Coated in Rubber

Coated in Rubber

I’ve been experimenting with rubber lately. No, I don’t mean anything that would get used in “50 Shades of Gray,” though. S&M isn’t quite my thing, unless you count what we do to ourselves in the saddle, and in that case, well then maybe.

Taking road bikes on both paved and unpaved surfaces—and I’m being careful not to say gravel because I have encountered gravel twice in the last month and both stretches were less than 100 meters—has given me reason to explore different tire widths and tread patterns.

When it comes to 23mm road tires, all of the top-of-the-line stuff is so good there’s not a lot to argue about. And trying to get excited about a budget tire and figure out whether Brand X’s $25 60 tpi clincher is better than Brand Y’s $25 60 tpi clincher is a chore I can’t muster much excitement for. However, when it comes to 700C tires for use on dirt, well that’s a whole different bottle of beer.

Before I get to the tires in question, a few notes about criteria. While I’d love to put together rides that are 50 miles of nothing but dirt road, sadly, I haven’t had a chance to enjoy that flavor of Nirvana. My rides mix the paved and unpaved. That’s been true for the events that I’ve done thus far, as well. As a result, I look for tires that will roll well on asphalt. And while we keep hearing from readers who think I’ve got rocks in my head for running 50 or 60 psi in tires, I don’t mind reporting (yet again) that I really don’t like the way any of these tires handle on the road pumped to 30 psi. The squish factor makes cornering on the road dodgy. Also, the rolling resistance at ultra-low pressure increases so much that I struggle to get the bike up to 20 mph. Big knobs aren’t conducive to high speed on the road, either, so I tend toward smoother finishes. Finally, while I know all of these details add up to decreased grip in corners when off road, I don’t mind that. In fact, I enjoy it. I like pushing the bike to the point that the tires break loose and a 35mm tire on a drop bar bike pumped up to 55 or 60 psi does it in a pretty controlled way. These days, that’s about the only way I get that thrill.


The tire that convinced me to go with disc brakes on the Airheart is the Clement X’Plor MSO in the 40mm width. I’ve ridden this thing through sand, over wet roads, through mud, on roads, over singletrack and deep into clay. It performed admirably everywhere; I have to say that the wet descent of Bolinas-Fairfax in Marin County was an occasion where the tire surprised me with its terrific grip. The ride in which the tire most surprised me was at D2R2 when I found myself carving around the outside of other riders and I managed to pass people on moist dirt. Not bad. I’ve ridden the tire at a wide range of pressure; everywhere from 30 psi up to 80 psi (when I knew I wasn’t going to hit any dirt).

This is the tire I wish I’d taken with me on my recent trip to Hawaii. It would have been helpful at Kaena Point.

Clement offers the 40mm-wide X’Plor MSO in two casings, 120 tpi and 60 tpi. They report a weight of 384 grams for the 120 tpi variant and 480g for the 60 tpi version. My 120tpi tires weighed in a bit less, at 371g each. Clement does offer a 32mm version of this tire; I’ve yet to try it. These babies are a premium product and carry a premium price as well; they go for $75 each.


The other tire I’ve been using with regularity is the Continental Cyclocross Speed. This is the tire they recommend for hard, fast conditions, which pretty much sums up my riding when it isn’t all paved. Whereas the X’Plor MSO enjoys a multitude of very small knobs placed close together, the Cyclcross Speed is a traditional diamond-file tread with the addition of some modest knobs at the edges of the tread.

This is the tire I rode at the Rock Cobbler in Bakersfield. Pumped to 55 psi front and rear, it provided enough grip to give me control on all the dirt. At one point on the road I looked down and say 27 mph as I was trying to bridge groups; that was a move I’m sure I paid for later, but I’d never have hit that speed with a tire pumped to 30 psi.


This is a 35mm-wide tire with a folding, 3-ply, 180 tpi casing. Interestingly, it also weighed in at 371g, only this tire has an advertised weight of 350g. Despite having the same weight, my perception has been that this is a faster rolling tire (than the Clement), easier to accelerate and more nimble in tight corners.

I’ve ridden a handful of tires in the 28 to 32mm-wide range and none of them were quite beefy enough for the fire roads I ride. Sure, I’ve flatted both the Conti’s and the Clements, but because the terrain I ride so often goes from paved to completely questionable in less than 100 meters, smaller tires are problematic because they flat more readily. Anything less than the Cyclocross Speed at Kaena Point and I’d have turned around. At $49, this is a bit less expensive than the Clement. For the roads I used to ride back in New England, there are times when either of these tires would be overkill, but here on the West Coast these tires are terrific performers.

