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

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

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spdntrxi
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by spdntrxi

TonyM wrote:
Fri May 10, 2019 8:41 pm
spdntrxi wrote:I'm lazy... but if the GRX FD works with the XTR Di2 RD... I'm might be going back to 2x.
Why back to 2X?
(I still have to decide between 1X and 2X for my gravel bike...)
so I can have best of both worlds.. 46/32 with a 10-42 should do whatever I want.. even weighted down with gear.

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TonyM
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by TonyM

spdntrxi wrote:
TonyM wrote:
Fri May 10, 2019 8:41 pm
spdntrxi wrote:I'm lazy... but if the GRX FD works with the XTR Di2 RD... I'm might be going back to 2x.
Why back to 2X?
(I still have to decide between 1X and 2X for my gravel bike...)
so I can have best of both worlds.. 46/32 with a 10-42 should do whatever I want.. even weighted down with gear.
Which gearing do you have on your 1x?

by Weenie


spdntrxi
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Joined: Sat Jul 20, 2013 6:11 pm

by spdntrxi

40t front and 10-42(replaced to 44t).. it's fine really, and I like it more then I thought I would, but there are still a few group rides that I would probably shy away from with a 40t front. 46 might get it done

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TonyM
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by TonyM

spdntrxi wrote:40t front and 10-42(replaced to 44t).. it's fine really, and I like it more then I thought I would, but there are still a few group rides that I would probably shy away from with a 40t front. 46 might get it done
you mean for the sections on the roads?

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pdlpsher1
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Location: CO

by pdlpsher1

TonyM wrote:
Fri May 10, 2019 6:02 pm
What is the method that you use to determine the length of the chain so that you have a prope chain tension in big-big and small-small?
In my case the tandem has such long chainstays it takes an entire new chain at 116 links. I could probably add one more link but 116 link works fine so I just left it as it.

spdntrxi
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Joined: Sat Jul 20, 2013 6:11 pm

by spdntrxi

TonyM wrote:
Fri May 10, 2019 9:47 pm
spdntrxi wrote:40t front and 10-42(replaced to 44t).. it's fine really, and I like it more then I thought I would, but there are still a few group rides that I would probably shy away from with a 40t front. 46 might get it done
you mean for the sections on the roads?
yeah... I'd get dropped on downhill sections for sure... one dropped 100% and other not in the lead group.. no thanks.

MichaelB
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Joined: Tue Apr 22, 2008 4:31 am

by MichaelB

nickf wrote:
Fri May 10, 2019 1:13 pm
What kind of terrain you guys riding that you need 46/30 with a 42 out back? Honest question though. I'm a flat lander and run regular road gearing on gravel.
Many of the local dirt tracks here have sustained 12-17% gradients and are also often technical & rutted/rocky.

osw000
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Location: Girona

by osw000

MichaelB wrote:
Sat May 11, 2019 3:07 am
nickf wrote:
Fri May 10, 2019 1:13 pm
What kind of terrain you guys riding that you need 46/30 with a 42 out back? Honest question though. I'm a flat lander and run regular road gearing on gravel.
Many of the local dirt tracks here have sustained 12-17% gradients and are also often technical & rutted/rocky.
Sounds like MTB terrain
Pinarello GAN 2016 - SRAM eTap - Alu wheels. 7,2kgs.

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ultimobici
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by ultimobici

spdntrxi wrote:I'm lazy... but if the GRX FD works with the XTR Di2 RD... I'm might be going back to 2x.
Judging by the way the GRX range is presented in the compatibility chart, I doubt it will.


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spdntrxi
Posts: 2766
Joined: Sat Jul 20, 2013 6:11 pm

by spdntrxi

ultimobici wrote:
Sat May 11, 2019 9:12 am
spdntrxi wrote:I'm lazy... but if the GRX FD works with the XTR Di2 RD... I'm might be going back to 2x.
Judging by the way the GRX range is presented in the compatibility chart, I doubt it will.


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yeah I agree... bummer. The XTR Fd is not ideal for a gravel bike build with road BB.

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nickf
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by nickf

osw000 wrote:
Sat May 11, 2019 8:36 am
MichaelB wrote:
Sat May 11, 2019 3:07 am
nickf wrote:
Fri May 10, 2019 1:13 pm
What kind of terrain you guys riding that you need 46/30 with a 42 out back? Honest question though. I'm a flat lander and run regular road gearing on gravel.
Many of the local dirt tracks here have sustained 12-17% gradients and are also often technical & rutted/rocky.
Sounds like MTB terrain
Ditto. That sounds brutal and a MTB would be my choice for that terrain. Ill bring the full suspension MTB if I know an event or course is technical because you can plow through the rough stuff, and not picking through it on a road bike with big tires.

This is where the term "gravel" riding gets blurred. Single track and gravel riding are 2 different things. For me gravel is a mixture of road and a hardpack dirt, clay, gravel, crushed shell surface. Relatively smooth to a certain degree. I know on my compact 2x setup with a 11-26 I can comfortably ride 12ish% grades. On the flip I can still hit the flats in the mid 20mph range with a good cadence. So with this gearing and 45c tires your just building a rigid mountain bike that happens to have drop bars, not a gravel rig.

mattr
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by mattr

Sounds like road riding to me.

I have plenty of actual roads i use that after rain/heavy use are basically rutted out with the underlying geology exposed (rocks usually, few roots).
Can't even get to/from my house after the spring thaw without "rocky, mud filled ruts". And thats a 20% gradient (but only for 300 metres).
I do that on 700x28. Needs some finessing though!

tomh79
Posts: 86
Joined: Thu Dec 27, 2018 9:50 pm

by tomh79

I was interested in RX805 - especially after reading that many people seem to run it with up to 36 cogs (maybe more?). I'm not sure if there are any advantages to the GRX (RX815) derailleur? Specs seem to be almost the same - even weight. I think is has a bigger min. cog (30) and a higher capacity (42)? did anybody look into this?

spdntrxi
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Joined: Sat Jul 20, 2013 6:11 pm

by spdntrxi

tomh79 wrote:
Sat May 11, 2019 7:52 pm
I was interested in RX805 - especially after reading that many people seem to run it with up to 36 cogs (maybe more?). I'm not sure if there are any advantages to the GRX (RX815) derailleur? Specs seem to be almost the same - even weight. I think is has a bigger min. cog (30) and a higher capacity (42)? did anybody look into this?
40 is the pretty much the limit on the RX805.. I could use the 40 but not the 42. A goatlink might change that however, but I moved on to XTR RD and I'm happy.

by Weenie


tomh79
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Joined: Thu Dec 27, 2018 9:50 pm

by tomh79

Thanks! Thinking about 2x with a SRAM 11-36 cassette...With 30/46...

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