daanbr78

Hello,

I am looking at buying a gravel bike but don’t quite know what would be best: getting S105 or GRX.



105:

• Shimano 105 R7000 2x11 Speed.
• Shimano 105 50-34T x 11-32T Gearing.

GRX:

• Shimano GRX 1x11 Speed.
• Shimano GRX 40T x 11-42T Gearing.

I live in The Netherlands. So pretty flat. I’d like to be albe to:

• join ride outs with road bike riders and keep up
• go onto rougher terrain with mountainbike friends
• ride road/Forrest/single track solo

On the road I’d like to not go much slower than right now on my (10 year old triathlon bike, average around 31 km/h).



105 would probalby be best in road ride outs, but does it perform on rough forrest/gravel terrain. Grx would be best in forrest/gravel but could I get up to around 30-32 km/h on average on road ride outs?



Many thanks in advance!



Kind regards

Daniel

Mmassey338

Why not the GRX 2x11?

daanbr78

the bike comes with either of the two mentioned group set configurations. Can only change to a 2x11 after bought

Badger6

The specified GRX group is definitely "gravel" oriented in it's gearing...the 105 is group is more versatile.

To help you understand the gearing of the two options check out this website. You can play with gear options and compare. The short answer is the specified GRX setup will be geared lower and you will not have as much "top end" on the road, the 105 setup (which is geared almost identically to what I ride on gravel), will give you a close enough top end on the road that you'll be able to keep up. I am on a 50-36 crank (due to chainring limitations of an older power meter), pushing an 11-speed 11-32 cassette. The 105 drivetrain will be a little lower than what I've got, but no higher, and I don't run out gear on a downhill until somewhere around 60km/h, I can easily stay with a group that is averaging 34-35km/h, and it has more than enough range to tackle anything pitching up that I want to ride from the Black Forest, to the Ardennes, to Wallonia. I think the 1x setup of the GRX would have you buying a front mech and new crank in a short time.

Rides4Beer

GRX 2x11

My 2019 Revolt has 105, and it's been great. My 2021 Revolt has GRX 2x11, and the shifters and clutched derailleur are fantastic. Def worth it, the clutched mech especially, even with a chainstay protector my 105 bike has gotten pretty beatup from offroad use. Not a peep from the chain with the clutch on the GRX setup. I use my Revolt as a road bike as well and def recommend 2x.

tdilf

2x

shoota 

40x11 will leave you wanting for more with the roadies.

msu2001la

Which version of GRX? There's 400, 600 and 800.
GRX600 is pretty similar to 105. Aside from gearing differences, the GRX rear derailleur has a clutch that can be switched on/off. This will definitely help with off-road riding to reduce chain drops and chain slap.

As for 1x, the 40x11 max gear is going to be fine for flat road riding at 18-20mph (30-32kph). I've done some pretty fast group road rides with a 40t 1x setup had no problem keeping up. Unless the group is hammering at 30mph+ or there are long descents, it's fine. I would worry more about the spacing between gears, as the 11-42 cassette has some pretty big jumps in it.

2x will be better for road riding, but I'd definitely take 1x for gravel, trails, off-road.

Rides4Beer

FWIW, the 600 level shifters are better than the r7000 105 shifters, imo, even tho they are technically the same level. The 800 series clutched RD is great, I'm just leaving the clutch on all the time, no chain slap when bunny hopping on the road.

mstateglfr 

I would get the 105 and change as needed. Itd be easier to change to make 105 a wider range drivetrain for what you want to do.

The stock 105 gearing may not be ideal for singletrack/mtb riding, but neither will the GRX. You will be short on easy gears either way.
I would swap stuff off the 105, sell it as new takeoff on ebay, and buy what works better.
Change the cassette to 11-36 and change the crank to Praxis 48/32(or something similar). Selling the takeoff parts will reduce the overall cost.
You will have drivetrain gearing that makes you feel like you won't be wanting more on the road and will be easier to spin on singletrack.

Elvo

I have Shimano R7000 with 48/32 crankset and 11-36T cassette and it works very well for all but the steepest gravel climbs

daanbr78

Many thanks to the many answers!

I will be making a decision soon.

JW in AK

I run a 105 2X with 50/34 up front and an Ultegra RX derailleur (has a clutch) driving an 11-34 R7000 cassette. So it's basically a complete 2X 105 setup with an upgraded rear mech. I use it as my regular commuter, on gravel/dirt/non-technical single track, and for bikepacking and haven't been disappointed with its performance. It's quick on the roads and gets me where I need to be even when loaded with camping gear. If you're up for changing the rear mech in order to get the advantages of a clutch and, as mstateglfr mentioned, selling off the original one, there should be minimal cost involved.

Badger6

Clutched RD is the key...they exist, there is no reason to not run one, in 2x or 1x setup. Concur!