Using Gravel Setup for Road? Help me Choose a Bike with Electronic Shifting

Equipment
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Hey everyone,

I’m considering getting a new gravel bike equipped with electronic shifting. My main reason for this is to have a frame with the widest tire clearance possible, allowing me to explore more off-road terrain. However, I also do a significant amount of road riding. Fortunately, I have a spare wheelset with road tires that I can swap out when I want to hit the pavement.

I’ve found an affordable gravel bike with electronic shifting, featuring a SRAM Apex AXS groupset. During a test ride on city roads, I honestly couldn’t find much difference compared to my current 11-speed Shimano road groupset which has a 50T chainring on the front. This Apex setup has a 40T chainring up front and a 12-speed 11-44T cassette, with a single chainring configuration.

Here are a couple of considerations:

  • I plan to participate in various events this year, including road races, crits, cyclocross, and gravel rides, but I only have a budget for one bike.
  • My concern is whether I might “spin out” of gears during fast road rides. I felt like I was able to spin faster on the hardest gear during today’s test ride when descending a -2% grade.

During the test ride, I didn’t have a power meter. Has anyone here used the APEX AXS groupset on the road or during fast group rides? How does it perform?

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I ran into a similar dilemma when building my “groad” bike. In my opinion, Sram XPLR is great if you have a designated bike for gravel and one for road. However, it can also be an alright allrounder, but you have to be willing to sacrifice some range. One thing that you could do is buy a few different size chainrings if you do get XPLR and play around with the gear ratios (swapping chainrings for road and gravel). Before buying I would recommend looking back at your rides and seeing what type of speeds you typically ride at. I would then go to an online gear ration calculator such as Bicycle Gear Speed Table | BikeCalc, play around with it, and see what you would need for your everyday riding. The issue that I ran into with the XPLR groupset was that it did not cover the range of riding I do (I live in the mountains so I regularly encounter steep chunky gravel climbs when gravel riding and fast road descents when road riding with a group). Hope this helps a little.

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You will absolutely find yourself lacking too end gears if you plan on doing crits, road races, etc. a 40x11 just isn’t enough gear.

You could have multiple chainrings available, which are relatively easy to change, but then you’ll probably also need an extra chain to go with the larger CR option.

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How competitive are you in all those different types of cycling events? The gearing is so different. The bike geometry is also so different.

New endurance road bikes can take large tires. The Roubaix takes 38mm.

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I’d say the only way to get away with this is by going 2x. (or chainring swaps as suggested by @Power13)

I tried similar with 40t and found myself spinning out 40-11 too often on my road wheels when I was riding on my own without even a social group, let alone a competitive one. I had enough gearing for my gravel wheels on road, but that wheelset had a 10t cog, 40c tires make for a bit bigger gearing than 28c, and the rolling and aero penalty of the gravel tires probably also kept my speeds a tiny bit lower. At the low end of the gearing spectrum I also really needed lower than 1:1 for my bottom gravel gear, so 40-42 was fine but when I briefly had a 42t ring on that bike I kept having to mash too slow a cadence up the steepest bits of gravel.

I rebuilt the bike with 2x 48/31 and 11-34 for gravel and 11-30 for road. It makes an amazing endurance road bike and it’s often the bike I choose for really long road rides or really climby road rides where I want to be kind to my knees. I can ride it comfortably in a pacey group, but I have to spin pretty quick if ‘pacey’ steps up to ‘racey’.

The bike itself would be useable in a crit, though I’d be aware I’m sacrificing something in the cornering and handling. Certainly in the lower level categories it wouldn’t be enough of a disadvantage to make it a major issue though. It could still do pretty well and I could still learn and develop a lot on it.

The 48-11 top gear would be the main issue for me, even in a Cat 4/5 crit. I find even 50-11 is on the edge of being limiting in some lower level courses/fields. That’s coming from a rider who is 3.75-4w/kg and 70-73kg depending on time of year, with a preferred cadence between 95-107rpm for hard efforts.

I think you can get more range out of SRAM 2x groupsets than you can out of Shimano (which is what I’m describing above). If you put some Rival parts on it you could get to 48/35 with a 10-36 which would just about do it. Seems like that would be a lot more expensive than just having multiple chainrings and chains but would be the only way to do it without having to swap anything more than wheelsets.

105di2 can do 50/34 with 11-36 now, and since that’s even more range than my current GRX groupset I think that’s how I’d rebuild my gravel bike if I had to do it again today. No clutch, but that doesn’t matter so much with 2x anyway. As it stands, it looks like 12s GRX di2 will get launched this year though so since my bike currently works for me I’m going to hold out for that groupset before making any more changes.

