[Closed] *Gravel/Adventure tyre size ... What is the sweet spot?

if it starts looking like a drop bar 29er then you've probably bought the wrong bike.

No, I'm happy with the bike, and purposely didn't want a 29er HT. But you're right, I don't want it to be a drop bar 29er/650b MTB either ... Just trying to figure out the sweet spot for wheel/tyre size that allows it to be capable-enough off road whilst brisk-enough on the tarmac bits.

IMO there is no sweetspot, just a choice of which to compromise.
I like reasonably gnarly treaded 35C and compromise on comfort. I don't weigh much so I run them at 40-45psi. It still feels fast on the road, which I like.

Your mileage will definitely vary.

Edit: I found that going fatter actually lost the advantages off-road, in that it stopped cutting through to find grip. If it's really rocky, I just tend to slow down.

Go as wide as the clearance will allow to enhance reasonably dry off-road riding, knowing that the wider you go, the more aero drag you will be fighting above ~15+mph on the road.

I'd expect the sweet spot to be something around 33mm to give decent all-conditions performance.

I guess it depends on the ride, I only ride roads to get off roads so I’m happy to compromise rolling resistance for grip. For instance, ritchey megabite 700x38c are fantastic for my boggy Welsh hill rides and here in Cotswold filth, but I wouldn’t do lots of tarmac. However I have 2.1 on the 650 set and the single track is definitely more fun, but clearances on the fork are a bit spindly, so generally ride these in the summer.
I’ve had 35, 40, 42, 47 tyres in all sorts of guises and of course proper cx tyres in varying patterns. True gravel it’s possible to get away with very minimal tred, but volume helps.
In short I’m keen to get away with as much volume as possible!

I'm running Specialised Sawtooth 42's on my Kona Rove ST.

They worked well on singletrack photographing an enduro last week and tonight I was trying to hang with the roadies. Trying to, it wasn't the bike letting the side down.

32 Roubaixs were faster on the road & surprisingly capable off road.

41 Surly Knards are fantastic in the mud but suck on road.

I've had a pickenflick for a few years now and run it several ways. I thought the ride improved dramatically when I went to 650b x 47. I think this is because 700c wheels with big tyres start to get a bit heavy/unwieldy above 33ish. my winter single speed niner rlt runs 650b x 38 GRavel kings which are great as quite abit lighter.
Mine is a 53cm small frame so this may be why the small diameter wheels work better?

" I’m keen to get away with as much volume as possible! "

in that case it's a question of pressure, if you have a long road stretch to get to the mud, start with high pressure and let a bit out when you are about to go off road and if there is a long road return then pump a bit back in if you want to

In an unscientific way I would say 700 x 38c or 650 x 42c.

in my experience that gives you the best compromise between weight, rolling resistance, choice and retains the ability to lower pressures for enhanced grip and comfort with risking pinch flats or rim strikes

I fitted a set of 38mm (actually 40mm)  Vittoria Adventure Trail II TNT tyres to my cross bike for this kind of thing, non-racing, commuting and messing about.

They're fine on the road - can average 27-28kph on my 52km commute, good on man made trails and single track at trail centres and aren't bad when it's a bit muddy, they are however total pants in deep mud, but that's not what this bike is for - until CX season re-starts and proper 33mm CX tyres will be fitted

My experience of riding lots of gravel roads is 2" to 2.35". The larger volume lets you air down so you get plenty grip from the tyre conforming to the surface.

Compared to riding on 40mm tyres it's a lot more comfortable and also you don't have to worry much about the surfaces or the odd rock pinging you off into the undergrowth.

So far it's all been on Schwalbe Big Apples which roll really well. Their slick tread works well enough on everything but slimy surfaces, and then it's a matter of adjusting pace to the surfaces.

Like Tang up there ^ I don't consider myself a roadie. Roads just exist to let me get to offroad.

I'll always take the dirt alternative if there's a choice.

However I have done several century + road rides on the 2.35" tyres and it's no slower than when I have done it on narrower tyres. When I do a long ride it's Audax pace, not race.

