Russ Roth

I've bent more cassettes (2) then snapped chains (1), somehow I don't feel chains are the weak link. Stuck mtb racing when the 34t is good but the next two down are bent over preventing the use of three gears made shifting fun.

Cheaper alternative, sram XO crankset with 42/26. Shimano shifters, grx front derailleur and Tiagra 4700 rear der. My touring/gravel bike is XO crank with 11-36 cassette and the rear der can run it. 19gi at the bottom, 102 at the top.

fourfa

I didn’t catch if the OP is switching to Di2 or mechanical. In Di2 you can lock out the big-big and small-small combinations, effectively reducing the range the rear derailleur needs to cover. I would never recommend this for a mechanical-shifting setup, as you’re inevitably going to forget and break something, but it’s probably OK in Di2. So then you should be good to go with a 16T front gap and whatever cassette you like in the rear.

FWIW I’m running mechanical shifting with 46/30 in front and 11-40 in back with the RX800 shifter, it’s over spec but safe. All stock, just a lot of B-screw (enough that I prefer to adjust it when I switch to the 10-36 on my road wheels). That’s 20.25 g.i., which is low enough for me for light touring on steeps.

rsrogers

I just put the 11-40t XT cassette on my Bianchi Allroad with 46/30 front rings. With the stock bracket axle unit the B-screw was all the way in and was hitting the tab at an angle. Probably perfectly safe, but not ideal. Replaced the stock bracket axle unit with a $20 Goat Link 10 and it was perfect. The b-screw is hardly turned in at all and it's flush on the tab. You are correct, that is some low gearing whenever it's needed (558% range!). Won't be in 30x40 very often, but likely more than I would be in the 46x11.

SquishyBiker

I found this when looking for similar combinations - essentially you can probably run a 11-40t comfortably on GRX 11sp:

deaninkl

I totally agree with the OP that Gravel bikes in general are to highly geared to be serious offroad for anyone but whipets or iron men.. however it is getting better with GRX and Sram offerings aimed at the sector. As more olders and fatties (both for me) see gravel bikes as all rounders I think it will get even better.

GRX400, 600 and 800 group sets state a max of 11-36 on the back, but as the post abve mine and several other souces state (my LBS confirmed also) than 11-40 cassette fits all GRX RD's with only some adjustment with the B screw. I have just bought a Silex 200 as I couldnt get a 400 (the 400 comes with GRX) the Silex 200 come with a Sora 48/32 on the front and a 11-34 at the back, I changed out (cheaply) the gearrings to 46/30 and an 11-36 will fit the back if I need it... so I's down to 24 - 114 gear inches the 11-36 cassette would take me to 22 gear inches at the low end. For hilly road use that is pretty much perfect, but so far I have not needed to get into my lowest geraing so am holding off on the 11-36 cassette swop.

Caliper

Get SRAM 10 speed. The cable pull ratio on road and mountain was the same for those setups ("Exact Actuation", or 1:1). Pair that with a 42/28 mountain crank and either a 11-36 or 11-42 cassette. I have a drop bar 29er with this exact setup and it's been running great for years now. (Apex road shifters and an X9 mountain deraileur). The 11-42 cassette will get you a spread from 105 to 18.4 gear inches.

mstateglfr 

A gravel bike is a bike that was designed to be ridden on roads. Gravel roads, but roads nonetheless. Riding them offroad creates unique challenges for gearing since you are asking it to do what a mountain bike does, without mountain bike gearing.
it's like complaining thst a Corvette sucks for going muddin.

A road bike with 34/28 gearing(typical road bailout gearing) on 28mm tires equals 32.30 gear inches.
A gravel bike with 34/28 gearing on 43mm tires equals 33.63 gear inches.

Basically it's a 4.1% gear inch difference due to tire width when considering common sized road and gravel tires. Add in 10% additional difficulty due to the surface being unpaved(which is pretty hardly conservative) and you have a 14.1% difference in effective gear inches.

So if you could climb a road with 34/28 on a road bike in 28mm tires, then 34/36 on a gravel bike with 42mm tires should get you up the same hill if it were unpaved.
When you add in even smaller front rings, you actually get even easier gearing for gravel.



Clearly everyone is unique in strength, capability, limitations, etc. I am not suggesting everyone should stfu and just accept gearing from 2014.
But at the same time, I do think it is valid to see that current gravel gear ranges are relatively wide for the intended purpose- to ride gravel roads.
If someone is looking to ride their gravel bike offroad, then the gearing may be lacking since the bike most likely wasn't designed to be ridden offroad.

jonathanf2

On my alloy bike, I'm running the GRX 10 speed 46:30t front crankset/rear derailleur and an 11-42t cassette + GoatLink. I can also clear big/big if I accidentally shift there, but I never use it. I use this setup so I can road ride to the steep trails and rough dirt fire roads/single track mainly reserved for MTB'ers. Though I ended up building a lightweight gravel bike with carbon frame/wheels and Shimano 105 + a lightweight 11-32t cassette which handles the paved fire roads and smoother dirt trails. Honestly, I prefer the smoother in-spec shifting of my 105 carbon bike, but my GRX bike with 11-42t cassette can ride where other gravel bikes will struggle.