Tire Selection for the Continental Divide Trail

[irwin7638]

I'm several months away from this, but am considering riding from Whitefish to Denver, largely on the CDT.  I've noticed from most of the photos and blogs I have looked at that people are riding 2" knobbies of one brand or another.  Most of the trails and roads seem to be packed gravel rather than loose technical terrain.  How do any veterans feel about something like 2" Schwalbe Marathons with a little less rolling resistance?  Are knobbies definitely necessary, or just a good thing in some limited areas?

Marc

[newfydog]

I think a  racing type tire with low profile knobs would be fine, but most of those have sort of scary thin sidewalls for loaded touring.  There are some sections with sharp rocks.

I've found the Geax Saguaro can't be beat.  The center knobs sort of link up to form a center ridge, particularly after some wear.  They roll great on pavement pumped hard and handle like a knobby mtb tire when run softer, and are really tough.

[irwin7638]

Thanks.  The  Marathon's don't have the knobs you are talking about but have really tough sidewalls. If I can find a cross tire with beefed up sidewalls it would be great, but most that I have seen are narrower (35-39mm) and, like you said are too flimsy for loaded touring.

Marc

[newfydog]

I did a bit more thinking about your question, and looked at the Schwalbe marathon.

I would look for a smooth rolling tire, but not a narrow one.  On any unpaved route, wider tires roll best.  Check out this;

http://www.schwalbetires.com/wider_faster_page

We have used the WTB Vulpine and The Kenda small block 8 as a front tire with good results.  I hesitate to run them in the back with a load.

It is true much of the great divide is cruising on gravel, but there is a lot of washboard, so you'll like a soft fat tire.  You also will appreciate more knobs than the Marathon on this charming piece outside of Helena:

[irwin7638]

That's what I am wondering about.  The Schwalbe Marathon Dureme is made in a 50 cm version, the tread is still conservative but from what I am seeing, a wide tread is going to be more important than a knobbie.  That patch in your photo looks tricky, but a knobby wouldn't really be useful unless it was muddy.  It seems, from what I have seen, that a large footprint will be productive, but knobbies counterproductive over most of the ride, does that make sense?


Marc

[Pat Lamb]

The Schwalbe Marathon Dureme is made in a 50 cm version, the tread is still conservative but from what I am seeing, a wide tread is going to be more important than a knobbie.  That patch in your photo looks tricky, but a knobby wouldn't really be useful unless it was muddy. 

50 cm is getting close to a tracked vehicle, it should go over just about anything if you can pedal it.  Are you perhaps off by a factor of 10? 

[irwin7638]

ROTFL!   Yeah I'd have to be pedaling a truck.  They have a 50mm Dureme which is about as bulletproof as tires get, but don't have knob tread.

Marc

[newfydog]

I find knobs are only slower at high speeds on pavement, where they buzz.  On gravel, rolling resistance is more related to casing flexibility.  There are all sorts of test with some pretty knobby tires rolling great.  I do find them more stable descending any sort of loose gravel road. And having ridden that gnarly section in Montana in dry conditions just last week, essential if you want to try and ride it.

On the other hand, those tires which feature a big slab of rubber with a modest thread cut in, such as the Schwalbe Marathons will wear forever but ride like a dead fish.  I have a 26 x1.75 Marathon and find it amazingly heavy and slow.

Here's a good thread from bikepacker.net on what tires people use for the Great Divide.  The WTB nanaraptor and the Geax Saguaro seem popular.

 http://www.bikepacking.net/forum/index.php/topic,1924.100.html

Here's some test data.  The Geax looks good, and the Continental X king looks phenominal.

[Old Guy New Hobby]

Newfydog - very interesting. What is the source for the test data?

[sspeed]

Are you going to be tubeless?  I just rode the Monarch Crest trail (which is on the Continental Divide trail for *I think* half of the ride, I could be wrong about that) from Monarch Pass to Poncha Springs in August.  I pinch flatted 4 times in 30 miles.  There are a lot of sharp rocks in sections of the trail, some of it is rather loose and sketchy as well.  If I did it again I'd probably be tubeless with a set of 2.35 Ignitors.

A friend did the entire Divide trail with a tubeless 2.25 Knobby Nic up front and tubeless 2.25 Racing Ralph in the rear.

[irwin7638]

I hadn't even considered tubeless until you mentioned it.  What's the advantage?

Marc

[sspeed]

Took me years to be convinced, but no pinch flats, which is huge on a rocky trail.  You can also run much lower pressures, which translates to better handling and less rolling resistance.  I haven't figured out the physics of the latter yet, but the difference is dramatic.

[newfydog]

Tubeless is great, but there is a bit of a learning curve.  We now go tubeless, and carry a slime tube in the event of valve stem failure.  Why a slime tube?  One a tire has been run tubeless it can be full of things that would prick a tube.  Thorns and wires cn be in there for months without causing any trouble.


The tire data link is somewhere in that bikepacker thread.

[sspeed]

Definitely a small learning curve, especially if you use non-UST tires and go tubeless as they won't set the bead as well and will have pinhole leaks that need to seal. 

I used UST Maxxis Ignitors and didn't even need to use sealant to get them to seal up.  That may be a better option for a long tour like this.  Plus UST tires have stiffer sidewalls, which may be better suited for touring.  The downside is they weigh more, but you don't feel it in rolling resistance.  When I switched to tubeless my bike rolled faster than it ever had.  I had gobs of Strava activity on the same segments to subjectively prove that to myself.

I can't imagine riding tubes on the mountain bike again...  I'd recommend them in a heartbeat to someone doing the tour you suggest.

[newfydog]

What rims are you running sspeed?  Most of our wheels and tires are non ust and the is no way to get the initial seal without a compressor.  We used a conti ust tire in the desert last year which might seal up with a hand pump but I have not tried it.  The learning curve applies to both riders and manufacturers, but I have no doubt tubeless is the future.  They roll better and I have not had a puncture for two years.  I have had two burpouts which sealed and just lost some air and one valve stem seal breakdown..  I think as my stuff wears out it will.get replaced with better and better tubeless set ups.