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  1. Jeremy

    The CX Speed is also secretly available in a 700×42 version, branded the “Speed Ride.” It’s my current favorite for mixed-terrain riding.

  2. Emil

    Another tire to throw in this mix is the Challenge Almanzo. At 33mm with latex tubes it is simply amazing, compliant and grippy. It is very similar in profile to the two tires you profile (and I imagine it behaves very similarly).

  3. Rod

    I loved my old CX Speeds to death. They’ve been replaced with Clement XPLOR, but the USH. Very happy with them for my dirt road rides where there will be fast paved sections, the central part is a bit smoother than the MSOs. They might be worse in mud and wet, but had no issues in our wannabe Roubaix race with flooded sections.

  4. Andrew

    The clement mso 32s rock. My go to tire for gravel. Fantastic on the rocks and shockingly fast on pavement. I don’t personally need 40s even for rough roads. I like 60 psi.

    The challenge almanzos have massive qc problems. Almost everyone here got them when they came out. Everyone had them delaminate. Horrifically badly made. Garbage. I feel bad for the almanzo guy, a local.

  5. Author

    Jeremy: I hadn’t heard about the 42mm version. It must be ultra-secret; it’s not on the web site. Sounds like it could be fun.

    Aar: Because I travel with this bike, I’m running the wheels with tubes. I don’t really want tubeless spooge all over the inside of my case and the rest of the bike. And trying to inflate tubeless tires with a mini-floor pump is unlikely to result in success or satisfaction.

    Rod: I plan to try the USH soon.

    Andrew: That’s a bummer to hear about the Challenge Almanzos. I’ve used other Challenge tires with great success. Let’s hope it was just one faulty run.

    1. Daniel

      You should try the USH, which is fabulous for mixed riding. The center ridge gives a fast pavement ride. It performs well on dirt and gravel and is a serviceable in mud, as Rod said. I’d like to try the MSO but they are more tire than I would need most of the time.

  6. Andrew

    Padraig: I don’t know if they solved the problem, but it was definitely multiple lots of tires, both in black and skin wall. I went through 3 of them (and a whole bottle of contact cement) before I gave up. Just be sure to buy them from a place that will let you warranty them if you decide to try them. I’ll be curious to see if anyone still has them at the almanzo this year.

  7. Brian

    Padraig: Great article but i’d like to talk more about your 50 miles of Dirt road. I live in Kalamazoo MI and there is a dirt road race called the Barry Roubaix out of Hastings, MI. They offer 24 miles, 36 miles and 62 miles. On the 36 mile course you gain 2,200ft. Its a killer race and 95% dirt road. Its turned into quite a race over the past 6 years with 3,000 racers this year. With it being so early in the year, I ‘ride’ the course instead of race it. Check it out

  8. souleur

    Sweet to think of these little tidbits, here in the ozarks, buddies and i have been really knocking the gravel roads out, loving it. If you think finicky tire choice is difficult for roadies….try the graveleur, it drives me crazy thinking and seems to be the single most important choice going. Conti speeds…are on my to buy list!

  9. Andrew

    Souleur: you know, honestly- it doesn’t matter that much. I’ve ridden all kinds of tires on gravel and they’re all fine. A lot of the newer riders up here at least totally overthink tire choice and pressure.

    1. brian

      In general this is true. You can ride anything but there are definitely tires that are more fun and less headache.

  10. brian

    Padraig: sorta off topic… what’s the best dirt route into Santa Monica /pacific palisades? From Reseda/Encino. Riding thru on friday.

    1. Author

      Brian: I’m sorry to say that I don’t know where to pick up the fire roads in Reseda/Encino. I never drop down that far; all my riding is confined to Dirt Mulholland and points south.

      Any of our Valley-based readers ready with a suggestion?

    2. brian

      No problem. Any suggested, or better, way south from dirt Mulholland? I can get to that from the maps/gps.

  11. Andrew


    Of course. I’m partial to Clements, and I know my tire pressure, so I’m as guilty as the next guy. I just get a lot of local guys, roadies, who want to start riding gravel and think they are going to die or explode if they ride the wrong tire or the wrong pressure. : – )

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