Hi everyone, newbie here. I’m having second thoughts about the Guerciotti Greto I just bought. It fits tires up to 40mm, and I’d like to know from your experience if you think that’s too narrow for dirt trails in the woods or in the mountains, like this (picture) with somewhat coarse gravel.
- Would lowering the tire pressure a bit be enough to avoid flats and ride comfortably, even if not with the same level of comfort?
- What’s a trail that I really can’t do with a 40mm tire? Aside from the typical MTB trails, of course
by atlas_space
48 Comments
Yes
Depends which gravel. It’s a spectrum.
Is that typical of road you ride? If so 40s should be fine. You can use the Rene Herse tire pressure calculator to get a good range to ride.
[https://www.renehersecycles.com/tire-pressure-calculator/](https://www.renehersecycles.com/tire-pressure-calculator/)
I’d ride the road in that picture on 28s. And do often. My gravel bike will take 2.2” but I stick to 40c. If my 40c Raddler tires are the limiting factor, I’d rather have an XC bike.
Somewhat coarse? That’s basically a Strada Bianca
At least there are some off-road focused tires out there.
I think you can counter the missing thickness with a knobbier tire, like the Schwalbe G-One RX or the Vittoria T60 and up. And if Vittoria sells the T90 in 40mm, then they are pretty sure that 40mm will also work in mud.
I’d also go with tubeless, as then you’d be able to go with much lower pressures.
That looks pretty compacted. 40’s would be fine.
I ride on 35’s on all the crushed limestone rail trails by me without issues.
I rode on 28s and 34s, 40mm can handle pretty much anything my dude
It wasn’t very long ago that people were doing gnarly gravel on 38’s for races. MOST gravel that MOST people are willing to ride, you could use a road bike.
The answer is yes. Didn’t even have to watch the video.
Back in the day, I’d use 1.5″ tires for mountain bike racing. 40s are wider than that so you’ll be fine.
yes, i only had 38’s for multiple season and they covered everything i threw at them. Though, I did move up to 42’s because I run into tons and tons of loose sand type of gravel where i live.
For me 40 is perfect.
As others have said, really depends on the kind of gravel you’re riding but generally speaking yes, 40mm is perfectly fine for gravel. I have a pair of 40mm Gravelking SSs on my bike that I’ve really been enjoying. They don’t have the best traction on deeper, chunkier stuff, but the rest of the time they do just fine and feel great on the paved roads I have to ride to get to gravel.
Last Sunday, I ended up doing a downhill stretch with rocks, roots and sand on my Parapera Anemos with 45mm WTB Riddlers, was sure I’d die but the bike and tyres held up supremely – you’ll be grand.
The only places that I would be hesitant with 40mm are very loose sand/rocks and muddy conditions. But those are a nightmare no matter what tires you are using anyways.
Also check if it is the tire width that is your limiting factor or the overall diameter, if its the second, you can always build a nice 650 wheel-set with 650×50.
I used to have a Giant Anyroad, and it was supposed to be limited at 35mm . But was able to fit in 650×49 . Unfortunately that one got stolen and it was a discontinued model so I went with a revolt that can take 700-48 with no issues
Enjoy your new bike!
My bike came with tubed Pathfinders Sport 38s and I rode on much chunkier gravel here in Souther California. Now, don’t ask how my arms and hands felt after descents though.
Moved up to G-One Overland 700x45s
I’d say wider is much better and even if you wouldn’t think so now, having the option of going at least to 45mm if not higher is way better. You can always go smaller, but now you’re at your limit already and 40 really isn’t that large after all. If there’s no turning back then it wouldn’t matter though, just go out and make your own experience and see, you can always chose the road that you feel comfy on with the current setup, whatever that might be 🙂
Nothing wrong with 40’s on that kinda terrain, might get rattled around here and there – but honestly tire size isn’t gonna solve that issue. I only run 38’s on my gravel bike, and ride far gnarlier than that at times. Ultimately if you want the best control and feel on that kind of loose rocky terrain, a mountain bike is the way to go.
If you’re not racing and not riding through rock gardens at speed or something, 40 mm is fine.
to 1.: yes tubeless with lower pressure is the way to go
to 2: Difference between 40 and 45 is mostly comfort. it’s 5mm were talking about. e.g. Sand and beach riding you’d want bigger maybe, but you’d ideally want >45mm for that anyways
Just did a 240 mile gravel ride on 38s. Probably yours are good
Yeah, i became aware of this problem in 2021 after I purchased my first gravel bike with 40mm slick tires and roadish rims ; because I saw people riding gnarly terrain in 35 and 38. I thought that I could do the same ignoring that a lot of people change bikes really fast and it’s not sustainable in the long run to underbike like that (I bikepack). Now I own bike that clears 2.1 MTB tires on MTB rims. Possible solutions are changing to wider rims and tires with more aggressive patterns or if you still have clearance going for some 42s.
