After reading how popular the Clement MXPs are as all-around cyclocross tires, I picked up a pair in hopes of upgrading my stock Specialized Tracer Sport tires. I also read about many riders’ positive experiences (a few negatives too) with riding these tubeless, so that was my intention, especially after having picked up a set of Stan’s NoTubes Iron Cross Pro wheels which are specifically designed for tubeless CX racing as it has wide shoulders to limit the chances of burping. Consider me “new school”, as opposed to “old school” and getting tubulars.
For the number geeks like me, here are some numbers:
- Measured weight: 336g and 350g
- Measured width: 36mm and 35.2mm
- Claimed width: 33mm
I couldn’t find any official claimed weights on the tires, but Internet peeps have been weighing them in consistently between 335-350g. The measured tire widths will always depend highly on the width of the rims (specifically the inner width) that you install them on. The Iron Cross rims have a very wide internal width of 20mm that gives tires more volume and a less bulbous shape.
Tubeless setup: The tires did not sit tight enough on the rim to be able to use a standard floor pump. For one wheel, I used our shop’s compressor; for the other, I tried out the Bontrager TLR Flash Charger pump for the first time! And it worked without a hitch. The gush of air is strong, but not as fast as it comes out of a compressor or CO2 canister — it’s a steady controlled flow, which is really nice.
Why tubeless? Well one general advantage of running tubeless tires (road, mountain, or cyclocross) is the ability to run lower tire pressures without worry of getting pinch flats. As a lightweight rider (145 lbs), pinch flats have never been a problem for me on the road or in CX. I have raced my Tracer Sports at around 28psi (front) and 32psi (rear) multiple times without any pinches. Those are definitely on the lower side of tire pressure in CX. The hesitation in the CX world in moving to tubeless is the combination of low pressure and low volume, as that can often lead to “burping” of air if the pressure is too low and you hit a bump or corner too hard. I’ll probably test the tires down to 25psi at the lowest to see if that is reliable.
Another reason is not worrying about tire punctures. Since CX riding is primarily off-road, there are plenty of opportunities for little splinters, thorns, or rocks to penetrate the tire. On my mountain bike, I have gotten 2-3 punctures in the middle of the ride, but they sealed up quickly with the Stan’s sealant and I got to keep riding without missing a beat! On my Tracers with tubes, I did have a small thorn puncture my tire and tube, causing a small leak that I found later. Sealant is really capable in sealing up holes and even cuts sometimes.
I actually only just installed the tires yesterday, so I can’t say much about ride characteristics! Today I’m going to see how well the tires sealed up and how much air they held. There were a couple spots of weeping sealant bubbles, but I think it’ll be fine *crosses fingers*. CX Nationals are in one month so I’ll definitely be training on our local course and will try to push the tires to its limits, although I’ll probably hit my limits first! An update to this “review” will come later with actual ride experience.