Tiagra 4700 (RS405) new "vivid index shifting" 10sp vs 11sp

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ooo
Posts: 1590
Joined: Sat May 21, 2016 12:59 pm

by ooo

Any one understand how exactly 10sp Tiagra 4700 "uses same cable pull and/or ratio as shimano road 11sp" ?
I have found 2 contradicting theories (which one is correct?) :

1st theory
- RD-4700 have exact same geometry as 11sp RD (ST-4700 uses new special pull to respect that)
- 11sp STI + RD-4700 = shifting 11sp cassette perfectly
- 10sp ST-4700 + 11sp road RD = shifting 10sp cassette perfectly

2nd theory
- ST-4700 have exact same pull like 11sp STI minus 1 click (RD-4700 uses new special ratio to respect that)
- 11sp STI + RD-4700 = shifting 10sp cassette perfectly + 1 idle click
- 10sp ST-4700 + 11sp road RD = shifting 10 cogs of 11sp cassette + 1 cog unreachable


unrelated 4700 tests on youtube (4700 incompatibility with other 10sp parts - not about my question) :
http://www.youtube.com/watch?v=dIkKSdNBoro - 10sp ultegra RD fail test with 10sp tiagra 4700 shifter (followed by successful test 4700 RD) :
http://www.youtube.com/watch?v=Q4IzJdHTUjE - RD-4700 + ST-5700 bad shifting (text comments here)


links to PDFs:
RD-4700 ST-4700 ST-RS405
RD-5800 ST-5800 ST-RS505
RD-U5000
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raisinberry777
Posts: 313
Joined: Wed Jul 30, 2014 1:09 am

by raisinberry777

ooo wrote:Any one understand how exactly 10sp Tiagra 4700 "uses same cable pull and/or ratio as shimano road 11sp" ?
I have found 2 contradicting theories (which one is correct?) :

1st theory
- RD-4700 have exact same geometry as 11sp RD (ST-4700 uses new special pull to respect that)
- 11sp STI + RD-4700 = shifting 11sp cassette perfectly
- 10sp ST-4700 + 11sp road RD = shifting 10sp cassette perfectly


This. Derailleurs do not work on 'speeds' as such, they only care about the amount of cable pull. For example, 8/9/10 speed Shimano derailleurs (the old style, not including Sora R3000 and Tiagra 4700) are all cross compatible as the cable pull from the shifters was the same until the change with Dura Ace 9000.

ooo
Posts: 1590
Joined: Sat May 21, 2016 12:59 pm

by ooo

New sora have "vivid index shifting" text in description, but I think is old style compatible.
In compatibility tables RD-R3000 and RD-3500 are in the same boxes (unlike RD-4700 and RD-4600)

Image
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