king_boru

Try an APP called Trailforks. Or use their website. It has a decent portfolio of trails that will be in your area, if of course anyone has listed them.

noglider 

I'm not all that experienced at off-road riding, but I don't see how knobs on your tires help with rocks and roots. Knobs are for grabbing in slippery stuff like sand and mud and snow. My gravel roads -- the "carriage roads" in Lake Minnewaska State Park Preserve in NY State -- have pebbles up to about golf-ball size, for whatever that's worth. If my tire goes over a pebble, either the pebble jumps out from under me (not common) or my tire goes over it.

Why don't you try it before deciding what you need? Equipment matters less than skill, and you acquire skill with time.

johngwheeler

Good points. It's probably more the increase in tire width that interests me, more than the tread per se. On the road, I need the 32mm Bontragers to be 60-65psi to roll well. That makes for a bumpy ride off-road! I guess I could lower this on gravel somewhat, but what from what I've read, I would probably get more suspension from a wider tire.

As an example, I have a pebble driveway at home. On the 32mm tires I can only go a few metres before the bike slips or slows down too much. Even with 35mm tires (on a different bike), I can ride over the pebbles successfully.

noglider 

Yes you will like wide tires and low pressure.

Craptacular8

I don't find the Challege Gravel Grinder Race tiers (700 x 38) to have any drag on pavement...on the road, only the file tread is coming in contact, not the side knobs. That said, There's not a lot of reason to run anything with tread unless you are racing cyclocross, so as I wear/replace, I'm going to be putting on Compass Bon Jon Pass tires (700 x 35) https://www.compasscycle.com/product...ts/tires/700c/ Jan has a blog where he discusses his theory on gravel, err tire treads here: https://janheine.wordpress.com/2017/...-gravel-tires/

I've ridden plenty of gravel on slicks to chunky knobbies, and it's the lower tire pressure, supple tire wider tread that seems to make the most difference to me.

noglider 

I find Jan's reasoning to be entirely convincing. I hope to be able to try tires like that on gravel, but in the meantime, I'm riding tires that are very similar but just a bit narrower. Not only do I have the Pasela tires, I have some Grand Bois tires, also made by Panaracer. They're lighter than the Paselas. They've been nice on smooth roads, rough roads, and gravel.

With those light tires, there is a chance of a sidewall cut, but it's small. If you think you're taking a risk of being unable to pedal home, carrying a spare tire isn't a burden, since they're light and easy to pack. But I don't carry one.

350htrr

Bah, humbug... Here is my scientific test... For about 8 years I have been going down this hill on the same bike the same size/type of tires (2" mountain bike tires), and 52KM/Hr was the fastest I ever did it, I tried to better that speed for hundreds of rides down that hill... NOPE, Then one day after I came home from a tour I had narrower tires on that I put on for the tour I just finished and (1.5" road tires) and WOW, I went down the hill at 54KM/Hr, I was shocked that it made that much difference so the next day I did it again, this time going for gold, and... 56KM/Hr.

So Yea, a gravel tire will slow you down some, I am still going to go with the old ways of thinking.

RubeRad

What's the tread difference between the 2" mtb tires and the 1.5" road tires?

What'st the pressure difference as well?

I'd be very very interested to see data gathered by you for successive no-pedaling roll-down tests with tire pressure dropped at, say, 2psi increments (decrements)

350htrr

2" mountain bike tire 40PSi, 1.5" road tire 80PSi... Probably not going for further tests, seems pretty conclusive to me.

RubeRad

Yeah, the difference you're seeing is from knobby tread vs smooth tread. I'm surprised you only gained 2kmh. Now what you want to do is decrease your road tire 2psi at a time and watch your speed increase as you enable the tire to isolate more and more vibration from the frame and your body.

johngwheeler

Those tires (pictured) seem very different to me! I'd also be interested in seeing data for these experiments:

1) Same tire width with different tread profiles

2) Same tire width at different pressures

3) Different tire widths with same tread & pressure.

I know there's been a fair bit on research on (3), with a tendency for relatively wider tires at lower pressure (e.g. 28mm) even for pro racing.

What do people think of tire treads that have a smoother central strip with more knobs on the outside?

John

350htrr

4 KM/Hr is what I gained 7.69% actually. A huge number in my book... and, the question is will a gravel tire slow me down? I took it to mean from as compared to a road tire...

RubeRad

It's a solid design. Almost all of riding (especially road riding) is straight ahead, so a tire with a smooth center strip can be relatively efficient on the road, yet side-knobs can give turning traction on softer terrain.

canklecat

They're great except on pavement. On tight fast turns those side knobbies, or any pronounced tread, can feel a bit squirmy on tight turns.

Both my bikes have tires with pronounced tread on the shoulders: Continental Speed Rides with knobbies; Michelin Protek Cross Max, deep chevron pattern tread. Both took a little getting used to, coming from tires with shallower shoulder tread.

It's not a huge adjustment, just be cautious at first and practice a few turns on pavement away from traffic -- a large parking lot, rural area, anywhere you don't need to worry about other vehicles while you're getting the feel of new tires.

The plus side is the traction in dry grass, stuff like climbing around levees or hilly open fields, pastures, prairie, etc. The side knobbies and tread seem to help more in those situations than on most gravel.

If you prefer more predictable behavior in all conditions consider something like Schwalbe Big Ones or G-Ones, which have a shallow file tread all across the tire, including the shoulders. Ditto, Maxxis Hookworms (26" only, IIRC), Michelin Protek Urban, and many similar tires.

Darth Lefty 

I'm not a fan. Turning on dirt is important but so is braking and climbing. If you need tread at all, you need all tread. IMO.

gregf83 

You might see a small difference but it's not enough to worry about. I normally use 28mm GP4000s on my winter bike but recently tried a set of 40mm Schwalbe G-Ones on some gravel rides. I left them on for commuting and did a few excursions onto trails on the way home. My normal commute time is around an hour and it seems about the same, perhaps a couple minutes slower, with the G-ones. I commute on mostly smooth roads but still like the fat tires. I think I'll leave them on and see how long they last.

mstateglfr 

I just finished a 25mi pavement ride on 40mm clement xplor mso tires. They are the 120 tpi.
My time was within 2 minutes of what i did on thirsday with one of my road bikes.

I wasnt pusbing to set some record, just consistent riding. I feel no slower and dont find i exert more energy.