mschwett 

Total fail today exploring some of the well known unpaved trails near me. On some very steep sections (18-20%) which were pretty much covered with small rocks (won’t glorify it by calling it gravel!) I simply could not keep up a speed that allowed enough forward motion to stay upright, was slip sliding all over the place when accelerating or turning, fell a few times, and had to walk the bike a mile or so uphill in my cleats.

Downhill is just as much of a problem over around 10%, even very cautious and gradual braking eventually results in wheel lockup and skidding. Just a total downer to climb 1,000’ and then have to go down at 8mph.

I know my tires aren’t optimum - conti gatorskin hardshell 32 at 60psi… but I’m wondering if the right tires (that are still fun to ride fast on roads) will make THAT much diffference….

zandoval 

I have seen really talented riders tackle tails meant for mountain bikes on a gravel bike with 1.25 tires. Not me, but when I went from my thin road bike tiers to touring 34mm tires I noticed a big change in the way I rode on small loose gravel and sand.

Rolla

32s at 60 psi would not be my choice for steep and loose terrain. I think that wider (and knobbier) rubber and lower pressure would definitely help. Some of the problem might also be mitigated by technique - keeping your weight over the rear wheel as much as possible can help prevent rear spin-outs when climbing, and lockup and skidding when descending. A dropper post might be helpful, especially on the downhill.

SapInMyBlood

Most gravel bikes are 40-50mm . Gatorskin 32's are not designed to be gravel tyres ...

mschwett 

am i going to hate riding something like a 35 or 40mm terra speed on roads? it doesn’t look like the rolling resistance would actually be more than the hard shell tires i’m riding on.

unterhausen

Can you fit larger tires?

It's hard to say if you are going to hate bigger tires on the road, it really depends on what you think you are going to feel. Get all hyped up on Jan Heine's propaganda, and you'll love them. They certainly are much more secure on loose gravel.

mschwett 

700x42 fit; i’m not sure i’d go that big unless it was a second set. i think the compromise for long fast road rides would be too much.

ideal scenario, 700x42 on these wheels with a granny gear on the cassette, get some lighter carbon wheels with some nice soft 700x28s and the original cassette, and be able to switch them easily without having to fiddle around with the chain and derailleur.

Badger6

You might hate them, mschwett , but thats an expectation problem only you can overcome. Gravel tires are not road racing tires. There might be a perceptible increase in rolling resistance on pavement, but let's be honest with ourselves, you are out riding gravel, do you really think there isn't any inherent rolling resistance in the surface itself? Also, all this Sturm und Drang about rolling resistance is absurd...if you are racing on the road on 26s, the few watts you gain or lose could matter. But, on a gravel bike?

The right tires will make a huge difference. I'll echo Rolla , those tires are definitely not suitable for the described surface (and, frankly they are joyless on pavement too). Tread pattern is a consideration...the perfect tires for hard pack or grass are definitely not the perfect tires for mud, but the most important factor to consider is width. 35 is better than 32, and 38-40 would be much better. You can run them at much lower pressures (I run 38s at 32-35psi, and sometimes as low as 28psi....but I'm also running tubeless) to get the best grip for the conditions.

Get the right tires and go have a ball!

mschwett 

thanks. agreed on all counts and it sounds like it’s worth a try. to clarify, I wasn’t concerned about rolling resistance on gravel, but on a typical ride I’d be riding the same tires on 50 miles of roads before or after the 10 miles of gravel, and preferably not changing them out to do my “typical” entirely on-road rides.

the good news is, as you note, my expectations are probably low since everyone hates the ride of the gator hardshells! my main priority was no flats.

tangerineowl

Grades that steep and rocky will always be an issue. Sounds more like a hiking/hike-a-bike stretch
Something I tend to keep an eye out for at times, but that is on a 2.2".

You'd may make it up with a fairly knobby tyre, but there goes your rolling speed on those 50miles.
Solution:- did someone say Jan Heine hype? i.e. knobby 42mm.

