Shimano GRX 48-31T, 46-30T - RX810, RX600, RX400

Especially for light weight issues concerning cyclocross / touring bikes & parts.

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SilentDrone
Posts: 217
Joined: Fri Sep 22, 2017 5:55 pm

by SilentDrone

fourfa wrote:If you run out of room in your FD braze-on, there are adaptors for juniors racing (which has strict limits on how tall gearing can be) to accomodate smaller chainrings:

http://wickwerks.com/products/fit-link-adapter/
Wow. I had no idea this was out there. I’ve needed one. Thanks!


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ooo
Posts: 936
Joined: Sat May 21, 2016 12:59 pm

by ooo

mechanical FD have more adjustment range comparing to di2 FD

Eccentric Shim 28.6 to 34.9 can be on round seat tube with braze-on clamp adaptor to correct chainline
chainline adjustment range: 0,5×(34,9-28,6)=3,15 mm

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by Weenie


DarkerxHalf
Posts: 35
Joined: Sat Jul 14, 2018 9:23 am

by DarkerxHalf

weiwentg wrote:
Fri Aug 16, 2019 6:27 pm
TonyM wrote:
Sat Jun 01, 2019 3:33 pm
Noctiluxx wrote:I'm interested in the RX 810 2X (48-31) crankset to replace the current Ultegra 8000 on my 2019 Giant Revolt gravel bike. I assume it should be no issue?
You will need the GRX front derailleur also (Shimano moved the chainline a bit)
Shimano's official literature should say that the GRX crankset has to go with the GRX FD. Shimano did move the GRX chainline outwards by 2.5mm.

The thing is, 2.5mm is potentially within the range of adjustment for road FDs. On this thread on the Paceline forum, one person reported using the GRX crankset with a 6870 (i.e. Di2 FD), one person said they have the GRX crank with a 6700 (!) FD, and one other guy is using the disc version of the Rotor Aldhu crankset, which has the chainline moved by 2.5mm like GRX, with a CX-70 FD (Ultegra level CX derailleur, 10s era).

I might be interested in swapping in that GRX crankset if I can adjust my FD low enough. It's a braze on mount. I'm not sure there's enough space for a 46t chainring, but there may be for a 48.
IIRC Shimano moved the chainline inward by around 2mm on R-9100 (obviously followed by R-8000 and 7000, this is also what i would assume they are bassing the new numbers of moving outward by 2.5mm) so to me it would make sense that older generation mech's would work well with the GRX crankset being spaced back out, may run into issues using current road mechs though.
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ChiZ01
Posts: 353
Joined: Wed Jan 01, 2014 6:20 pm

by ChiZ01

won't it also make sense to also dish out the free hub by 2.5mm to maintain a proper chainline?

Bcoxa
Posts: 35
Joined: Fri May 26, 2017 8:44 pm

by Bcoxa

ChiZ01 wrote:
Sat Aug 17, 2019 9:09 pm
won't it also make sense to also dish out the free hub by 2.5mm to maintain a proper chainline?
Errr how?

TurboKoo
Posts: 582
Joined: Wed Oct 29, 2008 7:55 pm

by TurboKoo

DarkerxHalf wrote:
IIRC Shimano moved the chainline inward by around 2mm on R-9100 (obviously followed by R-8000 and 7000, this is also what i would assume they are bassing the new numbers of moving outward by 2.5mm) so to me it would make sense that older generation mech's would work well with the GRX crankset being spaced back out, may run into issues using current road mechs though.
Inner chain ring was moved inward 0,4mm. In GRX the complete chain line is moved outside 2,5mm

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DarkerxHalf
Posts: 35
Joined: Sat Jul 14, 2018 9:23 am

by DarkerxHalf

TurboKoo wrote:
Sun Aug 25, 2019 5:54 am
DarkerxHalf wrote:
IIRC Shimano moved the chainline inward by around 2mm on R-9100 (obviously followed by R-8000 and 7000, this is also what i would assume they are bassing the new numbers of moving outward by 2.5mm) so to me it would make sense that older generation mech's would work well with the GRX crankset being spaced back out, may run into issues using current road mechs though.
Inner chain ring was moved inward 0,4mm. In GRX the complete chain line is moved outside 2,5mm

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Ahh, thanks for the correction, my memory doesn't always serve as well as i'd hope!
Still, 2.5mm really isnt that much and most mech's adjustment should in theory work, i guess Shimano are also covering themselves for the fact they dont produce the frames, so FD mounting points can vary, but then again they seem to enjoy saying things dont work together that do so ehh
2002 Moots Vamoots
2018 Cannondale CAAD12 Custom (RIP)
2018 Cannondale Supersix Hi Mod (SOLD)

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