I predict that gravel bikes will evolve into bigger tyres within 2-3 years. If that means they end up looking like a dropbar 29er, that's no problem. (Although I'd prefer a horizontal toptube).

I haven't tried this yet, but I'm surprised more people aren't running bigger tyres upfront on gravel bikes.

Half fat, or half plus MTBs aren't uncommon, so a gravel bike with a 30/35 out back and 40/45 up front makes sense to me. Think I'm going to use my girlfriends Genesis as a guinea pig.

so a gravel bike with a 30/35 out back and 40/45 up front makes sense to me. Think I’m going to use my girlfriends Genesis as a guinea pig.

I'm running a 43 mm GravelKing SK up front and a 35 mm of the same out back on my Genesis. Works really well IMO.

I'm planning on doing the same, mostly because of frame clearances, although I think a 42c might fit in the rear I'll just get one and see, if not I'll stick with the existing 38.

TBH on a rigid bike or a hardtail the advantage of a big tyre up front are largely negated by the fact the rear can't keep up anymore. Most 'half fat' builds are simply because a fat tyre fits in most rigid forks, but in very few 29er frames.

Great, that's pretty much what I was going to do with hers 🙂

Hmm, that's not how I feel about the half-plus on a rigid, as I always feel like it's only the front end that's slowing me down and the fatter tyre helps. And keeping a skinnier one on the bag keeps the thing quite nippy.

Think I'd agree with you for a hardtail though.

Sporadically, I put the Wazoo in "Frankenbike" mode, with 26x4" JJ at the rear with 29x2.35" G-One/Speedster at the front, it's surprisingly fun and nippy... Must be the aero factor of the thinner front wheel. 😉

Having used 35mm Clement Xplor USH, 40mm WTB Nanos and 40 Schwalbe G-Ones, I would say that I'm happier on the 40s than the 35s on anything vaguely rough.

The G-ones are pretty bloody quick too for  their size.

I've currently got WTB 37C Riddlers on one bike, I think I'd be pushing it to get the 45C version in there but might try the 40C Nanos at some point. Even though they are more off-road oriented than the Nanos they roll surprisingly well on road and at this time of year they handle pot holes surprisingly well. I've set them up tubeless - one was easy, one was a 'mare. Not done enough distance yet to be able to determine how quickly they wear.

If you did want to go the "road plus" route then the WTB Byways seem to get good reviews but at the moment there aren't that many competitors.

I like the 2.1 nanos for most monster-crossing, and they dont slow me too much on the roads.  Narrower flavours I expect would be similar bit it's the extra volume that gives the cushioning I prefer on a rigid bike if offroad for any good time.

On back-roads (mostly tarmac and towpath)  I've decided to switch to Schwalbe Silento 35c hoping for better protection and clearance for full mudguards.  They weight the same as the Nano 2.1s   Initial tests have been positive and the Silento rolls smoother and a little quicker than the Nanos, but not by much (if I inflate the Nanos to max) But out of the two I'd have the Nanos all of the time with the proviso that I'd expect more punctures. Running them tubeless could be the solution to the this.  First choice for me is more about the type of riding I tend to do in summer (long bombholed farm tracks with a little woodland).  It's no great hardship for me to change to 35c's in anticipation of a lengthy tarmac-only tour .  Have also had multi-surface success with big-volume Big Apples over three seasons, but they are heavy no escaping it.

Anyone know the biggest size tyre that’ll fit on 27.5’s on a Pickenflick?

If you put 26" wheels in there, what width tyre could you fit in?

For 700c my personal opinion is 35-40c is optimal for road/gravel/off-road.

I’m running 650b x 47 byways on my new Salsa Vaya, haven’t had a run out but expect them to be both fast and grippybased on reviews will see after the weekend when out for first ride

Got 38 on the back and 40 on the front. It's capable but not comfortable off road and comfortable but not capable on road.

But then I'm not racing and some days only the cross bike will do!

I’ve got 40c’s front and rear on the Pickenflick but could be tempted to go 27.5 if something bigger will fit

Go big and don't go home.

