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

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

Moderator: Moderator Team

Post Reply
Marin
Posts: 3524
Joined: Wed Jan 22, 2014 11:48 am
Location: Vienna Austria

by Marin

Disappointing gear range, especially when they have the parts and technology available in their own range.

- A versatile 2x crankset needs to be able to do combos from, say, 26/42 to 34/48 - this will give you sufficiently low gearing with a tightly spaced cassette.

- A 1x setup needs to support chainrings from 24t (loaded touring/bikepacking) to 46+ (road + light gravel) and cassettes from normal road blocks to 10-46 or 10-50 (i.e.XTR).

Plus - that group is fugly.

by Weenie


bm0p700f
in the industry
Posts: 4932
Joined: Sat May 12, 2012 7:25 pm
Location: Glermsford, Suffolk U.K
Contact:

by bm0p700f

Why moan?. I have just ordered the rd because I want 42*11-42t on my commutor bike.

Hex
Posts: 124
Joined: Sun Sep 09, 2018 10:30 am

by Hex

Been thinking of doing a mish-mash group for my "one supremo"

DA levers with DA FD and XTR RD with tanpan. All mech.

Only thing holding me down for a similarly priced di2 set up is that the XTR FD may have an issue with road crank chain clearance when in the small chairing and the largest cog and should I choose to use a mtb crankset I can't find a larger than 42t chainring for the largest ring.

I think double chainrings ftw if you get a wide cassette on the back (11-40) even if you have a standard road set front (52-39)

bm0p700f
in the industry
Posts: 4932
Joined: Sat May 12, 2012 7:25 pm
Location: Glermsford, Suffolk U.K
Contact:

by bm0p700f

Grx rd is compatible with road STI's for mechanical. Xtr FD will not work with a road chainset.

I like this new kit.

mattr
Posts: 4673
Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

One of the CX front mechs might be a better option?

bm0p700f
in the industry
Posts: 4932
Joined: Sat May 12, 2012 7:25 pm
Location: Glermsford, Suffolk U.K
Contact:

by bm0p700f

Yes it would but there is a grx FD so why not use that.

bm0p700f
in the industry
Posts: 4932
Joined: Sat May 12, 2012 7:25 pm
Location: Glermsford, Suffolk U.K
Contact:

by bm0p700f

MTB chainsets have the wrong chainline for road bike but would be i.k on some gravel bikes as they are becoming more like xc bikes with drop bars by the day.

bm0p700f
in the industry
Posts: 4932
Joined: Sat May 12, 2012 7:25 pm
Location: Glermsford, Suffolk U.K
Contact:

by bm0p700f

I think you can put an xt long cage on an Rx rear derailleur to have road rings with an 11-40t cassette.

I have been meaning to try it I have seen it on a tandem.

Marin
Posts: 3524
Joined: Wed Jan 22, 2014 11:48 am
Location: Vienna Austria

by Marin

Funny how immediately after the announcement all kinds of hacks are considered because the group doesn't offer what riders need...

Hex
Posts: 124
Joined: Sun Sep 09, 2018 10:30 am

by Hex

please delete...double post.
Last edited by Hex on Wed May 08, 2019 11:54 am, edited 1 time in total.

Hex
Posts: 124
Joined: Sun Sep 09, 2018 10:30 am

by Hex

Marin wrote:
Wed May 08, 2019 11:19 am
Funny how immediately after the announcement all kinds of hacks are considered because the group doesn't offer what riders need...
Shimano's conservative approach to max cog size is the undermining issue, I believe. People should have expressed that not only we want to use a wider range cassette with road mech, but that we want that mech to be as smooth working as that of of MTB when going from the largest cogs to the smallest cogs.

Reason I consider a mtb rd is because of the arc. Just saying that the current Ultegra R8000 (don't know how the RX800/805 or the new RDs behave) can clear the largest cog doesn't mean that shifting is ideal on the smallest cogs. We've tried it with a mate's bike after watching a couple of youtube videos seeing that it works. The chain whip when going to the smallest cogs is monumental. While my 10s XT RD city bike behaves really smoothly on the smallest cogs.

Now, whether the arc of these new RDs can really go from, say, 40t to 11t smoothly all across the cassette, remains to be seen.

I say 40 because with 36t spec max cog, surely 40t can be had....but at what cost?

Nothing against Shimano. But they could have really one-up'd SRAM here and they didn't...

mattr
Posts: 4673
Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

Hex wrote:
Wed May 08, 2019 9:33 am
I choose to use a mtb crankset I can't find a larger than 42t chainring for the largest ring.
Pretty sure i've seen up to 46 or even 48 for the current shimano 4 bolt pattern.

ooo
Posts: 814
Joined: Sat May 21, 2016 12:59 pm

by ooo

Fc-4700 have new official chainring combo 48-34
Thats 10s chainrings for 4x110
'

MichaelB
Posts: 625
Joined: Tue Apr 22, 2008 4:31 am

by MichaelB

bm0p700f wrote:
Wed May 08, 2019 10:47 am
I think you can put an xt long cage on an Rx rear derailleur to have road rings with an 11-40t cassette.

I have been meaning to try it I have seen it on a tandem.
Currently have a 10-42 & 36/46 combo working on my Slate with the RX800 RD with no issues. Sure it needs the b-screww wound in, but it wortks fine.

I like the look of the new levers to replace those munted RS505's that re on the bike now. Was looking at some RS685, but will now look for the new ones when they come out.

Just gotta find somewhere that has them !!

User avatar
themidge
Posts: 1180
Joined: Fri Jan 13, 2017 4:19 pm
Location: underneath sweet Scottish rain

by themidge

Will the new 10 speed (RX400) rear derailleur work with old Shimano 10 speed stuff like 5700, 6700, 7900, 7800, etc. or is it the same as current 10 speed Tiagra which I gather(?) is basically its own thing that doesn't work with anything else?

Kinda fancy a clutch-1x-franken-gravel-groupset for the Muddy Fox.

by Weenie


Post Reply
  • Similar Topics
    Replies
    Views
    Last post