I recently went to a race in Belgium called Heathland Gravel. Went there last year on Thunderburt 2.2 inches and this year I came back on 40mm G-One RS Pro.
I lost count how often my rear tire slipped. Sometimes it even happened on a straight gravel road. And I wasn’t even outputting significant power!
Now my bike handling skills are really poor so your mileage may vary. But I’ve concluded that I’m far more comfortable and faster on 50mm and above for the kind of gravel I typically ride during bike events/fun races.
Means I’ll have to buy a second set of wheels and tires for road events but so be it.
Yes. I have always been stuck with my Surly Pacer (for budgetary and practical reasons) which fits max 35mm tires. I have done some of the hardest Midwest gravel rides and while I always wish for more tire, I also always finish the ride. I have never DNF a gravel race or ride. I have done Heck of the North, Ragnarok 105, Le Grand du Nord, the Hollo Gravel Classic, etc etc, on 35mm. And frankly, except for MMRs, B roads and peanut butter, 35-40mm will be the fastest option on gravel.
What might help more than wider tires is a suspension stem. I just added one, and while I don’t feel much difference on roads and hardpack gravel, on the really bumpy stuff, it helps a lot. If your palms are going numb from the vibration, think about getting one.
I ride 40’s but my bike can take 45’s. I mostly ride smooth gravel rail trails (RT). The only non RT places I ride would be Minnewaska State Park Preserve. There is only one area in the park where it is a little sketchy but it’s under a half mile on the west end of Lake Awosting.
The verdict: Send it!
I rode the Canadian winters on 23s, and have taken mtb trails recently on 28s. You’ll be fine if you practice…and have a good seat.
Yeah for sure they are. I’ve taken my 40s on chill single track with roots and rocks a plenty
i ride 40s through everything, sometimes you just have to take more care with choosing your line
I ride 40s in worse.
I promise you that dry gravel for the most part does not need anything bigger than 40. You can do most stuff on 38s if you really want to. People would ride this road on 28s. Wide tires are a fad. Not everything they add is pointless, but it’s almost always overkill. 40s are fine, if not then it’s a skill issue.
I’ve done some pretty fucked rides on 40s just fine. I wouldn’t sweat it.
I like 40mm. I just did D2R2 with them yesterday, and it was a lot of fire road riding. Ive also ridden on MTB trails with that.
I have a pretty high tolerance for underbiking… 🙂
I do rocky mountain paths with 40s (fist to head-sized rocks, MTB territory), it’s slow, it’s technical, but doable.
Its fine, for sure.
Would I choose the option to go wider if possible? Sure? But unless you want to do singletrail, 40 is plenty and should not be a dealbreaker
See you in BCJ
I usually 7.3 inche tires
Super wide, super durable. Huge contact patch and loads of comfort
That looks like category 1 and perhaps 2 at the worst. I ride 32’s on similar terrain and have no issues. I also occasionally ride it on 50’s and the only perceptible benefit is when the trial is wet or very sandy.
My bike also Max’s out at 40s. Yes, they’re great.
Totally enough, the obsession with going ever larger is silly to me- you get more cushioning, that’s a bonus, but you get more weight that makes the bike feel sluggish, the handling loses snap.
Ride the 40’s, enjoy the gravel 🙏
40s are fine, but tire clearence is important imho. The difference between 40 and 45 is massive. I run the Tufo Thundero (48 mm) and it smashes through everything.
😂
I like to go on MTB trails with my gravel bike to make it little bit spicy – and 46 is doable – but I want 50+ – depends on what terrain you wanna conquer 🙂 therefore if you do light gravel even 32s are very fine
I finished a 700km ultra gravel race in the Ardennes on a cyclocross bike with 40mm tires – it wasn’t comfy, but it worked.
at 2) I did MTB-trails with 32mm cyclocross tires, was not easy … then i saw [this](https://youtu.be/_2_nDekAyZY?t=255) (:
I have a “gravel bike” with 35s and a “gravel bike” with 55s. I ride them on the same trails. The 55s are a lot faster and more fun downhill. But you can ride everything on both.
I’ve ridden 38s on chunky gravel. It’s not as easy as bigger tires but fine.