Nerding out: gravel gears for Florida / one bike or two

I’ve only been cycling for just over a year, so there’s still much I don’t know. And my nature is to dig into “how it works” to understand it, so I can make better choices. Bear with me as I make a mountain out of a molehill here… this is how I learn.

The questions are simple:

  1. For recreational gravel riding in flat Florida, how low a gear ratio am I likely to need?

  2. Which of the available gearing options would you recommend, and can you point to any specific pros/cons?

In the chart, on the left in gray are the gears and ratios for my Synapse. In orange is the range of gears where I spend most of my time. In yellow are the two gearing options available for the Diverge. And in white are the three 2x options I could create on the Diverge using SRAM Force AXS components.

Chart note: In the 2x columns, I eliminated all the gear ratios from the smaller chainring that would be redundant to another in the big ring. So 24 possible gears become 15 viable ratios… 3-4 from the small ring and the rest from the big ring.


For background: I’m 48, 225 lbs, roughly 2W/kg, usually on the road at around 27 kph (~16.5 mph) – so very much a MAMIL – trying to get faster and get in better shape by cycling. I only ride on the road right now, on a 2018 Cannondale Synapse Hi-Mod Red eTap, and I generally buy one nice thing then keep it for a long time. So I’d like to buy a really nice gravel bike (2021 Specialized Diverge), but I’m trying to understand and define which drivetrain components I should get.

Based on my experience with the Synapse, I’m in love with eTap and would love to stick with SRAM electronic shifting. The Shimano in yellow is still in consideration because it’s $1900 cheaper than the factory SRAM option, and maybe I should just keep the change. :grin:

My current thinking is that the ideal setup is the second white one: 46/33 up front, 10-36 in the back. All the speed of my Synapse (not that I’m strong enough to use it yet!), a MUCH lower gear at the low end (0.92x versus my current 1.06x), and smaller steps between gears.

BUT… should I maybe just leave the 1x SRAM Force AXS setup I get from Specialized (second yellow) in peace? How much more reliable is 1x? How big a deal is it really to have that super-low gear when my state (especially around Miami) is flat as a pancake?

Seems to me my techie, gadget-loving brain wants all the theoretical benefits of the SRAM 2x12 option… but that’ll cost about $7500 total. Just keeping the SRAM 1x12 saves me nearly a thousand bucks at $6700. As for the Shimano, it costs me quite a bit on the top end… but the bike then costs $4800 and I’m not that fast (yet!) anyway. Maybe I should just be happy that I’ve got a cheaper option? Am I likely to be able to outgrow it within the next 4-5 years?

Budget note: I can afford this comfortably, but I try to be responsible with money. I’m trying to make the “right choice” here: quality and fun that will last me a long time, without needing to upgrade as I grow faster and stronger, but without overbuying and just wasting money.

Yes, I’m massively overthinking this. :grin:

Which setup, and why?

Do you plan on riding in any places other than Florida - say on a vacation trip to somewhere hilly? If you plan on riding any hills, I’d say you’ll need an easier gear than any of the white options. And the only one of these that would work is the SRAM Eagle.

If you plan to just ride on flat trails in Florida where you’ll neither use the top end or bottom end, then pretty much any of those options could work.

But I’d probably pick one of the 2x options to get closer gear spacing. Probably the last white column - 10-33 cassette so closer spacing than the 10-36, while also having a 30-33 easy gear just in case you need it.

I have the 2021 diverge comp carbon with 48-31 rings, 11-34 cassette. I live in Colorado and ride a lot of hills. The 31-34 is just about easy enough. The diverge is a great bike. The future shock is awesome, and it can fit big 50mm tires - really smooths out trail roughness.

One other thing - I don’t think a 1x is necessary on a gravel bike, as you just don’t shift enough to make it necessary. On MTB or cyclocross, I wouldn’t ride anything other than 1x.

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Just because you’re in Florida, doesn’t mean you don’t need low gearing. You’ll hit mud, terrain, tall grass fields, as well as steep flood control berms. Just gear for the lowest speed you need and take what you can get on the top end. You probably don’t need a 1:1 gear unless this is a travel bike, so I’d look at a 34 or 36t cassette, allowing you to run normal freehubs on your wheels/trainer.
I run 1x 42 / 11-36 in flat Illinois. That’s good for 7mph - 31mph with my wider cadence range. The only downside is that you tend to use the smaller cogs more often.

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I’m not sure I understand what you’re saying here. Maybe a typo, and you meant to say you don’t think a 2x is necessary on gravel?

OK… so how low is low enough for mud, berms, and steep bridges? Is something like 30-33 (0.91x) low enough, or do I need to look at something like 30-36 (0.83x) to be sure? If I’m going with a white option (all of which are SRAM Force AXS 2x), I can do either one and they all provide sufficient top end.

I think I’m going to toss out the Shimano option, and narrow down my choices to SRAM 1x or 2x. If I had to make a gut call right now, I’d say that my best choices seem to be 42/10-50 or 43-30/10-33. Reliability and simplicity versus smaller steps between gears.