Tang & Epicyclo ... Like you, I have traditionally seen tarmac as a necessary evil to get to and between the trails. But the advantage of this type of bike is, of course, to mix it up, cover greater distances (and get to further away trails!). I've run my Hack (which until now, has been my only drop-bar bike), used for commuting, local trails, 3PCX, Dirty Reiver with mildly knobblie tyres in the 35-40c range ... Landcruisers, Conti Cyclo X-Kings, Nano. That's been a pretty good compromise to cover all those bases, but now I have the Pickenflick, think I want to run it with tyres a bit more capable and comfortable off road.

Think I'll stick with the Conti AT ride 42 for now, and when they run out, see if I can squeeze the 45c Riddler's in.

Think 650b is still an option for when funds allow ... As a couple of people have noted, should be able to run wider rubber whilst remaining fairly nimble & light.

I currently run wtb byways which are 47mm and I've previously used maxxis refuse which are 50mm. That's about as big as you could go at the rear - more room on the front fork

all 650b

Ok, so for my intended useage, I'd assumed I would err on a fastish rolling knobbly tyre given that mud and wet trails are not uncommon in the UK ... So how do the 'road-plus' tyres (ie a slick/nearly slick central section, with a bit of tread around the shoulders, eg the WTB Byway/Horizon) fare on typical British trails? I'm sure on hardpack, dry, or well-drained gravel, they're fine, but mulch, mud, wet woodland singletrack?

What about a wider, knobblier front and a slick/nearly slick rear? (Eg Riddler/Byway ... If they did them in the same wheel size?) Anyone tried this approach and what tyres did you settle on?

hardtailonly

...I’m sure on hardpack, dry, or well-drained gravel, they’re fine, but mulch, mud, wet woodland singletrack?...

If you're going to be riding predominantly on that then you need knobs on your tyres.

However I use the slick treads because they handle most conditions and just ride more carefully on slippery stuff.

I have found that a slick 2.35" tyre at low pressure will handle a lot more varied conditions than a higher pressure 40mm tyre - on those you need knobs for more on the dirt.

"I’ve currently got WTB 37C Riddlers on one bike, I think I’d be pushing it to get the 45C version in there but might try the 40C Nanos at some point. "

40c nano measured exactly the same as the 45c riddler on my dt460 rims. Riddler was a little taller though.

Now have riddler front, GK 43c rear, which I prefer to the Nano.

If you want to ride in muddy slop, you perhaps ought to be looking at X-One Bites.

I've got a 2015 Charge Plug 3 and at the moment I'm 650 curious.

I've just fitted a set of Vittoria AdventureTrail II's as they were massively cheap at Planet X, set them up tubeless but I've not been out on them yet, planning tonight.

[url= https://farm5.staticflickr.com/4668/40191644771_96e5838c98_k.jp g" target="_blank">https://farm5.staticflickr.com/4668/40191644771_96e5838c98_k.jp g"/> [/img][/url][url= https://flic.kr/p/24eAFJB ]Doing a tubeless[/url] by [url= https://www.flickr.com/photos/70930025@N02/ ]davedorson[/url], on Flickr

For a good while it was my only bike, and I really enjoyed bridleways and cheeky trails, but around October last year I figured I was probably on the wrong bike, as I was finding the really thick sticky clag to be a chore.

I tried a few set of tyres, I'd settled on some OnOne Gravel tyres in 700cx33, they were a bit cross esque and pretty supple, they were fine on hard packed stuff and could take the odd jaunt off the beaten path, but properly off road they weren't much cop.  Never set them up tubeless, but they were quick on road, fair in light off road, but a bit crashy if you ran a pressure that'd prevent the odd rock pinging you about or dinking your rims.

I'll let you know how I get on with the Vittoria's, (38mm) but I really like the idea of more volume after riding my 27.5+ Kona Unit.  I'll be honest, I was pretty ignorant to the fact they were even a thing on gravel bikes.

I've got the very same Vittoria Adventure II TNT tyres on my Canic CXC, they're very good indeed.

I can happily truck along at 30kph on tarmac and they handle bridleways and hardpack really well so long as you remember what you're riding!