EDIT: just seen that @Clubs17 gave a link and some tips for this next bit - that’s a great place to start!
If you know your preferred cadences and likely racing speeds you can go to an online gear calculator to see what ratios might be like for you. I find it most helpful to see what speed I’d be going at 107rpm in my biggest gear (which is what I somehow always average in VO2 intervals), and what speed I’d be going at 85rpm in my smallest gear (which is about the lowest I want to do for a long seated climb).

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For a bit more range there is also the HELIX RACE 12-SPEED 9-45T GRAVEL CASSETTE.

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If you’re thinking of going the 1x with multiple chains/rings option then the discussion starting at about 30 mins in this episode of the Nero Show might be of interest: https://youtu.be/xd3wnyFLDHQ?si=2RSupkLFeBueY8oz&t=1779

Since I’m almost exclusively a Shimano customer I found that this was the first time I started to understand the SRAM 1x Road ecosystem properly. It’s probably pretty entry-level for anyone who already knows SRAM a decent bit though.

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2x should be your option if you plan on just swapping wheels. I ride 52/36 and 50/34 on my gravel bike depending on the season. wouldn’t have it any other way. I don’t currently race on the gravel bike on the road, but have done when travelling.

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Thanks for your inputs!!

In that case, I have another idea. I already have a used Shimano 105 Di2 groupset. I’m considering purchasing a more affordable gravel bike equipped with a mechanical groupset and then installing the 105 Di2 groupset onto it.

My main concern is that I haven’t found a road bike capable of accommodating tires larger than 40c. So, now that I have a Di2 groupset, I may explore fitting it onto a gravel bike to maximize tire clearance without limitations.

Unfortunately, for the bike I test rode, the mechanic cautioned me that it wouldn’t be safe to accommodate anything larger than a 44T chainring on the front, as doing so could risk damaging the frame.

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1x or 2x? Could be significantly different depending which. The big ring on 2x is much further outboard than most 1x rings.

Saying that, a friend just built up the new Revolt with 105di2 and said the 50 wouldn’t clear. He did manage to dial the limits on the front mech enough to fit his 48/31 grx though.

If the bike you rode takes 2x I’d be surprised if it won’t clear at least 48. Would be weird to design a gravel bike that won’t clear one of the most common gravel groupsets on the market…

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It was a 1x drivetrain setup. I was also informed that a 2x drivetrain for SRAM Apex AXS wouldn’t be feasible because the rear derailleur is designed solely for a single chainring. If I needed a 2x, I would have to consider a bike equipped with a RIVAL groupset. Although the Apex serves as an entry-level electronic groupset, it’s not as easily upgradeable as I initially assumed.

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So just this week, the local shop built up a buddy’s bike with a 2x but using a SRAM MTB rear mech. He used a Force XPLR 44t cassette and it worked just fine.

So what SRAM says is technically feasible may not align with what is possible in the real world.

But note that if you tried it, you’ll definitely need to run a smaller cassette so that the RD has the wrap capacity for the chain and gear combos.

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Yeah sorry I was speaking in terms of fitting the 105di2 groupset you already have to that particular frameset, but I see now that the issue you raised about max44t chainring was more about the possibility of doing chainring swaps with the apex groupset.

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That is a point I wanted to make, but despite that, fitting a 105 di2 groupset wouldn’t be possible due to the chainring size limitation on the frame.

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Note that this combo is incompatible due to the chain differences between the Flattop and Eagle systems. So yeah it’ll work and shift, but the rollers will either not fit properly on the cassette or on the derailleur, depending which chain is being used, and the drivetrain will likely wear prematurely. You’re right that you can often get functional shifting, but for the most part these compatibility guides are there for a reason…

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What frame is it?

For many 2x systems on gravel bikes, the limiter for tire clearance is the FD. This is what led to the “wide” SRAM offerings, and to Shimano GRX, both of which shift the FD outboard a few mm. This is what you’d probably want to run a 2x system while maximizing tire clearance, and would also let you run a bigger front ring. Unfortunately that requires a different crank and a different FD than your standard 105.

To your original question: 1x can definitely work fine on the road, depending on your fitness and goals. Hell, Visma has run 1x on a bunch of hilly TdF stages. How hilly is your terrain? Do you really need a <1:1 ratio? A 10-44 cassette with a 44t front ring gets you a lot of high end and a 1:1 low gear, which might be all you need. And a 44:10 gear at 90rpm is over 30MPH.