Interesting that a 24-gear setup (2x12) really gives you only 15 distinctly different gears…

Sorry - I should have clarified.

The benefit of 1x is simplicity and reliability - less dropped chains; one less mechanical device (front derailleur) to break; less cognitive load needed to shift when on the limit; etc.

These benefits are most evident in MTB and cyclocross where you are generally shifting a lot. On gravel rides, You don’t shift anywhere near as frequently, hence these benefits are less meaningful.

The downside of 1x is bigger steps between the gears. I think this downside is most evident on road and gravel rides where you are often spinning at a steady cadence, and finding the “right” cadence with 1x can be more difficult.

IMO, gravel riding, like road, is better suited to closer gear ratios hence a 2x.

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.91 = you can climb Haleakala… off the pavement,… straight up…against the wind… if you can keep the bike from falling over sideways or backwards. This is the gearing MTBs have for climbing steep muddy inclines.

1x 42 or 40 - 11x36 should be good in Florida . I’d only go 2x here if you’re going to Georgia for some hill or want to faster group rides on road tires. 1.10 (40-36) is a pretty really steep hill even for a clydesdale.

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32-50 is a common granny gear on MTB. That’s a 0.64 ratio - a whole lot easier than 0.91.

For a Clydesdale on 7-8% road grades, I’d recommend 34-32 as a granny gear (1.06). On gravel, I’d go even easier e.g. like the GRX 31-34 (0.91).

Now of course, in flat FL these gears may not be necessary - but if riding hills, it’s nice to have the bailout gear when you want it.

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What is a “Clydesdale” in cycling-speak? I’ve seen it several places but don’t know the meaning.

I’m 50 pounds overweight, maybe 60 pounds, and just got off the couch (literally) a year ago. I’m getting stronger and faster, but I’ve got a long way to go. So far, 34-32 (1.06x) is still not easy enough for me to climb a sustained 7% grade… I can barely do a two-minute climb up a steep bridge at 7% because I’ve got good (for me) sprint power, but 290W for two minutes and I’m toast. :grimacing:

I think that, for reasonably fit cyclists, the SRAM Force AXS 1x setup (42/10-50) looks fine: 0.84x to 4.20x. What worries me is that, for-me-right-now, those are some very big steps between gears, and that’s why I’m wondering whether it’s a good investment to go 2x (43/30, 10-33 for example) so I can get 0.91x to 4.30x in smaller increments. The idea being basically to buy a bike that I can grow into, but makes my current efforts easier.

At the end, what I’m wondering is: is that a good strategy, or is fear/trepidation causing me to spend money that’s pretty much a waste and I should just buy the SRAM 1x Diverge and everything will work out?

New options chart:

In gray, my Synapse road bike. In yellow, stock Diverge 1x. In white, two 2x options depending on just how low I might need to go. If 0.91x is “fine” then the 10-33 cassette is great due to the smaller steps between gears. If I really should get something like 0.83x (30-36) to help me out for the first couple of years as I get stronger, then the 10-36 cassette might be just what the doctor ordered. Easy to change the cassette later on anyway.

It’s a loose term. Usually means someone over 200lbs. What really matters for climbing is w/kg however, not just weight.

If you want to nerd out even more :grin: - you can use the following websites to estimate your speed while climbing at a given power output, and your cadence at that speed given your gearing:

Speed on a climb based on your power and weight:

http://bikecalculator.com/

Cadence at a given speed based on your gearing:

You can then check that at a sustainable climbing power for you, your cadence will be acceptable give your gearing.

Eg if your implied climbing speed resulted in a 40 rpm cadence, that may be too low for comfort.

This depends on your comfort level with cadences outside your preferred range. For me, I prefer 2x for road and gravel as it more easily allows me to find that right cadence. On my MTB with 1x, finding the “right” cadence is less of an issue because cadence is changing all the time anyway as the trail undulates.

You could get the Diverge Comp Carbon with mechanical shifting for $3800. 48-31 rings; 31-34 cassette. This is the bike I have. The shifting is super crisp.

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Also…
not all Florida is flat.
There are portions in the middle that are rolling hills.

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You’re right. I’m in Miami, so near me is all flat. And while I don’t expect to take my bike to Colorado, mid-Florida is more reasonable and should be considered.

Sounds about how I feel, I guess in large part because I don’t yet have a very broad cadence envelope anyway… mostly 90rpm to 105rpm, dipping down to about 80rpm at need. Lots of room for improvement.

How did you get your hands on it this quickly? I’m told the Pro Carbon I was looking at is backordered until nearly Christmas. I’ve added your option to my chart at the far right:

Because of the 17-tooth difference between the front chainrings, you get a greater number of usable gears on the low end, with smaller steps between them.

I’ll nerd out even further on gear ratios later. An odd question just struck me:

I had thought the gravel bike wouldn’t be very good on the road. But looking at these gear ratios, they’re a LOT more similar (in/near the orange part) to what I use most on my Synapse. If I get a Diverge with one of the white drivetrains, and I get an extra wheelset with 28mm tires on them for the road… how well does that Diverge compete against my Synapse for a “Clydesdale” trying to comfortably do 3-4 hour rides?

