Shimano GRX “groupset” launched.

[ElCani]

https://road.cc/content/tech-news/26009 ... -need-know

[honesty]

Interesting. Seems they’ve got the interruptor lever sorted for hydraulic braking as well.

[iandriver]

Love the comment below the article

Seems like an awful lot of effort to avoid making "road" levers with "mountain bike" cable pull or vice-versa.

[ratherbeintobago]

Interesting. Seems they’ve got the interruptor lever sorted for hydraulic braking as well.

I wonder how they’ve got that to work? I suppose in theory it could be done with a second master cylinder…

[thelawnet]

Ok but did you know they also released a new Tiagra 'groupset'?

https://www.bikehub.co.za/features/_/ge ... stem-r7819

It's somewhat smoke, mirrors, and marketing, but now the Tiagra hydraulic STIs match the 105, Ultegra, Dura-Ace.

Which makes the 105 bikes with hybrid disc brakes look a bit stupid.

Anyway:

Brifters:

RX400 - they are Tiagra level
RX600 - they are 105
RX810 - they aren't quite Ultegra, as the levers are aluminium (cold!) rather than composite

The rear derailleurs:

RX810 it's similar (though slightly different construction) to the existing Ultegra RX. Nothing terribly interesting e.g. if you want more range for touring or whatever.
RX812 it's 1x specific for 11-40 or 11-42 cassette. Capacity is slightly less, but probably work better if you like dinner plates on your rear wheel.
RX400 it's interesting in that it's a 10 speed road clutch derailleur. Except that well if you wanted one you could have just used the 11-speed Ultegra RX. So nothing new here either.

Front derailleurs are 46mm rather than 43.5mm (road) or 50mm (mtb) chainline, top swing so they can get nice and dirty.

Brakes:

they are the same as Tiagra (RX400) and 105/Ultegra (which are identical) (RX810)

Chainsets:

There is RX810-11/RX810-1, which they are claiming is Ultegra level, but in any case Ultegra and 105 are identical unless you are incredibly gullible, and it's different from both (aluminium rather than composite chainrings), and RX600-11 or RX600-1, which they are claiming is 105, but is actually more like non-series 11-speed (RS510), which you probably got on your 105 bike anyway. There is a choice of 48-31 (ooh, a 17t gap, such progress), or 42 or 40t single chainring, which is what counts for progress on planet Stupid (lowest ratio is 40/42, cf. a standard road triple with 30/34), So a bigger chainring gap for worse shifting performance, and a 48/11 to 31/34 on the double (cf. 50/11 to 30/34 on a triple).

The RX600-11 and RX600-10 is for those with less money, which means they aren't as strong (or something) so they get 46/30 meaning 46/11 to 30/34.

You can't use the 46/30 chainsets with your existing 11-speed or 10-speed road bikes because of the different chainline.

The RX600-1 doesn't get the 42t option, because poorer people can't push big chainrings so here it's just 40 / 11-42. But still 11-speed. Sorry no 1x for the 10-speed plebs.

The wheels are all 24-spoke, because gravel means 'no potholes'. I think. Oh and aluminium axles.


There's nothing like STIs compatible with MTB derailleurs, it's just same old road stuff with no advance whatsoever in range.

Rubbish.

(Ok, the sub-brake levers are quite interesting.


)

[scottg]

[quote="thelawnet"[snip]

You can't use the 46/30 chainsets with your existing 11-speed or 10-speed road bikes because of the different chainline.[snip]
Rubbish.[/quote]

If you have a rear 135oln bike, think Surly, Rivendell etc, the 10 speed crank will be OK, imho.
Now to figure out a nice 13-36 10s cassette.

I don't think that Shimano has the CTC in mind when they design their rubbish.

[NewHorizon]

The 46/30 will run with the 11-40 or 11-42 cassette using Di2. That's the 'rubbish' I'll be putting on my bike. I don't understand the negativity towards Shimano, even the basic stuff does the job and the better stuff does it very well indeed.

[thelawnet]

The 46/30 will run with the 11-40 or 11-42 cassette using Di2. That's the 'rubbish' I'll be putting on my bike.

No it won't.

With Di2 you've either got a 1x dinner plate, or a 2x 11-34. Same as the non-Di2. Not 2x dinner plate.

[NewHorizon]

If I select Di2 11 speed on the Shimano GRX interactive matrix, those are the components that are listed, hence my reasonable conclusion that it will work.

[thelawnet]

If I select Di2 11 speed on the Shimano GRX interactive matrix, those are the components that are listed, hence my reasonable conclusion that it will work.

That's not a very reasonable conclusion.

This is the 1x Di2 derailleur:

https://bike.shimano.com/en-US/product/ ... RX817.html

At the top it says 41t capacity.

At the bottom it says 31t (the correct figure is 31t).

This is the 2x Di2 derailleur

https://bike.shimano.com/en-US/product/ ... RX815.html

It says at the top 42t, and at the bottom 38t, while the numbers in the middle represent a 40t capacity.

At any rate, there is no suggestion your 45/47t capacity is viable.

(I'm not going to say it definitely won't work, but they are not claiming it will.)

[iandriver]

I don't understand the negativity towards Shimano, even the basic stuff does the job and the better stuff does it very well indeed.

It's the lack of cross compatibility rather than the functionality of any complete groupset that is the frustration. They are all as bad for it.
Another lot of chain lines etc. Chainsets that needs a specific mech.

Anyone seen any mention of the BCDs on those chainsets? Or is it like SRAM, is a 30t the smallest you can fit.

Edit, answered myself, looks like 80mm inner, so down to a 26t perhaps.

[NewHorizon]

If I select Di2 11 speed on the Shimano GRX interactive matrix, those are the components that are listed, hence my reasonable conclusion that it will work.

That's not a very reasonable conclusion.

((edit))

(I'm not going to say it definitely won't work, but they are not claiming it will.)

Hmm, you could be right, that's a bit rubbish . Still, there's always a Wolf Tooth hanger to fall back on.

[andrew_s]

Anyone seen any mention of the BCDs on those chainsets? Or is it like SRAM, is a 30t the smallest you can fit.

Edit, answered myself, looks like 80mm inner, so down to a 26t perhaps.

It's got wonky spider arms (i.e. 4, not at 90° to each other), so getting hold of chainrings other than those Mr Shimano sees fit to supply is likely to be difficult.

[iandriver]

Anyone seen any mention of the BCDs on those chainsets? Or is it like SRAM, is a 30t the smallest you can fit.

Edit, answered myself, looks like 80mm inner, so down to a 26t perhaps.

It's got wonky spider arms (i.e. 4, not at 90° to each other), so getting hold of chainrings other than those Mr Shimano sees fit to supply is likely to be difficult.

Good spot. Another thumbs down