Help me build a gravel bike!

Core question: I’m thinking about building an Open U.P. or U.P.P.E.R. with SRAM Red AXS for gravel around Miami, Florida. Two wheelsets, one for road and one for gravel. What wheels, tires, and other components would you recommend? What should I be thinking about or careful about? This would be my first build. Thanks!

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All the gory detail: Please help me choose, or build, my gravel bike. I have a fairly high budget available, so this should be fun. I’ll try to be brief with background, but ask for anything I forgot to include. And most of all, thanks for taking the time to offer your thoughts and input.

I’m 48, 5’7" (170cm), 222 lbs (101kg). FTP 195W, just started riding a year ago and have fallen in love with cycling. I own two bikes: a 2018 Cannondale Synapse High-Mod Red eTap, and a 2020 Specialized Epic Hardtail. At least for now, I’m far more comfortable on the Synapse, though I look forward to spending more time on the hardtail as I get fitter and lose some weight.

Important point: I’m in Miami, Florida, so everything is flat as a pancake (the only “hills” are bridges!). And while I’m working hard to get more fit and ride faster, I’m doing so purely for the pleasure of it. I don’t race, and have no one to please but myself.

My three gravel options are a Cannondale Topstone, a Specialized Diverge, or a build-my-own Open U.P. or U.P.P.E.R. Approximate budget is $6K to $7K, but I focus on getting good value (bang for the buck), so I’ll spend more if it seems to be worth the investment, or spend less if that’s the right decision. Hopefully this bike will become my new favorite bike… love the Synapse, hate dealing with cars and traffic.

All opinions/thoughts welcome, but my real questions here are all about the Open build. If I went that route, I’m definitely going with a 2x build, and almost certainly the wireless SRAM Red or Force AXS drivetrain with the compact crankset.

I’d like this bike to be comfortable above all, sturdy and reliable, though of course fast is great if I can get that too!

  1. It seems like the only difference between U.P. and U.P.P.E.R. is that the UPPER is lighter. But if I’m on flats, and going long distance, and I’m 50 pounds overweight anyway… do I, should I, care about saving ~180g on the frameset? Might a slightly heavier bike even be a good thing for momentum once I’m up to speed on long rides? Or is lighter always better?

  2. I know very little about wheels so far, but I do know I’d be setting up this bike with 700c wheels, and tires that are not less than 40mm wide, more likely 40-45mm. Which wheels/tires should I be looking at, and why?

  3. Other than frameset, wheels, and tires… what else should I be thinking about right now?

Again, thanks for your input!

I can only speak to the Open UP, as that’s what I went with after my gravel bike search (other considerations were the Ibis Hakka, 3t exploro, the old stigmata). Overall, I really like the bike, I went 1x GRX so a bit different than your setup, so I can’t speak to the AXS 2x, but in general:

  1. I personally didn’t mind the extra 180g for cost savings, would only really think about it if I was racing gravel.
  2. I have two sets of wheels, 700x40 nobby tires for gravel, and 700x30 for road riding. It’s not quite as plug and play as I’d like, does require a slight caliper adjustment. If i did it again, i would have gotten identical hubs and wheelsets to make this a bit more painless.
  3. The bike is awesome on gravel and road, it’s replaced my Canyon Endurace as go-to bike for road riding, I don’t miss the 2x as it’s not my race bike, and I love have a massive bailout gear in the back for super steep climb.

One other thing I’d add is don’t get too hung up on 700cc for your gravel tires, if you go 650b for a wider tire (the max clearance on 700cc is 40mm), you still end up with the same function diameter of wheel + tire ( Gerard Vroomen designed both the Exploro and Open).

Overall, I love the bike, it’s super flexible, you can run basically whatever you need. It’s kind of an N-1 bike for me.


I’ve heard from several people who also ditched their endurance-type road bike after buying an Open UP and now simply have the one bike with two wheelsets, like you. I can’t imagine giving up my Synapse… but I’ve been wrong before! So I’d start with a gravel wheel/tire setup (700x40 or 650x47, perhaps), but knowing that I might add a road wheelset later.

You should pick up some disc rotor shims! They are available for both 6 bolt and centerlock hubs, and will allow you to match up the rotor spacing between your two wheelsets.

I am very close to pulling the trigger on an UP myself! Going to end up doing the same with a gravel wheelset and a road wheelset. Can’t wait!


Cervelo aspero is a very nice ride and might want to add in there. More tire can be taken then the open also.


I recently bought a Cervélo Aspero after looking at the Exploro, U.P., Stigmata, Checkpoint, Diverge, Grail, Topstone, Hakka, etc.

For me, I wanted a bike that would be closer to the endurance road side of front geometry, with a shorter rear end and plenty of tire clearance. I also wanted GRX 2x11 and am not a fan of proprietary parts.

What I didn’t like about the U.P. (Edit: turns out the following applies to the 3T Exploro, not the Open UP) was my research turned up lots of reports of creaking seat and bottom bracket, and frustrating seat post adjustment. Since the seat post shape is proprietary, you can’t fix those issues.

