[Closed] Are bigger gravel tyres always better?

Generally, bigger should give you more grip in the dry with the same tyre model, plus give you more comfort from the ability to run lower pressures... At the cost of some speed, which isn't usually much of a priority off tarmac.

At least that's my understanding!

I went from 700x35 CX Comps to 42mm versions of the same, and for past 18 months using Clement X'Plor MSO 700x50 on my gravel bike. Certainly noticed the improvement in comfort, can't say I've noticed any negative on efficiency although I'm probably not that tuned in to notice small differences.

They don't seem to be widely available now though - the Maxxis Rambler 700x50 looks similar but chunkier tread so might be more noticably slower than a skinnier tyre?

I found that once it reached MTB sizes (~50mm) it lost the feeling of zippyness and pretty much just became a poor handling MTB.

I'd like to try it with 650b wheels though so that the diameter was the same.

I found that once it reached MTB sizes (~50mm) it lost the feeling of zippyness and pretty much just became a poor handling MTB.

Hummmm....thats what I wondered. It is an expensive £66 to find that out (though still kind of tempted....). At which point I should probably just ride my pretty efficient HT.

Probably gets down to what % of terrain/surface you are going over on your route and how fast you want to ride it.
I run Clement XPlors (35) and find them a good halfway house for all terrain if you mess about with the pressures.
I have a mixed surface ride planned with a 100 miles of it on the road and 40 of single track. Big volume tyres would be faster and more comfy off road, but I would rather save time on the tarmac sections and take it easy on the other stuff.

I went from 36c to 43c to 50c, all 700's.

I like the 50's and they'll be staying on.

My riding is nearer 75/25 road/offroad and quite a lot of long, fast bumpy downhills.

I think it comes down to your specific set of required compromises, I need my gravel bike to work on and off-road (50/50-ish) and so I'll trade a bit of comfort for some better rolling. I'm also keen to stick to 622mm rims and I would need to go to 650b rims if I wanted significantly more volume.

I've decided to stick to 700x38 for now (I'd maybe go up to a 40), it's more volume and comfort than you get with something skinnier like a 32, but the mud clearance is a benefit over a 42 or bigger and it still rolls adequately on tarmac... (YMMV of course)

I've no doubt a 650b x 50mm (+) would give much more cush but the major trade off would be new wheels which I don't really want TBH, and I can't shake the notion that 650b's on road rolling would be somewhat compromised by the slightly smaller diameter with softer, wider tyres, and I don't really want it to become a Drop-barred MTB, I'm more in the "off-road capable road/touring bike" camp.

Ultimately the biggest benfit I've noticed came from going to tubeless, from there it's just about maximising volume versus any other constraints there might be on tyre width (e.g. frame clearance, weight, rim width, etc)...

I'm STILL trying to figure this out myself.

I've been amazed at the sort of nadgery/loose/rocky terrain I've been able to thread through on my 38mm Terreno Dry tyres on the gravel bike. I put it down to the thinness of the tyre and the quick handling of the bike (it's more old school CX geometry so slightly slacker and shorter than a modern gravel frame).

I stuck the equivalent MTB Terreno on my 29er, 2.1" so 52mm wide. Obviously the extra volume is great fun at speed and bounces over things better, but it also feels clumsier, I'd swear you 'catch' more rocks and loose stuff under the tyre which then spits out or you lose traction on. It's almost the same argument as running skinnier tyres in the mud, they 'cut through' the loose stuff to find traction underneath.

I still reckon that for slower, skinnier rocky singletrack the narrower tyre might be the better choice, would like to compare my times through the Gaick Pass or Glen Tilt on 38mm tyres vs. wider tyres...

Sorting out bikepacking step up at the moment, and wondering if going 50 mm front and rear would be better (the Niner will take this) for more give, or are they just going to be super inefficient?

Higher volumes and lower pressures carry a load more efficiently. It counts for an unloaded bike too but that 5-10kg you strap to your bike can't be moved or unweighted as easily as your bodyweight.

I've settled on 650 x 50 for road and gravel stuff, loaded or not (generally 2/3 on road, 1/3 off road on byways and southern singletracks) but it's all subjective stuff.

I've got GravelKing SK 35s on at the moment and they definitely seem capable enough off road while still letting me get there without feeling like I'm riding through treacle. When they give up I'll definitely try something bigger though as I only put these on originally because I thought I'd fit also mudguards for commuting. Hah.

Been impressed with Pirelli 45 mm 700c tyres
Can’t see a downside - they are v quick on the road.
Did a section of the Pennine BW yesterday- which was horrible and rocky. Would not have wanted a smaller vol tyre

I was faster on 33mm knobbly tyres on the SDW than on 42mm semi slick wtb. However that’s a 100 mile ride, it was much more comfortable on the wider tyres.
Saying that I don’t think the 33mm tyres made much difference speed wise. When doing the ride on the 42mm tyres it was baking hot, I had to stop and find water (and ice cream) whenever I could. Definitely had more breaks because of the heat.
(But I was faster and more comfortable on a very light 100mm travel 29er with 2.1mm tyres)

I found that once it reached MTB sizes (~50mm) it lost the feeling of zippyness and pretty much just became a poor handling MTB.

Agree, but for me that is at an even smaller size. I tried 25, 32, 38 and 43 on the same bike a few years ago and the 43 just felt MTBish.
I am back using 25c now (I know that is not going to be a popular option for gravel for pretty much anyone) but I just like the way they feel.

