By Brett Ratner

I'll be honest. In my mind it takes guts to write a review of an off-road racing tire. I mean, if your last name isn't Nys, Compton, Absalon, Minnaar, or starts with "Van," there's a good chance you're not truly pushing the tread to its limits...and therefore aren't truly able to assess its performance.

So it was with a bit of trepidation that I put pen to paper to share some thoughts on Clement's gravel-oriented rubber.

I think what tipped the scales for me is that, since installing them in February, my X'Plor MSO tires (700x32mm with a 120tpi casing) have thrice excelled at their primary intended purpose (the 62-mile Barry-Roubaix, the 78-mile Grumpy Grind and the 103-mile Hellkaat Hundie gravel races). In addition, I've commuted on them in a blizzard, and had an absolute blast shredding some local single-track.

I've ridden them on pavement, chip seal, gravel, hard-packed dirt, mud, sand, crushed limestone, and grass...over roots and rocks, in rainy, snowy, and dry conditions, solo and in 20mph+ pace-lines. Push comes to shove, I'd feel comfortable running them in a dry cyclocross race.

The X'Plor MSO performs so admirably at so many things, I truly wonder if it's the most versatile tire available today. At the very least, I can confidently say that this tire took my harsh-riding aluminum cyclocross whip and turned it into an all-purpose, all-day bike that can haul ass TO the trail, as well as ON it.

The MSO has gotten its share of press in publications aimed at gravel and cyclocross racers. Since The Chainlink appeals to riders of all types, I figured it deserved some mention as a great "do-anything" tire.

Not just for gravel: the X'Plor MSO makes a great all-weather commuting tire too.

If you haven't heard of them, Clement is a somewhat boutique-ish tire company that has carved a nice niche for themselves in the growing US cyclocross and gravel racing communities (which are, in some respects, one in the same).

I've personally raced an entire cyclocross season on a set of Clement MXP tubulars, which are designed for mixed course conditions, ranging from dry to moderately wet. I also use a set of PDX clinchers (designed for muddy conditions) as my "pit wheels" and for the one or two rainy/muddy races we'll get in a year. Prior to last season, I raced the clincher version of the MXP.

I'm in no way, shape, or form a great cyclocross racer, but in my experience, the Clement's 'cross tires have proven to be durable, reliable, and provide confidence-inspiring grip on a wide-variety of surfaces. So, when it came time to gear up for some spring gravel racing, I thought I'd give Clement's gravel tires a try.

Gravel-specific tires are a relatively new thing (and to be honest, lots of people simply race/ride on "file tread" cyclocross tires). Also, to some degree, what makes for a good gravel tire seems to be evolving. But based on what I've seen, lots of companies start with a dry conditions cyclocross tire, add some puncture protection, tweak the rubber compound for a bit more more durability, and offer a tread pattern that gives you a fast rolling, semi-smooth center, with some small knobs on the sides for traction while turning. The MSO looks a bit "knobbier" than other offerings, but for the most part it follows this formula.

The center of the tread rolls smoothly while the moderately knobby sides increase grip in the turns.

The X'Plor MSO comes in two sizes (700x32mm and 700x40mm) and in two casings (60tpi and a more expensive 120tpi).

The 32mm size will fit any cyclocross bike, plus many road and touring bikes with cantilever or long-reach caliper brakes.

The 40mm size is ideal for the slew of new "gravel" or "adventure" bikes hitting the market. While it requires a bike specifically designed to accommodate wider tires, the 40mm's extra volume helps provide a cushier ride on rough surfaces, while also making the tires less susceptible to pinch flats if you venture onto trails with rocks and exposed roots. The 40mm MSO is a popular pick for the 200-mile Dirty Kanza gravel race, an event notoriously hard on tires (and riders).

I won't get into the particulars of thread count, but in most instances, a tire casing with a higher thread count will be more "supple" than a lower thread count casing and in turn may offer many advantages in the realms of comfort, traction, rolling resistance, and handling. As such, the 120tpi version is arguably the more desirable MSO model and commands about $20 in upcharge over the 60tpi version. Clement doesn't list MSRP on their website, but the street price for the 120tpi seems just under $70 and the 60tpi seems to cost around $45.

As far as performance is concerned, the MSO does everything you'd expect a gravel racing tire to do. For starters, it tracks beautifully and predictably on fast, sweeping downhill turns over loose gravel and dirt. It rolls surprisingly smooth and easy on pavement and hard-packed surfaces. It doesn't seem to get caked with mud (but that could have to do with the muddy conditions I've happened to ride it in, some types of mud are stickier than others). It feels pretty cushy over bumps too.

