1x gravel gearing suggestions
 

My gravel bike currently has 42 tooth chainring up front and cassette is 11-42. Is anybody doing something like 38 or 40 up front and 11-42 in back. If so, how do you like it?

where I ride it’s pretty rare that I actually need the smallest cog in the rear especially since on gravel downhills I’m more conservative so I’m not blasting down them anyway.

what I do find is certainly I wouldn’t mind some easier climbing gears occasionally? I know for my very long rides and long events I’m not needing top end speed anyway.

just curious what others are doing.

My bike came with 1x 40t chainring and 11x42 cassette. I may size down to a 38 or so as I plan some pretty big rides for me this year. Haven't got to get out much yet to see how well the current setup works for me.

I'm currently on a 40t chainring and 11-42 cassette as well. It was previously a 40t with 11-36 but I didn't have enough gears to climb the local MTB trails.

So far, I've been going up and around 12%+ gradients on dry/hard pack without an issue. Taking it on the road, the 40x11 is enough to keep me moving at 25MPH at a 90RPM cadence.

40T in the front, 11-46T rear with Apex rear derailer

I've run 38 x 11-36 and I found the lack of top end to be very annoying. I don't think you need to be bombing to want a bit more gear at the top end. When things get gnarly, you aren't pedaling anyway. On long, non-technical slopes at shallow to moderate grades, it can be frustrating to be limited. I raced that same cassette with a 42 ring a couple summers back and even that wasn't quite enough on the last descent of that course. But that's where the trade-offs of running 1x come into play. Having a low gear of 44x36 would've been worse over the whole course than I would've gained with 44x11 on that last descent.

That said, chainrings are cheap and can be swapped in and out very easily without messing with your drivetrain setup. So if you think losing a bit of top end won't trouble you, I would just pick one up and try it out.

Thanks for the tips all. Think I’ll try a 40t chainring and see how that feels

Good comments here, but if the 42 is too high going to a 40 is not enough of a change, go 38 and if that was too far (unlikely) go back to 40 as rings are cheap.

I have a 40t on one of my bikes. I run it with an 11-34. 40/11 leaves me wanting a bit more top end in situations where I have a nice tailwind, or am riding in a draft with others.

I have another 1x bike with 42t and prefer that size, although according to the calculator it doesn't make that big of a difference.

With 700x32mm:
38/11 @ 100rpm = 27.72mph
40/11 @ 100rpm = 29.25mph
42/11 @ 100rpm = 30.69mph

Assuming you cannot easily run something larger than an 11-42 rear cassette size, dropping your front ring down to a 40 or 38 will give you lower gearing without sacrificing a whole lot on the top end.

Your next challenge will be finding a place to buy a new chainring that actually has them in stock.

I would go with a 36 or 38. if you want more climbing gear and top speed is already not a issue.

I’m definitely going to at 38t as well.

I have two 1x gravel bikes. My Cutthroat has a 34T chainring and a 42-11 cassette. It climbs well here in the western NC mountains, but spins out if I ride on the road.
My Grail has a 42T chainring and a 50-10 Eagle cassette. Climbs great, never spins out, even on the road with slicks. Awesome drivetrain, truly the only drivetrain I’d ever need. Drawback, it’s expensive. If i could afford it, I’d duplicate it on my cutthroat.

Crank arm length will always impact your gearing and how much leverage you have over said gearing, including the fluidity of your cadence.

Really depends on how you ride. I have 36 front, 11-42 11-speed rear; the friend I ride with most regularly has 34 front, 11-42 11-speed rear. We spin out pedaling down hills - but we don’t care to hammer downhill anyway.

My drivetrain (Shimano XT) could also handle an 11-46 cassette, so that might be an option for you too.

I have different wheelsets with 11-42 cassettes so plan to just keep those. I don’t worry so much about hammering downhills especially if I’m doing long events where I’m not hammering it anyway

Mine came 40 tooth chainring and 11-42 (Shimano GRX). Went down to a wolftooth 38 tooth chainring which helped quite a bit.

I took the 11 and 13 cogs off an 11-36 10 speed and added a 42t cog and a 13t IRD threaded first cog and am running 13-42 10 speed with a 48t chainring on a Giant revel hardtail does everything I need riding the gravel and tarmac here in Cambodia. I also have a modified hybrid with a 46t chainring and 12x36 9 speed cassette. Both of these do well here. Most of my rides are relatively flat but lots of dust and bb sized pebbles.

