GRX vs Ultegra 12 Speed

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gabpolitely
Posts: 24
Joined: Thu Sep 23, 2021 12:10 pm

by gabpolitely

I'm planning to build a gravel bike and I'm trying to make a decision on which groupset to put on it. For context I have the Ultegra 12 Speed on my road bike and I'd ideally like to be able to switch wheelsets between the road bike and the gravel bike.

Considering that the new Ultegra 12 speed has a gearing option of 50/34 and 11-34 (1:1 lowest), I was wondering if that would be enough for general road (70%) and gravel (30%) riding. I've also heard a lot of good things about the GRX hoods but I'm hesitant to go with GRX as it's currently only 11 speed and wouldn't be as compatible with my 12 speed road wheelset.

TL;DR: is 50/34 and 11-34 enough for gravel/all-road riding and is there a huge difference in control/experience between the GRX levers and Ultegra 12 speed levers.

Would love to hear your thoughts!

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ooo
Posts: 1590
Joined: Sat May 21, 2016 12:59 pm

by ooo

No, 1:1 is not enough.
Last edited by ooo on Thu May 12, 2022 9:49 am, edited 2 times in total.
'

CampagYOLO
Posts: 705
Joined: Thu May 06, 2021 3:58 pm

by CampagYOLO

The gearing is totally dependent on how fit you are and the terrain that you'll be riding on. Is there plenty of sharp inclines on the trails like there are on the ones I ride on? I personally like having lower than 1:1 for that kind of terrain.

There's quite a few rumours about 12 speed GRX coming out soon so it may be worth waiting to see what happens.

gabpolitely
Posts: 24
Joined: Thu Sep 23, 2021 12:10 pm

by gabpolitely

CampagYOLO wrote:
Thu May 12, 2022 9:47 am
The gearing is totally dependent on how fit you are and the terrain that you'll be riding on. Is there plenty of sharp inclines on the trails like there are on the ones I ride on? I personally like having lower than 1:1 for that kind of terrain.

There's quite a few rumours about 12 speed GRX coming out soon so it may be worth waiting to see what happens.
I see. Thanks! I was also toying with the idea of running a sub-compact Rotor 46-30 chainring if 1:1 wouldn't cut it.

I'm hopeful that 12 speed GRX would come out soon. That would instantly solve my dilemma. Do you have any links to leaks or talk of it doing so?

blaugrana
Posts: 457
Joined: Wed May 24, 2017 9:49 pm

by blaugrana

The 1:1 ratio might or might not be enough depending on what you do, but for me the deal breaker would be the lack of clutch on the Ultegra 12. After having used the GRX groupset there is just no way I would go back to a rattling drivetrain on an offroad bike.

Also this is very dependant on the type of riding you do (gravel means really different thing to different people), but I feel like the jumps on a 12 speed 11-34 cassette would maybe even be too small. In technical terrain sometimes things get very steep very quickly, and being able to switch to a significantly lower gear in 2 shifts instead of 3-4 is an advantage. But if you do relatively smooth gravel roads and no singletrack, then a more "road-like" gearing will surely be better.

LanceLegstrong
Posts: 1145
Joined: Fri Sep 13, 2019 1:35 pm

by LanceLegstrong

It really depends on where you live/ride. My first gravel bike was a Checkpoint with 50/34 and 11-34t and it was fine for the time I had it riding in central/northern NJ. Never needed lower than 1:1.

My setup right now is a GRX crankset 48/31 with 11-32t in the rear; I've never really needed lower than 1:1 as there's nothing that long or steep near me. I swapped to the GRX mainly for the increased clearance so I could put on a left sided power meter. With that in mind, maybe you could get the 12-sp FD to work with the GRX crankset even though it's not officially supported (outboard shift and smaller chainrings).
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CampagYOLO
Posts: 705
Joined: Thu May 06, 2021 3:58 pm

by CampagYOLO

blaugrana wrote:
Thu May 12, 2022 11:41 am
In technical terrain sometimes things get very steep very quickly, and being able to switch to a significantly lower gear in 2 shifts instead of 3-4 is an advantage.
In those situations I find 2x an advatage as a quick shift from big to small ring really helps.
Last edited by CampagYOLO on Thu May 12, 2022 12:33 pm, edited 1 time in total.

gorkypl
Posts: 529
Joined: Fri Sep 21, 2018 9:31 am
Location: Poland

by gorkypl

As a rule of thumb, you want to have 4-6 tooth less on front than in the back for general gravel usage - this including some climbs, riding with bags etc. This covers most of the spectrum, but obviously you can either live in a flat region or ride uphills with 20kg of cargo, which would require different gearing.

In my case, I was able to participate in fast gravel events (no load) and tour 2000km+ (fully loaded) with the same setup of 46/30 front and 11-36 in the back, never feeling I am lacking gears. I would definitely not want to have 1:1 as the easiest gear.