Racing Dan

At some point you are better off with a mtb. In the mean time lower the pressure and get some fatter tyres, it you cant fit it in the frame. Very low gearing and low speed is beneficial in technical terrain. You wont be bombing down a stony path on 32s anyway. Consider getting flat pedals if you have a hard time staying upright.

Koyote

Nice wide tires will help immensely on steep and loose climbs and descents, and won't slow you down much on pavement.

Rolla

Normally, I’d say to use the tire that suits the majority of your riding, which sounds like 95% road in your case. While I don’t find wider tires to be much of an impediment on pavement, it seems a shame to run gravel-specific tires for one ten-mile section. Any chance of routing around that section to one that at least avoids the 1000 ft. climb?

chaadster

Be careful of going too wide with the rubber on insufficiently wide rims; as a dyed-in-the-wool roadie (or should that be stained-in-the-chamois!), the feel of a fat, bulbous tire on the pavement is totally unacceptable for sporting work. 35c on 24mm internal width (IW) is great for my tastes in dual (i.e. paved and gravel) use, but 47c on 23mm IW is too sloppy, IMO. Big tires— especially if unsupported by rim width— are just too mushy if you’re addicted to the crispness and precision of traditional road riding.

For the OP, perhaps a tire like the Teravail Washburn 38c would make sense. It has a center slick and shoulder knobs, plus more volume than the currently used Contis, so airing down will help get the knobs on the surface for dirt, and airing up will let the smooth center piece do its thing for nice rolling on pavement. If the OP is doing 50mi on the road to 10mi on the dirt with 1k ft of climbing in that 10 miles, taking a few minutes to adjust tire pressure is time well spent, IMO. Getting up 18-20% grades on rocky surfaces might take some specialzed gear to accomplish, but I’d try a hybrid tread like the Washburn before going full knobby.

mstateglfr 

A 25mm Gatorskin has 19.3 watts of rolling resistance.
A 38mm GravelKing Slick has 20.8 watts of rolling resistance.
A 38mm GravelKing SS has 23 watts of rolling resistance.

So your 32mm Gatorskin almost for sure rolls slower than a 38mm GravelKing Slick.


I love the idea of 2 wheelsets, but would not use 2 wheelsets. If I had only a gravel bike, I would just end up keeping the larger wheelset on the bike for almost all of the time. I know my own laziness.
As for having to walk up 20% inclines with loose rock...yeah thats gonna be tough to ride up no matter what tire you use due to tire slipping at that angle.

Just buy high quality slicks with volume and see if you like em more. Something in 38-43mm thats relatively light, slick, and fast rolling. At worst its a $80-100 bust and you know you need to adjust your routes moving forward to stay on pavement. Or you find out getting off pavement is a lot of fun.

pbass

I'm no expert, but on my 700c gravel bike I have WTB Nano 40's. I really like them. The tread has that very prominent center line, and to my non-roadie self they feel "fine" on pavement, yet they grip great in our CA loose, rocky, terrain as you describe (not as great as my other bike's Sendero 47s, but those are essentially MTB tires). I was kind of surprised, 'cause I had gotten to where I thought even 40c wasn't wide enough!

ksryder

For 50 miles of road and 10 miles of gravel I would probably stick with a road tire but go wide, something like the Challenge Strada Bianchi or the Gravelking slicks that mstateglfr mentioned. Won't be too hard to improve on the gatorskins, which don't have especially good traction on pavement, let alone dirt. My experience with the Challenge tires is that they have not slowed me down on asphalt.

If you look at most gravel tires they have a pretty minimal tread. The slipping and sliding on gravel roads comes from the nature of gravel and dust itself, not the tire, and knobs aren't going to change the fact that gravel moves around underneath you. That said, this does not mean that knobs are completely decorative because if they were, then your gatorskins would be fine, and I definitely don't slide around as much with a gravel tires as I do with a smooth tire.

