New Shimano Gravel GRX Groupset

[AUbicycles]

Today Shimano launched a new Gravel specific groupset called GRX with 3 series, 400, 600 and 800.

Road style brakes / shifters with MTB style rear derailleur. It runs in 10-speed and 11-speed mechanical and 11-speed Di2 (electronic). In addition there are brake calipers (400 and 800 series) and one wheelset. 1x and 2x are possible (if I read correctly).

https://gravel.shimano.com/en/components


One thing I noticed was some cross-compatibility - something which was not easy (but not impossible) when connecting Shimano MTB and road gear. The exact limits and options need a bit more investigation.

Also noticed 4 standard crank lengths 165, 170, 172.5 and 175mm.

The shifters / brakes have a concave type profile, unlike the convex profile in road shifters. I noticed a 'sub-brake' level - like MTB type brakes and it appears that it can be used in combination with dropbar brakes... so essential two brakes ... It reminds me of the suicide levers that were popular years ago but as a hydraulic type system (and a modern braking system) I don't anticipate the same issues... however can mean a rethink or even optimisation of the handlebars to deliver enough space.

[10speedsemiracer]

So it would seem the rx400 is Tiagra gravel, rx600 is 105 equivalent and rx800 appears to be Ultegra equivalent. I think the Ultegra Rx derailleur release recently should have been a clue.

[10speedsemiracer]

Very interesting component group, seems the chainrings and FD have been pushed outward for chainline clearance for larger rubber (+2,5mm), some hefty cassette options in terms of big cog at the rear and overall chain wrap plus a wheelset (WH-RX570-TL) amongst other things.

[Calvin27]

One thing I noticed was some cross-compatibility - something which was not easy (but not impossible) when connecting Shimano MTB and road gear. The exact limits and options need a bit more investigation.

The golden era was when SRAM had 1:1 actuation across their entire 10 speed range. This basically allowed myself and a few others to do all sorts of crazy 1x11-40 monstercross setups that would be impossible without a lot more stuffing around.

These days though I don't really see a need because even road gear has gotten some decent cassette range.

[gsxrboy]

I always wonder why they don't start the cassettes at 13 or 14 and fill in a few more holes at the larger end. For the target usage, being able to drop into a 11 and do 50kph at xx cadence seems a bit daft on most gravel/adventuring. I could understand it more if they had a stock 32T fronts instead of 40 and 11/42 etc

So looking at my riding, cadence and the gears I generally use in commuting and when I toured on a 44/36 11/28, a 1x 32 (likely oval) and 10/33 12s Force would be even better and more useful than anything in this new groupset.

[MichaelB]

...

These days though I don't really see a need because even road gear has gotten some decent cassette range.

I'm with you here.

Currently running 10-42 & 36/46 with RX800 RD and std road crank with compact BCD. Sure it requires a fair bit of B screw, but still works and gives me a good low end, and sensible top end.

Winner !!!

Only curious whether the GRX levers have the same cable actuation as the road shifters.

[Calvin27]

Only curious whether the GRX levers have the same cable actuation as the road shifters.

I'd give the brake lever pivot points though. One of my problems is even with hydro, the hoods need a lot more brake force when on the tops.

[singlespeedscott]

I’m very excited to see this stuff. Particularly like the “non” hollow tech 46/30 crankset.

[10speedsemiracer]

GCN review of GRX

[ironhanglider]

I always wonder why they don't start the cassettes at 13 or 14 and fill in a few more holes at the larger end. For the target usage, being able to drop into a 11 and do 50kph at xx cadence seems a bit daft on most gravel/adventuring.

I am right with you here. I can't push big gears anymore, besides there is less friction in bigger cogs.

Cheers,

Cameron

[MichaelB]

Only curious whether the GRX levers have the same cable actuation as the road shifters.

I'd give the brake lever pivot points though. One of my problems is even with hydro, the hoods need a lot more brake force when on the tops.

I was referring to the FD & RD cable pull, not the brake actuation

[2wheels_mond]

I was referring to the FD & RD cable pull, not the brake actuation

Yes to both, but the front needs to be used with the 2x GRX crankset.

See the compatibility chart here: https://productinfo.shimano.com/#/

[MichaelB]

I was referring to the FD & RD cable pull, not the brake actuation

Yes to both, but the front needs to be used with the 2x GRX crankset.

See the compatibility chart here: https://productinfo.shimano.com/#/

Thanks for the link.

The way I read the Compatibility chart, the new GRX FD needs to be paired with the GRX crankset, due to the +2.5mm movement outboard for wider tyre clearance, but I'd only be using the new GRX levers on an existing setup, so the crank and FD are road units.

And it seems to confirm GRX levers are fully compatible with Road derailleurs.

Now just gotta find somewhere to buy them from !!! Need either the RX810 or RX600 Shift lever set

[Ross]

Now just gotta find somewhere to buy them from !!! Need either the RX810 or RX600 Shift lever set

Not coming to Oz until July or August. Maybe OS a few weeks earlier, according to Cycling Tips
https://cyclingtips.com/2019/05/shimano ... o-weights/

[Duck!]

Only curious whether the GRX levers have the same cable actuation as the road shifters.

I'd give the brake lever pivot points though. One of my problems is even with hydro, the hoods need a lot more brake force when on the tops.

I was referring to the FD & RD cable pull, not the brake actuation

Shifter internals are the same as road models - RX400 <-> 4700 Tiagra, RX600 <-> R7000 105, RX810 <-> R8000 Ultegra.

[Mububban]

Here 'tis




Basic summary:

RX815 = equivalent to Ultegra Di2
RX800 = Ultegra
RX600 = 105

11spd available in 1x or 2x.

RX400 = Tiagra (2x10 only)

Gearing options:
1x = 40 or 42t chainring
11-40 or 11-42 cassettes
Any 11 speed cassette is theoretically compatible

2x = 48-31 or 46-30 chainrings
Clutched rear derailleur
2x rear derailleurs can handle up to 34t cassettes

New levers prioritise braking via the hoods for drops and descents, which gravel riders tend to prefer vs using the drops.

[lone rider]

Cant believe how good this. Almost silent. Last mech groupset I have is 5800, I have 800 in this and its is miles better, the shifting action is so light and crisp and no chain noise at all.

[warthog1]

Yeah I have it on my Revolt. A mix match. 400 disc calipers, 600 levers and 800 derailleurs. Has a Praxis Alba chainset in 48/32 and currently using a Sram 36-11 cassette. Can't remember what brand of chain I am running currently.
Works well. Very happy with it.

[Retrobyte]

Same here - my Norco Search gravel commuter has the same GRX mix as the Revolt, although the previous owner converted it to a 1x11. Has a Wolftooth 44 chainring and an 11-42 Sunrace cassette. Runs as quietly as my Ultegra roadie

[nezumi]

Is it possible to find this in the wild yet, or is supply still so low that it's only really available on pre-built bikes?

[owly]

Is it possible to find this in the wild yet, or is supply still so low that it's only really available on pre-built bikes?

Alexscycle Japan has some 8...level components, apart from cranksets.