Is this true - 35mm on a 2020? I just picked up a 2020 Comp and would love to try and put 35's on it. I have the stock 28's but have been hesitant to pull the trigger on 35's. Was going to try 32's and see if there was wiggle room - but, if this is true I may just go carbon tubeless 35's. Tough/expensive call...

Really limiting? I have an older CX bike as my gravel bike - limited to about 34mm. I haven't felt particularly limited by it, including doing full-on mountain bike terrain. Maybe if I was in an area with more mud (I'm in SoCal) I'd feel more limited.

And most actual gravel races aren't that technical. BWR has been won on pure road bikes. Like Jesse Anthony. 25mm tires, I think.

My next gravel bike I'll get with more clearance. But I feel that if you really need tires larger than about 40mm, you need....a mountain bike.

Yes, I have the Schwalbe X-One Allround in 700x35. They're setup for tubeless on the stock rims that came with the bike. I should note that when measured with a caliper, the tires are closer to 33mm wide instead of the 35 they're advertised at. So it probably depends on what tires you buy and what rim you put them on.

Is there any wiggle on that 33?

What do you mean by wiggle? If you're talking clearance I have a few mm on each side. When I get home from work later I can measure the exact clearance between the tire and fork on all sides and get back to you. I'll also measure the closest spot on the rear tire as well.

yeah, sorry, clearance...

Thanks, man. I appreciate you taking a look.

Frame only has clearance for 33mm tires. That's going to be really limiting for gravel applications.


The whole discussion of Gravel and Gravel bikes revolves around, what KIND of gravel do you tide most - let that be your guide.

In my area Gravel riding is 90% Rail Trail with a fine aggregate bed that is smoother and better than some of the paved roads in the area and more traditional gravel/dirt roads that again, for the most part are in a good shape, with well packed down smaller aggregate, and minimal hills. Honestly, a 25mm or 28mm tire with a bit less pressure on a road bike, is perfectly fine.

33mm would be about the most I would ever need or want. But that's just me and the gravel that I tend to ride.

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Steve Fleck @stevefleck | Blog

Your full on mountain bike terrain must be pretty tame if you can handle it with a drop bar bike with 34 mm tires or you should be riding XC and CX world cups

Nah, I didn't say I could do it fast! Just that it's enjoyably ride-able without putting foot down, etc. It's a little like the old days of mountain biking, before suspension and super wide tires. People still did all the things they do now, just slower. That's part of what today's gravel scene is. Mountain biking on the wrong bike. Throwback. It's super fun. I fully support it.

But if we're talking speed for most high-profile gravel races, I really don't see anything where wider-than-CX tires would be helpful. They're helpful for comfort purposes. And comfort can be speed if you're out there a really long time. But at the very pointy end of high profile gravel races, I see narrowish tires. I think 38mm-or-narrower is typical for those seeking maximum speed.

...and, gee: Stetina switched bikes to race Dirty Kanza that same year, because he wanted to run 43s. And they didn't fit on the Madone.

It's almost like there were limits to it's usefulness as a gravel bike...

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Yeah, BWR is like half tarmac (or at least was when I did it).

DK you're just out there for so long that comfort starts to reign, even for pros.

I'm not saying there's not a place for wider tires. Just don't think they're a show-stopping limiter. My personal choice is that my gravel bike is a CX race bike. And if I want something with fatter tires, I'll pull out my hardtail. Other people may prefer something closer to the hardtail as their gravel bike.

My only point here is that you can get *really far* in gravel without the really wide tires. May not be optimal. I'm not going to second-guess Stetina. But you don't *need* that clearance to have a lot of fun and race just about any race, or ride just about any trail. 35mm tires with like 20 PSI can do amazing things. You can do sand pits. You can do mud. You can do 2-foot drops.

Slowman is right that extreme pitches (up or down) benefit from width.

But gravel is many things. And a Roubaix can do most of those things just fine.

Some rides/events, not being able to go wider literally is just that. I've done plenty of rides where no one with tires in the sub-40 range made it through without flatting. Some rides/events, it would just suck (could you do The Oregon Trail with tires that small? Maybe. Would you want to? Hell no.) Some rides/events, it just doesn't matter at all.

That's what a limiter is. It doesn't matter until it matters. At that point, it really matters.

"Gravel" means a lot of things to a lot of people. Some of those things just aren't going to be any damn fun with road bike size tires, if they are even possible at all. It seems to me that would be pretty darn obvious at this point in the game.

*No one* is saying you can't do some gravel riding on a wide clearance road bike. Just that, hey... there are going to be limits to what you can do. Which is, well... true. Seems that it would be pretty non controversial to point this out, but slowtwitch is gonna slowtwitch.

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Tech writer/support on this here site. FIST school instructor and certified bike fitter. Formerly at Diamondback Bikes, LeMond Fitness, FSA, TiCycles, etc.
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I don't think we're really arguing that much.