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gabpolitely
Posts: 24
Joined: Thu Sep 23, 2021 12:10 pm

by gabpolitely

Thanks for all the replies. I think I'll hold out until Q4 of this year to see what comes up (hopefully some 12sp GRX). After some consideration I think I'm better off running 46/30 and an 11-34 or the closest to that gearing that whatever the new GRX would offer. Thanks for the insights!

robertbb
Posts: 2179
Joined: Thu Jul 23, 2009 3:35 am

by robertbb

rea
gorkypl wrote:
Thu May 12, 2022 12:16 pm
As a rule of thumb, you want to have 4-6 tooth less on front than in the back for general gravel usage - this including some climbs, riding with bags etc. This covers most of the spectrum, but obviously you can either live in a flat region or ride uphills with 20kg of cargo, which would require different gearing.

In my case, I was able to participate in fast gravel events (no load) and tour 2000km+ (fully loaded) with the same setup of 46/30 front and 11-36 in the back, never feeling I am lacking gears. I would definitely not want to have 1:1 as the easiest gear.
Are you referring to 1x (or inner ring for 2x) and largest rear cog?

morrisond
Posts: 1325
Joined: Thu Mar 25, 2004 8:34 pm

by morrisond

gabpolitely wrote:
Thu May 12, 2022 11:11 am
CampagYOLO wrote:
Thu May 12, 2022 9:47 am
The gearing is totally dependent on how fit you are and the terrain that you'll be riding on. Is there plenty of sharp inclines on the trails like there are on the ones I ride on? I personally like having lower than 1:1 for that kind of terrain.

There's quite a few rumours about 12 speed GRX coming out soon so it may be worth waiting to see what happens.
I see. Thanks! I was also toying with the idea of running a sub-compact Rotor 46-30 chainring if 1:1 wouldn't cut it.

I'm hopeful that 12 speed GRX would come out soon. That would instantly solve my dilemma. Do you have any links to leaks or talk of it doing so?
It's next summer.

rothwem
Posts: 211
Joined: Wed Jul 09, 2014 4:45 pm
Location: Asheville, NC

by rothwem

CampagYOLO wrote:
Thu May 12, 2022 9:47 am
The gearing is totally dependent on how fit you are and the terrain that you'll be riding on.
And also what your preferred cadence range is. I live in a pretty mountainous area, and a 1:1 low gear is fine for me. I tend to ride a pretty low cadence (low 70s) when I'm climbing off-road though, I find that more pedal force puts more weight on my feet and less on my saddle and hands.

I think other factor is ride length--I rarely ride over 4 hours, so I could see if you were completely smoked at the end of ride needing lower gears.

jfranci3
Posts: 1572
Joined: Tue Jul 26, 2016 5:21 pm

by jfranci3

For travel, GRX all the way the incremental benefit of 1 gear in back isn't worth the gearing compromise. Adding a gear into the middle of 11sp 11-34 isn't that big of a deal. I just got my wife a Sora 9sp 11-34 and the gear jumps arent' that bad. True, having that extra gear on 40T+ cassette starts to make sense, but 12sp GRX is a year out and Mtb 12sp doesn't di2 yet.

If you're using one of the fork-off mini cases, I'd consider ultegra for the mechanical brakes w/ disconnnects. Wife's bike had TRP Spyre mechicanl disc, and they are VERY good. Way better than the BB7 & HY/RD i used. Having cables will save you time packing and unpacking whiling giving you more packaging options in your bag.


What kind of wheelset do you have? Some are pretty easy to R&R the freehub body. For example, DT swiss, I can swap cassettes in 10seconds, tool free - yank and plop.

gorkypl
Posts: 529
Joined: Fri Sep 21, 2018 9:31 am
Location: Poland

by gorkypl

robertbb wrote:
Mon May 16, 2022 2:04 am
gorkypl wrote:
Thu May 12, 2022 12:16 pm
As a rule of thumb, you want to have 4-6 tooth less on front than in the back for general gravel usage - this including some climbs, riding with bags etc.
Are you referring to 1x (or inner ring for 2x) and largest rear cog?
Correct - so something like 46/30 front with 34-36 as the largest cog in the back, or 38 front with 42-44 in the back.
I know 30x36 is different than 38x44, but this is just a rough estimate.

Fuji Cross 1.5 - Shimano 105 5800 | Cinelli Superstar Disc - Record 12s | Custom steel Karamba - Ekar 13s

by Weenie


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Tifosiphil
Posts: 359
Joined: Wed Nov 14, 2018 11:09 pm

by Tifosiphil

Going to ask a slightly off topic question in here as we have a lot of knowledge.

Running current generation GRX 810 with 11-34 rear and 52/36 front at the moment but have an everesting coming up in July. Been running this combo find in training but want a couple of spare gears on the day. Can anyone seen any potential issues with me sticking an 11-40 cassette on the rear and staying to just the inner chainring. 6 more than Shimano recommends but I've heard a lot of reports of it working. I won't be in the big chainring either so not too concerned about the capacity

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