In the long term, if I want a two-bike solution to road and gravel… are those two bikes a Synapse and a Diverge with lower gearing, or a Diverge with all-rounder flexible gearing and then eventually a SystemSix for speed on the road?

I started looking the day they were released. I found a bike shop in Boulder that had one in stock and bought over the phone. Picked it up a few days later. Within a week, I think initial stock in most shops had sold out.

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I’ve thought about selling my road bike and just using my Diverge for road. But I’d probably get less than half what I paid for it. So I’ll probably keep it and use it for the trainer and the couple of months in the spring where road riding is only riding here.

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Understand your point perfectly. In my case, I got a Synapse because even on an “endurance” geometry I can’t yet get down to the drops for more than 60 seconds (and that’s after a year of riding). I wanted the most comfortable road bike I could get because it’s really my “training wheels” as I learn cycling, get into shape, and slowly lose the 60 pounds of extra weight I’m carrying. The Synapse has been great for that, and I have loved the electronic shifting.

So it occurred to me to wonder how closely a Diverge would compare to my Synapse on the road, if I set it up with a similar drivetrain (SRAM Force AXS 2x) and added a road wheelset with 28mm tires like the ones I’m currently riding (pretty much as wide as a 2018 Synapse can take). Clearly it would be more comfortable – but is there a downside? A significant speed penalty? Anything else that I, due to inexperience, have not considered or might not know about?

I got my Synapse new, but as a prior-year model, for just $5K, roughly half its MSRP. I could probably sell it for 75% of what I paid. But does that argue for keeping the bike, because I got such a great deal on it and it’s sufficiently different from the Diverge? Or does that argue for recovering most of my money, moving to the Diverge as my only bike with separate road/gravel wheelsets? I also don’t need a trainer bike… just bought a StagesBike for indoor training.

I’m not an N+1 guy… I want to have the right tool/tools for the job, that’s all. Hence my question about whether I need a Synapse and a Diverge, or whether the Diverge can be a great one-bike solution to my current needs.

.64? That’s about 3.5mph at a constant climbing cadence. Are you going up a 25% incline? You probably ought to get off the bike at this point. :slight_smile: You’d have to be going up a steep, rocky slope to need that, and you should probably be on a MTB at that point.
Minor note- keep in mind there’s a ~5%gearing difference between a Gravel tire and a MTB tires, so that’s like a 32-48

BlockquoteWhat is a “Clydesdale” in cycling-speak? I’ve seen it several places but don’t know the meaning.

Anything over 3% body fat in cycling. Really, you start finding parts that you’re overweight for around 175lb (titanium pedal spindles & 16spoke wheelsets).

Blockquote I had thought the gravel bike wouldn’t be very good on the road. But looking at these gear ratios, they’re a LOT more similar (in/near the orange part) to what I use most on my Synapse. If I get a Diverge with one of the white drivetrains, and I get an extra wheelset with 28mm tires on them for the road… how well does that Diverge compete against my Synapse for a “Clydesdale” trying to comfortably do 3-4 hour rides?

It’ll be absolutely fine on the road. The major difference between the Synapse and the Diverge’s geometry is that the Diverge adds 15mm to the length of the frame and takes 15mm out of the stem. This give you more room to run a bigger front tire without hitting your foot, but costs you some ability to draft in a group road ride.


There are a few other details that matter ,but not much. The Diverge has the rear wheel 15mm further back, which changes the pivot point when you turn. My Checkpoint can adjust this dimension by 15mm, and I couldn’t tell the difference.
I’ve got a current Emonda ALR road bike and a Checkpoint SL gravel bike - both equipped about the same except for the chainring (1x / same fit /same grade stuff in general), with three sets of wheels/tires (gravel 38c, wide road 30c, and road 25/28c on similar wheelsets). I can’t really tell the difference in handling between the gravel and road bike, prefer to do the longer rides on the gravel bike (for the fatter tires), and only really need to grab the road bike for when the AM group ride is going over 25mph+ sustained. There’s not really a compromise.
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What I’m understanding from your post is that a Diverge with a similar drivetrain and similar wheels/tires to what I currently have on my Synapse would be (a) more comfortable for me and (b) would not incur any real speed penalty, and thus I’d be better off selling my Synapse and putting the money into a well-equipped Diverge with multiple wheelsets for the next few years as I keep improving.

  1. Am I understanding you correctly?
  2. Is there any way I can try to quantify the speed penalty, if any?
  3. Why does 15mm more frame and 15mm less stem “cost you some ability to draft in a group ride”?

Yeah - I should have clarified, my post above was indeed referencing MTB gearing for MTB. Not implying you’d want 32-50 on a gravel bike.

I have 31-34 for the easy gear on my gravel bike, and that’s good for pretty much everything that I ride. I even rode up some single track on it a few weeks back (PR’d a 40 minute climb in fact!).

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