The poster sounds like a gravel beginner. I think the Roubaix occupies the gravel spectrum. It's a capable gravel bike for a huge amount of what constitutes gravel, and could be all someone ever needs. Most people I know who do gravel seldom do much more than "fire road" gravel. I'm just staking out a place for the road side of gravel.

If someone finds themselves spinning out going up 35% ramps, then, yeah, you need to go to the sub-compact drivetrain and 650b wheels...

Yup.


Maybe?
More than anything, it probably depends where you live. Up here in the PNW, you are going to run out of bike pretty quickly with that bike, especially when it gets wet. Which is, like, now until May. When the rain starts, "Fits 30's" turns into "well, sorta fits 28, but you're going to have to stop and pull the mud out with a stick every 1/2 hour or so..."

Over where Slowman lives in SoCal, you're going to flat all the damn time with that bike, and/or probably break some rims (which is what I did).

Honestly - and here's where I think we really do agree - you can ride one heck of a lot of "gravel" stuff on a road bike. The essential design elements of a classic road bike predate the advent of paved roads, afterall. Something like BWR is, fundamentally, a road bike ride; well within the spectrum of what a traditional road bike can and should be able to do. If this is where one finds themself interested in riding on the "gravel" spectrum, then heck yeah; a road bike is going to be pretty great.

It all just depends, eh?

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Tech writer/support on this here site. FIST school instructor and certified bike fitter. Formerly at Diamondback Bikes, LeMond Fitness, FSA, TiCycles, etc.
Coaching and bike fit - http://source-e.net/ Cyclocross blog - https://crosssports.net/ BJJ instruction - https://ballardbjj.com/

And Carl Decker won Lost and Found a couple of years ago on a rigid XC bike with Thunder Burt 2.25 tires.

Gravel isn't a one-dimensional spectrum.

I'd view myself as being strongly on the road side of gravel. I avoid anything very technical, I almost never ride single-track, and my gravel bike is fit in road posture. I like doing mixed-surface rides with lots of pavement, like Halloween two days ago where I did a century with a 20-mile gravel ride in the middle.
At the same time, the gravel in my area can be quite rough and chunky, so my gravel bike is wearing 2.1" tires and I have little inclination to go smaller. Nearly everyone in my group of friends gravels on >35mm tires, and multiple people have recently switched to 650b in order to fit stuff in the 2" neighborhood.


You can also get your tires cut to pieces. Or you can dent or break your wheels on sharp-edged rocks, which I've seen happen to people several times in the last year.

Width and technicality are only roughly related to one another, as you're exemplifying by talking about "doing drops" on 35s. Width is importantly influenced by surface type; technical trails sometimes have velodrome-smooth firm dirt surfaces, and the plainest of roads can be built out of 2" chunk blasted from the nearest mountainside.

I don't see how it makes sense to give people gravel bike clearance recommendations without knowing how gravel roads are constructed in their area.


If being rumbled by chunky surface all day is making you uncomfortable, it's likely slowing you down even without accounting for fatigue. Being bounced around is waste of energy.

My gravel bike can take 47mm in 650b, which is considered narrow these days with the new bikes from 3T and the Open WI.DE. The gravel in my part of Australia is rough with lots of corrugations. 60mm 650b tyres aren't going to help me when I hit corrugations at speed on a twisty descent. Sure they are better than 47mm, but I think my money would be better spent on a short-travel MTB where I can run fast and wide 29" tyres. Do I wish I had more clearance on the gravel bike for wide 650b tyres--for sure, but given the allocation of bike dollars, I'll get much more use out of a MTB rather than a new gravel bike with greater clearance.

We have a few gravel races here and I usually run my 700c wheelset with fast 38mm tyres. Tried once with 650b and it was hopeless. I also don't love the the way my Open UPPER handles with wide 650b rubber.

Yeah, bad washboarding is a lower-frequency higher-amplitude irregularity than tires are suitable for dealing with. Suspension is the right tool for mitigating that.

For the front, the clearance between the tire and the fork was consistently 4.5 to 5 mm all the way around. In the rear, the closest spot was about 4.5 mm at the closest point on the seat tube. The seat and chain stays had more room. Also, I measured the tires again and they were closer to 34.5 mm, not 33 like I previously stated. Hope that helps! Let me know if you want any more info.

I really appreciate it, my man. Thank you for your effort and responding. All the best to you.

I’ve a Diverge and a Roubaix. The Roubaix is a 2020 with electronic shifting, carbon wheels, and the dial in front “shock”. it s lighter than my Diverge and I have thought of making it my gravel bike by buying a second set of wheels. When I measured the tire clearance on both bikes I get the same width. The largest tire I’ve run on the Diverge was a 34 and that got me across the finish line at DK 2019. Never needed more tire than that so In pretty sure the Roubaix could do double duty. But, I own both bikes and really don’t want to sell my Diverge so I’ll probably continue to keep the Roubaix on pavement.

smccauley49
What kind of tires are those 35’s? I’d like to run 35’s on my Roubaix. Thanks

They are Schwalbe X-One Allrounds, relatively easy install and no issues after almost two years! I believe I originally wanted the G-One Allround but only the X-One was available at the time.