In article <[email protected]>, M-gineering
[email protected] says...
> Rob Morley wrote:
> > In article <[email protected]>, M-gineering
> > [email protected] says...
> >> Tony Raven wrote:
> >>
> >>> I have seen rear mechs that had a pull cable for each direction of
> >>> movement rather than relying on a spring for one direction. Didn't know
> >>> Shimano did them
> >> Positron, early seventies
> >>
> > The only Positron I'm familiar with had a push-pull piano-wire cable,
> > and no spring in the rear mech.
>
> probably a later version, the 74 catalogue list a 'NEW' axle mounted
> positron with dual cables.
>
I wonder why that didn't work out - it seems like a reasonable idea.

 

[Paul Boyd]

Ace said the following on 01/08/2007 21:12:

> I'd never heard of these until this thread. What's the point ot them?
> And are they a recent thing, or what?

They are fairly recent. They were developed, AFAIK, to work with the
dismal failure that is dual-control levers [1], and for some reason
these worked the cable pull backwards. In my case, and lots of other
people's, I simply prefer the reverse action, so my thumb moves it into
a higher gear and my index finger moves it into a lower gear, using
standard trigger shifters. No real, logical explanation - it just feels
more natural to me! It also means I can shift several gears at once in
the low to high direction which is more useful to me than shifting lots
of low gears at once.

> I'm sure I must look at mine, both the numbered and unnumbered ones,
> from time to time, but my road bike (with 105 sivelling brake lever
> change) clearly don't have them, and perhaps over the pre-indexed
> years I'd developed a habit of actually looking down at the gears,
> which has stuck with me to this day.

I must admit that I do also tend to glance down most of the time. Put
it this way - I wouldn't miss the indicators if they weren't there, and
the 105 bar-end shifters on my other bike don't have any indicators!

[1] - yes, I have tried them, then found I could barely give them away
on eBay :-( And yes, I know someone will now come along and say
dual-control on MTBs is the best thing since sliced bread

--
Paul Boyd
http://www.paul-boyd.co.uk/