Is this fair comment...
larkim
Posts: 2,485
Just thinking about shifters, rear mechs etc etc.
The rear mech just moves between two fixed spots (A screw and B screw limits) as limited by the amount of cable the shifter plays out.
So good quality shifters should be the most important part of a rear mech change?
Also, following this thought through - why doesn't anyone (or maybe they do?) manufactuer a rear mech which has the indexed stops built into it, and leave the shifter to be a more simple switch - i.e. you click the shifter once, the rear mech moves on step along its indexed stops etc etc. rather than relying on the shifters to play out a precise amount of cable?
The rear mech just moves between two fixed spots (A screw and B screw limits) as limited by the amount of cable the shifter plays out.
So good quality shifters should be the most important part of a rear mech change?
Also, following this thought through - why doesn't anyone (or maybe they do?) manufactuer a rear mech which has the indexed stops built into it, and leave the shifter to be a more simple switch - i.e. you click the shifter once, the rear mech moves on step along its indexed stops etc etc. rather than relying on the shifters to play out a precise amount of cable?
2015 Canyon Nerve AL 6.0 (son #1's)
2011 Specialized Hardrock Sport Disc (son #4s)
2013 Decathlon Triban 3 (red) (mine)
2019 Hoy Bonaly 26" Disc (son #2s)
2018 Voodoo Bizango (mine)
2018 Voodoo Maji (wife's)
2011 Specialized Hardrock Sport Disc (son #4s)
2013 Decathlon Triban 3 (red) (mine)
2019 Hoy Bonaly 26" Disc (son #2s)
2018 Voodoo Bizango (mine)
2018 Voodoo Maji (wife's)
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Comments
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Just thinking about shifters, rear mechs why doesn't anyone (or maybe they do?) manufactuer a rear mech which has the indexed stops built into it, and leave the shifter to be a more simple switch - i.e. you click the shifter once, the rear mech moves on step along its indexed stops etc etc. rather than relying on the shifters to play out a precise amount of cable?
I think you've just described Di2
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They do make it, it's called Di2 in most cases.
What you're asking for is for a device to release an unmeasured amount of cable in either direction that the mech will automatically assign to create the movement needed to change by one [or more] gears, up or down. That's pushing normal engineering, to solve a non-existent problem. Di2 ftw.
Baah. Keefy beat me to it.
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Not sure Di2 or EPS (or the SRAM and FSA) electric kit do that - the 'brain' controls the amount of actuator movement on the mech, not the mech itself.
I guess part of the reason mechanical relies on cable pull (and electronic on actuator activation) is because of the need to adjust and trim? Also historical derailleur design where friction shifters were used. And putting a ratchet, a ratchet release mechanism and adjustment would make a derailleur unwieldily - where the levers have the room to accommodate the tech.0 -
Not sure Di2 or EPS (or the SRAM and FSA) electric kit do that - the 'brain' controls the amount of actuator movement on the mech, not the mech itself.
Di2 doesnt have a 'brain'. It has control switches and pre-set motors. The amount the mech travels is pre-programmed into the rear mech. That's why if you plug an 11 speed rear mech into a 10 speed system it will run as 11 speed. If anything the 'brain' is in the mechs.
Di2 does exactly what is described above.0 -
Not sure Di2 or EPS (or the SRAM and FSA) electric kit do that - the 'brain' controls the amount of actuator movement on the mech, not the mech itself.
Di2 doesnt have a 'brain'. It has control switches and pre-set motors. The amount the mech travels is pre-programmed into the rear mech. That's why if you plug an 11 speed rear mech into a 10 speed system it will run as 11 speed. If anything the 'brain' is in the mechs.
Di2 does exactly what is described above.
Ah, OK - my mistake - thought it was similar to EPS where the mechs are more 'dumb' and a central unit sets the travel and trim.0