Another gravel/adventure-friendly feature is a puncture protection belt. A folding bead, meanwhile, gives you the option to stash a spare tire on unsupported rides where getting stranded isn't an option.

The X'Plor MSO feels right at home on dirt, gravel and crushed limestone, but does other stuff well too.

Where the MSO really shines is by doing things you wouldn't necessarily expect from a gravel tire.

For example, the Barry Roubaix gravel race ends in a town square, so the last few miles have a "criterium" feel to them. What I mean is 20mph+, right-angle turns on pavement, leading to a sprint finish. Coming in with a pack of riders, I recklessly threw the MSOs into corners and they didn't complain one bit. Considering the presence of side knobs, that's pretty impressive.

That same confidence-inspiring performance held true at a popular Chicago riding destination; the Des Plains River Trail. The MSOs felt rock solid on crushed limestone and hard-packed dirt, in a paceline through fast, sweeping turns. Then, when it was time to drop into DPRT's many singletrack offshoots, the MSOs railed tight, twisty corners with ease.

Roots, rocks and logs are admittedly a little much for the 700x32 size. So unless you enjoy fixing flats and damaged rims, you shouldn't plow into things with reckless abandon like you would on a mountain bike. The 700x40 will give you a little more leeway in this regard. So if your bike can fit the 40s, that's what you probably should get.

Even better, there have been rumblings that Clement is possibly coming out with tubeless ready versions of their clincher tires. If that's the case, the 700x40mm could be darn near perfect.

After 300 miles of harsh riding conditions, the front looks dirty and the little rubber "sprues" are worn off, but otherwise it appears practically new. The rear is starting to show a little more wear than a street tire might after the same miles, but not overly so. I'm guessing part of the MSO's grip comes from a softer rubber compound than a street tire. Still, I'd fully expect to get well over 1,000 miles out of the rear without significant wear. Considering their performance, I think that's a reasonable tradeoff. Also, no flats so far.

My only complaints have nothing to do with the actual tire. Instead, they pertain to some head-scratching decisions on Clement's part with regard to positioning of this product.

Specifically, Clement's 'cross tires measure 700x33mm (the largest allowable size in UCI-sanctioned cyclocross racing). Clement's other mixed condition tire, the slightly more pavement-oriented X'Plor USH, measures a hefty 700x35mm...probably the most tire you can cram in a standard cyclocross bike.

If bigger generally equals better in the segment, why design the dirt and gravel-oriented MSO as a 700x32? Why not make it a 700x35? Or why not make the USH (which is intended to straddle pavement and dirt) a 700x32 and make the MSO a 700x35?

I'm guessing there had to have been a good reason...perhaps to offer off-road capability to touring bikes while still leaving room for fenders? But for most gravel riders, my thinking is that with the MSO, Clement should have stuffed the maximum amount of tire possible in a standard-issue 'cross bike.

Also, and this is nitpicking a bit...but in researching all my Clement tire purchases, I've found their website and packaging materials to be a little long on marketing fluff (e.g. "blazing your own trail" and "getting outta' Dodge"), and light on details that matter.

For example, puncture protection is kinda sorta alluded to on the MSO packaging, but nowhere to be found on the website. How about a more detailed spec list? How about some bullet points or a chart indicating what Clement's tire offerings are meant to and not meant to do? If I'm gearing up for the Almanzo 100, how about telling me if I'd be happier with the extra traction of the MSO, or the extra volume and faster-rolling center section of the USH? This matters to me more than flowery explanations of airport codes.

All this aside, I'm really happy with this tire purchase. Granted, I'm curious to know how I'd enjoy running a 700x40mm MSO in the front (which a 'cross fork can generally accommodate) and the 700x35mm USH in the back (which should just squeeze into my 'cross frame). In theory, I'd get increased cushion all around, extra traction up front and possibly less rolling resistance in back. I'm curious...but not curious enough to ditch the tires I just bought, which are working out just fine so far.

In conclusion, if you want one single tire that you can hold its own commuting, on gravel, light single-track, and even in a dry cyclocross race, the Clement X'PLOR MSO could be your jam.

Visit http://clementcycling.com/ for more information.

About the Author

Brett Ratner (brett@thechainlink.org) began commuting by bike in 2005. Shortly thereafter, his interest in cycling expanded to century rides, bike camping and trail riding. The competition bug bit in 2012 and nowadays he races cyclocross, track, mountain bikes, criteriums and gravel for The Bonebell.