johngwheeler

The spectrum from road bike to gravel / adventure bike is getting a bit blurred with bikes like the Cannondale Synapse, Focus Paralane, GT Grade, Trek Domane and even the Specialised Roubaix, all of which can now fit 32mm tires.

I think the sub-category of bikes - more endurance than gravel - are being marketed as "all-road" to some extent.

I'm wondering what the reality is? If you have the opportunity for a significant amount of mixed surface rides, let's say 50/50 paved to graded gravel tracks, would you be more inclined to go the c. 8kg endurance bike with 28-32mm tires, or the slightly heavier gravel bike with wider tires?

I'm not talking riding the DK200 or anything like that; just country roads where the tarmac runs out and is replaced by unpaved dirt, gravel or grass.

Is a nice road bike likely to get too beaten up on this kind of terrain? Thoughts?

motorapido

It's the tires that matter and not the frame. If you can fit 32s that's plenty, even for rough gravel and some mud. I've done thousands of miles of loaded gravel touring on a road frame that fits 32mm tires and have been quite comfortable.

wheelsmcgee

It depends greatly on your expectations for comfort and the type of unpaved roads you ride. I have ridden smooth, hardpack gravel on 28-32mm tires and have been fine.

But around here, the county/townships frequently will dump the rural roads with quarter+ sized irregular gravel, and frankly there is a big difference riding that in 30mm vs say 40-45mm, at least for me. Wider tire is more stable (float over vs cut through) and can be run at lower pressure for increased comfort. I'm riding 45mm right now on my primary bike, and that's certainly wide enough that I don't feel like I have to take detours when I encounter chunky gravel.

So, for me and the gravel I ride on, and not being an elite competitor where shaving pounds could help me win races, I'd have no reason to buy a bike with limited tire clearance when such a wide selection of bikes that will fit 40mm+ tires exist.

JamesB722

I've just started riding the Delaware Canal Towpath which is mostly comprised of small, crushed hardpack gravel (at least on the 20 miles that I've travelled). I'm making the trips on my CF Defy Advanced with 28mm Panaracer Gravel King tires and have not had any comfort issues. On the New Jersey side during my return trip, some sections have larger gravel chunks which are not nearly as comfortable with my 28s but I've passed over them with no problem. If that type of trail comprised the majority of my trip I would need a bike with wider tire clearance since I'm maxed out at 28mm.

Seattle Forrest

I did this on 28 mm tires, on a GT Grade - it was a little rough but plenty doable. I did a lot of unpaved riding on my Grade. I'd say 28 to 32 mm is the sweet spot except for actual gravel (loose crap).

TimothyH

50% gravel and I'm going with the gravel bike every time.

You never know what conditions are going to be like and "doable" does not mean fast or enjoyable.

I hate having to pick my way between rocks on tires too narrow. It is better to have too wide of a tire than too narrow. As long as the tires and wheels are reasonably light then they will give up little on paved sectors.

-Tim-

xraydog

I live in the mountains of north central Pennsylvania. Rides from my house encounter every road surface: Dirt, chipseal, packed gravel, loose gravel / stones and asphalt in varying conditions of repair.

For the last 8 months I have been riding a Specialized Sequoia Elite. It's 42mm tires run with tubeless are about the perfect combination for the road surface and terrain. Before the Sequoia I was riding a Diverge with 32mm tires. It was OK for most surfaces except the loose stones. Additionally the bigger volume tires make the ride much more enjoyable on the less than perfect asphalt.

rm -rf

I think I'd prefer wider tires, with a minimal tread. 32mm, 35mm, or 40mm if the wider ones fit.
For instance, Panaracer gravel kings or Compass tires.

These would be fast on smooth, packed surfaces, and good on pavement. With a wider tire, it would handle the occasional looser gravel or washboards. I wouldn't have to watch the road surface as carefully as I would if the tires were a bit too narrow.

I'm planning to get some tires like these soon.

Marcus_Ti

Heads up re- GKs....they tend to grab and spit out smaller chunks of gravel. Your riding mates will probably not want to draft you no more

IK_biker

In the same boat, South-Central PA.
Have been riding the same type of terrain, plus a bit of singletrack here and there, on a road endurance bike with 38-42 mm tires.
After 51 years of road and MTB riding and wrenching, I still don't know what a "gravel bike" is, what is its purpose, and don't care. What I have in my stable suits me just fine without any gravel-branded machinery.

NoGears

I rode a carbon Cannondale Synapse on 28c Gatorskins a number of times on gravel. No issues really other than the tires cutting into the gravel when it got deep. Now I'm on a bike that has 40c tires and it's so much better...but it's a gravel bike so....but for pavement with some gravel I wouldn't hesitate to take something like the Synapse on 28c tires. I just wouldn't go gravel grinding on a bike like that.

NoGears

Gravel bike is basically an endurance road bike with the ability to run larger tires and usually more relaxed with a longer wheel base for stability and lower bottom bracket. If you are getting 38c+ tires on your road bike...IMO...that's all that matters. I don't really find any difference between how my gravel bike handles and how my Cannondale Synapse handled when I had it. Biggest difference is the Synapse could only take a 28c tire whereas my Renegade will take at least a 40c. My go to "gravel" bike is actually a CX bike with 40c tires.

rm -rf

Ha, that would be like drafting on wet roads, but more painful.