Same setup here, although I'm running Microshift which I like a lot. The 46 gets me up the 12% grades when traction isn't great, and I can cruise the 40x11 when speed is needed on the flats.

40T and 11-42 for me. It works great for the riding I do, which includes a fair amount of MTB worthy singletrack. I also bought a 42T chainring, thinking that I would miss the top end, but I honestly haven't felt the need to switch it out.

Looking at a gear calculator for a bike with with 40mm tires - and just as an example, if you are tackling a steep trail at about 5mph in your 40/42, your cadence will be about 65rpm. For your cadence to be at 75rpm for the same speed you would need a 34T chainring.

I have 36 front, 11 speed 11-42 rear (650b X 48mm). The person I ride with most has 34 front, 11-42 rear. No, we can't bomb downhill, but basically above 30mph we're not interested in pedaling anyway.

I've been happy with my gearing, even bikepacking in hilly VT. Your experience may vary, of course! And I'm considering 34 front, and/or 11-46 rear, on future hilly bikepacking to have a little more flexibility.

Interesting thread. I need some advice myself. I recently bought a nice (slightly) used gravel bike that came with 36T front and a 9-46 rear on 650b wheels with 47mm tires. (In case you are wondering about the 9-46, it's made by e*Thirteen.) The bike has SRAM Rival 11-speed shifters. I ride a lot of long uphills with some pretty steep sections, and even with this configuration I feel like I wouldn't mind a lower gear to be able to raise my cadence.

The seller also threw in the original wheels that came with the bike, which are 700c. I'm going to mount 42mm slicker Rene Herse tires on them for rides that have more pavement and easier gravel. I'm trying to figure out what kind of cassette to put on these wheels.

The other factor is that the bike has an Easton crankset with the Cinch system that makes it very easy to swap chainrings. I already bought a Wolftooth 32T chainring to use for steeper rides, but then I found out the chain was too long and I didn't want to mess around with it until I figure out what I'm doing with the second wheelset.

So, here's the question: what cassette should I buy for the second wheelset that is slightly more road oriented but can still climb big hills, and is there a way that I will be able to mix and match wheels and front chainrings depending on what ride I'm doing without having to re-size the chain?

First off, find what sort of diameter tires your bike was designed for. Whether you stick to 650b or 700c you want to stay close to that diameter, although you can deviate a little bit.

if you for example, use your 32t ring in the front, but use something with less than 42t for the rear cassette, you likely wouldn't need to resize the chain. All depends on how much you're choosing to deviate from whatever setup youve got now.

It's an Ibis Hakka MX. It's made to work with either 650b or 700c. The bike originally came with Ibis 700c carbon rims and I already bought a set of 42mm Rene Herse Snoqualmie Pass tires, which are supposed to be gravel rideable, but they are pretty slick and supple and good for pavement. The guy I bought it from never used those wheels and replaced them with Enve G27 650b wheels with WTB Venture 47mm tires. I have a road bike already, but since I have the 2 wheelsets for the gravel bike, I'd like to have two different setups depending on the ride I'm going on. However, all of the configurations need to be able to climb big hills.

Mine came with 42T and it was OK on Tarmac but of off road hill, it was not great. I tried 40T and it was better but the difference was not significant so I move to 38T which is good I only got stuck once on a 15% Mtb trial (muddy wet rocky...). It did not bother me much, getting stuck and forced to push 50m over a 80km MTB ride, I can leave with that... but I know that I would had done in with a 34 or 36 as I get through it in dry conditions.
I had to change my chain was the supplier sent a chain which was 1 linkset too short :( as the a 36T chainring is cheaper than another chain I fitted a 36T ring.
Compared to a 42T, the 36T x 10-42T is equivalent to 42T x 12-49T. As I very rarely use le 10T, I figured out that if I loose the bearly used hardest gear (42x10T) to get something like a a eagle (42x50T) cog, it is beneficial for me.

I love these threads. Gearing is so personal. I use a 46T chainring with a 10-42 cassette. I do have a 42t I swap in for some rides. And I have found that fro me the gradient isn’t the issue, ever, it’s the surface condition.