There is a lot of hokum on this.

A wider tyre gives more grip at the expense of weight and aerodynamics. Whether or not handling is impacted depends upon the wheel/tyre/bike interface.

It does not really give much lower rolling resistance if measured at the same levels of 'tyre drop' - i.e. tyre sag. Don't believe me? Look it up. All of the "wider tyres = lower pressure = less resistance" stuff is comparing it at the same pressure. A wider tyre at the same pressure is a firmer spring. Of course there will be lower RR.

https://www.bicyclerollingresistance.com/specials/grand-prix-5000-comparison#drop45

GP5000 @ same comfort level. 23c: 11.3W, 32C: 11.4W (plus a load of aerodynamic drag and energy loss due to mass)/

Anyone know what options are available for 700x50 in tan wall flavour... quite hard to find!

Vittoria Terreno XC TLR 2.1" measures up 52mm, rolls fast. Has narrowed the gap between my 29er and gravel bike quite considerably...

Anyone know what options are available for 700×50 in tan wall flavour… quite hard to find!

Merlin have the GK in 50 x 700 tan wall.

Hooja- I run wtb venture 700x50 tanwall. In stock in tweeks As just bought some more few days ago.

I tried running 650b x 50mm tyres and went out for a ride with my roadie mate.

It was awful. I really thought, how bad could it be. Turns out pretty bad.

Sold the 650b wheelset and kept some 32mm tyres on the gravel bike which I now happily ride with said roadie mate. And when he’s looking a bit smug I make him do a little bit of farm track as an ‘essential loop closer’ just to rattle him about

Thanks all. Some interesting thoughts, opinion and some science. I like the 43 mm tyres I’ve got - seem a good balance of comfort and zippiness. Might stick with them and see how it goes fully loaded before faffing around with another variable.

I've those 700x50c Gravel Kings, on 25mm internal rims running tubeless at 28-30psi.

We've next to no mud though here on the stuff we ride, hard/rough surfaces.

There is a lot of hokum on this.

Well yes, but that research is for a smooth surface. Are there and test machines that do varying degrees of knobbliness?

I'm on 50x650 at the moment but plan to go back to 700c with narrower tyres. I find for the rides I tend to do the wider tyres take more out on the roads than they give off road. I'll keep the 650's for more off road focused stuff but I reckon 38/700 is the sweet spot for me.

More horses for courses stuff. I ride short rides (no more than 2 hours) and don't care about comfort because of that so ride a bike I like the feel of (which for me is narrower tyres)
If I was doing loaded touring (riding all days, heavier bike etc,.) then no way would I ride what I ride now as the sprightly feel of the bike is a lot less important that comfort and stability.

700x50 Goodyear Connector here on my Sonder Camino.

For what its worth, I also own a reasonably light XC style hardtail and run 2.2 tyres on that.

There is still a vast difference between the two, so I dont agree at all that 50mm tyres on a gravel bike is almost a mountain bike and thus pointless.

Part of the issue is that 'Gravel bike' as is about as all-encompassing as 'mountain bike' these days - Some of what I see marketed as 'gravel bike' is just 'slightly less flimsy road bike' to me.

See also 650b wheels which are (unpopular opinion coming up) just an excuse by manufacturers to sell gravel bikes with poor tyre clearance on the larger wheels.

Posted this before and probably a bit dated now maybe should go to 50mm...from cyclingtips

https://flic.kr/p/2kGyDqM

From what I see 40mm is now being sold as the bottom end of gravel tyre width...and suspect this is partially because people are pushing what are doing on gravel bikes and what is being ridden is pretty rough...personally I'm happy with the comfort of tubeless at 32-35mm on the washboard/corrugated roads we have in these parts (Victoria Aus') but do have a CGR seatpost and Redshift stem ...liken it bit to "I need a dropper" usually a short section of steep rocky better ridden on a hard tail? Or sucked up if wany to ride mixed ...looking last week for new gravel tyres in 32-35mm area and shortages are less of problem here just that road now goes to 35mm..got some heavily discounted 33mm gravel kings...presumably because will be discontinued

Edit washboard/corrugated gravel roads

44mm Maxxis Raddlers on my Faran and so far pretty impressed. I was a little worried they would feel rubbish on the road but so far so good.
Admittedly the bike they replaced was running Marathon Plus touring boat anchors which are quite possibly the deadest tire ever...

@ibnchris I tried running 650b x 50mm tyres and went out for a ride with my roadie mate.
It was awful. I really thought, how bad could it be. Turns out pretty bad.

I thought that until I tried some supple 650x48s (Rene Herse) - compared to WTB Byways they're much faster on the road and more capable off it.

Fat tyres aren't all the same.

See also 650b wheels which are (unpopular opinion coming up) just an excuse by manufacturers to sell gravel bikes with poor tyre clearance on the larger wheels.

Maybe not 'excuse' but there's some truth in that. It's also about 650s fitting a 50mm tyre into a more road-like geometry. That combination of near road bike agility with 50mm tyres is ideal for some of us, esp those wanting to use guards as well. Some of us would prefer a 700 x 50-55mm tyre but that starts to dictate longer wheelbases and other geometry considerations.
Wheel OD and tyre volume both good variables to adjust independently for the way they affect handling and how they deal with bumps.