Panaracer has the Gravel King with a file tread, and Gravel King SK with knobbies. I assume you are referring to the knob version?

Kind of confusing, a wide range of tires with the same name.
From Panaracer's web site,
The Gravel King ranges from 23c to 32c.
The Gravel King tubeless is 650b only, 38 to 48. Huh.

The Gravel King SK is 26 to 35.
The Gravel King SK tubeless compatible is 38 to 43, and some new 650b sizes.

And there's a Gravel King Mud version.

Marcus_Ti

Hehe....yea I totally spaced there was a file-tread GK.

TimothyH

Speaking of file tread, I could not be happier with the performance of 35 mm Schwalbe G-One Allaround on pavement.

It is a great road tire.


-Tim-

shelbyfv

My problem with riding on 32s was I couldn't count on the "gravel" being smooth. On the roads here, you never know when there will be ruts from run off in a corner or a large rock sticking up several inches. Not to mention loose rock in creek crossings. I found I had plenty of traction climbing but things went bad going downhill. Just too sketchy for me to maintain any speed and I would get dropped by the 29ers. It seems OP is doing extensive shopping (nothing wrong with that) and I would suggest clearance for fatter tires if riding off pavement is truly anticipated.

Barrettscv 

I agree that it's more about the tire than the bike. I use 700x32 Vittoria Voyager Hyper, 700x30 Schwalbe S One, 700x27 Challenge Parigi-Roubaix and the 700x32 Compass Barlow Pass on firm gravel with excellent results. These tires are ideal for the combination of chip-seal paved and firm gravel surfaces that are common in my area.

I may add a Cannondale Synapse, GT Grade, Trek Domane or the the Specialised Roubaix to my stable to replace my carbon fiber Cyclocross bike in a few years. However, I feel I'm able to ride a mixture of surfaces at a rapid pace by just using a lightweight, fast rolling slick tire.

cellery

I have noticed a significant difference between some of the road endurance and gravel specific bikes is that gravel bikes will sometimes have a beefier fork (in the CF varieties). But yeah I don't see a whole lot of difference otherwise, tire clearance notwithstanding.

blazin

The top 2 in this year's Gravel Race up Spruce Knob rolled on 30s and 28s, respectively. For a race/route like that, primarily hard packed dirt, that makes sense if you are trying to maximize speed, not comfort. The limitations of these tires were evident on the only technical section -- a 2 mile descent on wet, grassy double track -- but obviously not enough to cost them the race.

But, as others have said, for anything that involves protracted chunky gravel or other technical terrain, I'd want 38+.

ph0rk

I've ridden on various stretches of gravel with 32c aw2's, 32c h5's, and 34c exposures. The supple tires (aw2 and exposure) were fine, though like others said, I'd want bigger tires for varied terrain.

I think 45c riddlers will be my next gravel tire for my Fargo, but that bike and those tires are overkill for well manicured trails.

tangerineowl

Put on a new fork so I could fits 32s for the gravel/tracks I was exploring around. On fairly hard-packed stuff it was ok; just had to pick my lines when hitting rougher/stones areas. However as soon as I headed downhill I had to be careful when hitting banked downhills as my front wheel could easily slip out on the small gravel.

mstateglfr 

1- shocked a Synapse now accepts 32s. My wife's 2015 Synapse handles 25s and some 28s...but not all.

2z if i an riding gravel i want a bike which can handle it.
Sure i may be able to ride 25s on it, but is that ideal?...hardly.
32s would be perfect for 2/3 of the gravel i ride. They would be awful and useless for the 1/3 i ride. Thing is, you never know when the loose derp gravel is coming.

Seattle Forrest

Everybody agrees that the most important thing about your frame is what size tires it can fit.

Almost nobody agrees what size tire is needed.

People in the same area seem to go for similar tires, so you might want to see what's popular where you are, among people doing the kind of rides that interest you.

canklecat

I've ridden my '89 Centurion Ironman (racing geometry) with 700x23 tires (Vittoria Zaffiros at 90-100 psi) a coupleafew times on the local MUP's chat trails -- mostly smooth, finely crushed limestone, some sandy patches. Wouldn't be my first choice for unpaved roads, but it was tolerable at 12-14 mph, the pace of our group rides.

A couple of sketchy places would have been a problem if I stopped paying attention for even a moment. After some construction vehicles used the gravel trails during springtime rainy season they sorta scraped the ruts more or less and filled them with powdery sand. Looked good, probably okay for joggers, but that sand grabbed skinny road bike tires and made us plow a bit. Nobody fell but most of us who were riding road bikes were a bit nervous.

My hybridized mountain bike with 700x42 Conti Speed Rides cruises over those gravel/crushed limestone trails like it's a vacation.

Short version: A relaxed geometry drop bar bike with 700x28 or wider tires should be fine for smooth gravel, crushed limestone chat trails, etc.

rm -rf

Wow, lots of good comments in this thread. Keep the tire reports coming!