Caveats: bigger steps between gears in the 1x setting, which can be annoying when riding in groups or pacing along on the flat. Also, the watt weenies will note that cross-chaining in 1x systems is super inefficient; if you spend a lot of time climbing in your 44:44 (with very high chain tension due to this being your big-big gear), you’re probably losing ~20 watts to drivetrain friction.

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Totally agree that 1x can be effective for road (including crits). While I have a 2x road bike, I do almost all of my road riding on my gravel bike with 1x. I typically run a 44 chainring and I used to switch between xplr 10/44 and eagle setup with 10/50. I’ve pretty much switched exclusively to the eagle setup, I just find very little downside to that setup vs. xplr (weight and gear jumps). I used to be the biggest cadence diva and would switch between 2x and 1x on my gravel bike, but after spending a bunch of time on 1x, I realized I didn’t even notice the gear jumps any more. I honestly think running 1x has made me a stronger cyclist with my ability to operate efficiently across a wider cadence.

All that said, there are some race situations where 1x can get you dropped. A strong tail wind with a slight downhill (ie still have to pedal) where you are doing high 30’s or faster for extended time can be tough. I find those situations rare even in racing, but it is a limitation.

Also, it sounds like the OP is running an 11/44 cassette, which adds to the challenge vs a 10/44 (and I’m assuming that hub won’t take an xdr cassette that’s needed for the 10).

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I don’t have Apex AXS, but gen-1 Force AXS. The electronic bits are to my knowledge identical to Force AXS v2 and Rival AXS. Which means, it is a great groupset.

Regarding gearing, 40:11 corresponds to 50:13, which is still plenty for a lot of rides. If you need more range, you can replace your 11–44 cassette by a 10–44 cassette (you will need to replace your freehub body, too, though). I know quite a few very fast people who used 40:11 gearing on the road. One of them was a former semi-pro who podiumed in a local race.

Honestly, I would focus more on climbing gears.

No, you are not sacrificing range with a 1x setup. A compact chainset coupled to a 11–32 cassette has a range of 420 %, SRAM’s 10–44 cassette offers 440 % range. Likewise, SRAM’s 10–36 cassette has 360 % range, very close to the 374 % offered by a compact chainset and a 11–28 cassette. A 10–52 cassette offers the same range as SRAM’s 2x gravel combo (43/30 chainset coupled to a 10–36 cassette).

What you need to decide is where you want to place that range, i. e. do you want more climbing gears or more overdrive gears? 1x is infinitely more flexible, the groupset can accommodate 38- to 54-tooth chainrings, more of you are willing to use MTB chainsets or third-party chainrings.

My tallest gear on my road bike is 42:10, which corresponds to 50:12. That’s great up to 62–65 km/h. At those speed, my bike points downhill and I would likely spin out any gear. Plus, on public roads I rarely want to go faster.

This.
I come from mountain biking where steps between gears have been naturally bigger. You simply get used to it. If you need to be within a 10 rpm window, I would recommend you try to widen the range of cadences at which you feel comfortable.

If I had to guess, I think cyclists who start out with 1x on the road, range no longer being an issue, they would be perfectly happy with 1x “road” groupsets.

In fact, in some applications, I welcome bigger gear steps, e. g. for climbing. I would also love a 9–36 cassette where the 10-tooth cog is replaced by a 9-tooth cog. The 10-tooth cog is almost always my overdrive gear, and at speed, I am usually between 42:15 and 42:12.

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How chunky and rocky is the terrain you want to ride off road? And are your gravel rides US-style endless long gravel roads?

I’m questioning a bit if you really want a frame with “the widest tyre clearance possible”. The issue with that is that it makes the wheelbase really long, but there are also downsides in aerodynamics, and often such bikes also have slacker head angles. Those are all things that you don’t really want if your main events are crits, road races, and cyclocross races. I’m wondering if you wouldn’t be able to compromise what you ride off road, and go for a bike with maybe up to a 38 or 40mm tyre.

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Plus I think you also have wheels already.

Note that you don’t have to buy a complete bike. It’s totally feasible to just buy a frame, and build it up yourself (or have a shop build it). Usually, you save on groupset costs when you buy a complete bike, because of OEM pricing, but if you already have that, buying a frame might work out cheaper. It’s maybe a bit more tricky to navigate the minefield of component compatability, but it’s also very satisfying to build a bike with exactly the parts you like.

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