I am really happy with the Aspero. I like big tire clearance, geometry and the ability to set it up with faster or slower handling with the flip chip in the fork. It is stiff, which can be good (efficiency) or bad (comfort). I threw some supple Rene Herse Hurricane Ridge Endurance tires on there and it really smoothed out the ride. I will probably get carbon bars and seatpost too. The other potential downside is lack of rack/fender mounts (I don’t care). This thing flies on the road and does surprisingly well on moderate XC single track. It does so well that I am going to sell my hardtail MTB (and get a full suspension). I may sell my road bike too.

For your area, it sounds like you could ride most of these bikes anywhere, mixing road, gravel and XC.

Aspero is really the only bike you need. I bought mine 3 months ago, and it is amazing.

No, don’t worry about it.

I would also look at the Canyon Grail which you can get with eTap AXS under your budget…

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Do you have any links or places I can read up on these issues with the UP you’re talking about? Would be interested in checking these out before I buy my UP. I think you may be mixing up the Exploro and the Open, because the UP has a normal seatpost and seatpost clamp, so I wonder if the creaking you mention is also regarding the Exploro.

Aspero looks like a pretty sweet bike! Do you actually find yourself switching up the flip chip very often?

Thanks for the tip on the shims! Just ordered some!

On the bottom bracket, I recommend going with one of the Wheels mfg Thread-together bottom brackets, no creaking issues in my experience.

Thanks for the suggestion. I don’t think the Grail CF SLX 8.0 ETAP works for me. If I’m reading things right, that bike is a 1x setup using Force AXS (12-speed) and cannot be ordered as a 2x. I definitely want to stick with a 2x setup, so that one’s out.

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I looked and you are right. I had mixed up the Exploro and U.P. in my notes. I will edit the above post to correct it.

The only real down sides of the UP are the 700x40 tire clearance and the price.


Price is ridiculous. You get the basic Aspero for the same. Guess it’s just like that with (some) bike companies. No wonder Canyon is that successful. :sweat_smile:

For a lot of the carbon gravel bikes the price of just the frame set is almost as much as on a low end complete bike of the same model. It shows how much markup there is on most of the parts you need to build up a bike. Plus I think they do that to help them meet minimum component order numbers.

The Aspero frameset runs $2500, the Apex 1 HRD complete bike is $2800 and that groupset sells for $750 new. I considered Buying the Apex 1 and selling the parts and building the bike exactly like I want. But selling the group as a takeoff, it would probably only get me $500 and the retail markup on the higher end Shimano stuff is pretty high. So I bought the GRX 2x Mechanical complete and essentially get a free wheelset compared to buying all the parts separately, even online.


The Aspero also seems to be available only as a 1x setup (keeping in mind I really want to stick with an SRAM ETAP setup).

The only two options that seem to work well for me (based on what we know so far) are the Cannondale Topstone and an Open U.P. build.

Stock is an issue in many bikes right now due to COVID. I bought mine in early February knowing that the supply of many bikes and parts was going to get tight real soon. has the GRX 800 2x only in 51 and 54cm. Best to check your local Cervélo bike shop and they can see warehouse inventory.

Yes, it is! Thankfully I’m in no hurry… for now I simply continue to get faster on my Synapse. Once I can define very clearly what I want for a gravel bike, I’ll order it and wait patiently. If that means I get my new bike in October, so be it. But at least for now, I can educate myself so I can make better choices.

That’s why right now I’m trying to build my hypothetical Open UP… then I’ll compare that build to a Cannondale Topstone Carbon and any other options we all decide I should consider, and finally pick a bike.

Beware that the Topstone requires a special offset of the rear wheel rim. So you have to custom build aftermarket wheels for it. It also requires use of a proprietary crank. Those things were done to accommodate wide tires, but it still only officially supports 700x40, which honestly isn’t that big. They should have shaped the chainstay better.

By the way, is a great source for bike reviews.

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I get wanting to stick with a etap setup but you can get an etap mini group set and an Aspero for a lot less. I really like mine, few upgrades I’d like to do but not in a real rush since it’s pretty dang nice stock with the GRX 2x setup.

Also why set on the etap love? I found when I had it set up on a bike that it was a touch slow and always had issues going into one gear.

I just got into cycling a year ago. I got a fantastic deal from Mack Cycle on my Synapse with wireless eTap, and I absolutely fell in love with electronic shifting. Constantly having to adjust mechanical shifting, not having the gear shift cleanly into each gear, my drivetrain making noise, all those things have always annoyed me.

I’m trying to get the gravel equivalent of my Synapse… so smooth and comfortable I can ride for hours and it invites me to ride it, and extremely well outfitted so it helps cover for my current weaknesses and helps me get better. But obviously more able to handle a variety of unpaved roads and paths.

Realistically I want something that can handle Grade 1 through 4 gravel. I’m not going to do anything really gnarly… at least not in the next couple of years until I get fitter, stronger, and 50 pounds thinner! :grin:

Does that make sense as an explanation?