I've found that tires with a file tread like the Specialized Trigger Pro (rest in peace) roll surprisingly quickly on the road. However, there is a noticeable difference between them and a dedicated road tire, and the few times I've joined a road ride with my gravel tires I definitely had to work a lot harder to keep up.

But like other people have pointed out, those fire roads it sounds like you're on are going to be a challenge no matter what.

scottfsmith

One other thing to consider is to carry a pump and adjust the pressure during the ride. I confess I just run a compromise pressure myself, but if the gravel uphill is long enough it could be worth it to lower the pressures a good amount to make that more manageable.

Pure slicks are often good on gravel but steep gravel ascents are a weak spot, you need some tread for that.

If I was in your situation I would probably run something like Specialized Pathfinder Pro 38s, Conti Terra Speed 35s, or GK SS 35s, and keep at say 50psi for road and 30psi on the gravel ascents.

chas58

Yes, huge difference. But I’ll say that 40mm tire on a gravel bike isn’t ideal for vertical work (Steep climbs, fast rocky descents). I can easily put a 50mm tire on my front fork, and I’ll do that if I’m going to be taking hits any where near 2”.

You are going to get a LOT less rolling resistance on tough terrain with 40mm gravel tires at 35-40psi (tubeless). I get fewer flats tubeless than with gatorskins (and its hard to put a hole in a gatorskin)

That is what I do, but with 32mm GP5000 tires. Way less than ½ the resistance of any Gatorskin – they are seriously fast. I can’t see any real advantage to going below 32mm. I’ve done it – just get more pinch flats / rim strikes.

If I only had one wheelset, for 50road/10gravel, I'd (ideally) use a 35mm slick, and maybe go a little slower for the 10 miles than I would with 40mm gravel tires.

So, a pair of good tires have about 40 watts rolling resistance.

32mm GP5000 is about 15 watts. HUGE difference (especially if I’m riding in a pack where aero is minimized). Doesn't make any real difference on gravel, but its very noticeable on the road.

redlude97

wide 650b slicks may be the answer, I run rene herse 48mms for all road duty, air down for all gravel, air up for mostly road. Keeps the BB lower too

Caliper

YES.

40mm Maxxis Ramblers have served me through any dry climb that my legs can push up and >40mph on some descents (pedaling required, we don't have the hills here to hit that without some hard effort)

blakcloud

Everyone above has you covered on tires but I will argue that it is the wrong bike for riding trails, that is of course we are talking about the Turbo Creo. Racing Dan above said it best in his post.

73 degree head tube angle, 53 mm trail on a medium size bike says to me this is a road/fast gravel road bike not a trail bike. There are better bikes for this type of riding. Bikes with longer top tubes, shorter stems really help in this type of terrain. As nice as the Specialized is (and I mean really nice), I don't think it is the best choice for the 10 miles off road that you are riding. Forgo the trails, find some real gravel roads and you may like it better.

dwmckee

Conti Gtorskin hardshells are really mediocre on road and are completely unsuitable for gravel. Put on either a 38 MM Compass tire or a 38 MM Vittoria Terreno Dry, drop your pressure to 40 PSI or so in gravel and 45 PSI on road and they will be great on gravel and even faster on pavement than the Gatorskins. Those Gatorskins are really tough tires for riding in very flat-prone areas, but are not good for much else.

Badger6

I run the 27mm Paris-Roubaix (the skinnier Strada Bianchi) on my road bike, set up tubeless at 65psi, and they are fast, and work quite well on cobbles as well as the occasional gravel secteur so long as it is not littered with roots and big loose rocks. I have no doubt that the Strada Bianchi perform as well, if not better.

dwmckee

We love the Challenge Strada Bianca tire at our shop but have found that the Gravel King slicks have a harder tread compound and are alarmingly slippery if the pavement gets a bit wet. We no longer sell the Gravel King slicks for that reason but we do love the regular Gravel Kings as a good all purpose tire..