Thursday, October 23, 2014

Product Review: WTB Cross Boss tubeless CX tire

By:  Kirk Groves (@LSVLKirk)

Brad and I each bought a set of the WTB Cross Boss.

They're labeled 35mm but they measuring a phat 37.5mm installed on my Stan's Iron Cross wheels. I'm not aware of another tire out right now that meets my three criteria:  wide, aggressive tread and here's the key -- has a tubeless bead. Speaking of the bead, it's insanely tight, so tight I broke two plastic tire levers. I ran them at incredibly low pressures (~20 psi) just to see how low I could go -- I couldn't get it to burp. The sweet spot for me with these tires is with pressures in the high 20s.

Of course the tire is half the tubeless equation -- I can't vouch for how it'd do on other rims, especially one that's not tubeless ready. The tread hooks up well and is surprisingly quiet and smooth on paved surfaces.

The sidewall is soft for a tubeless tire but you won't confuse it for a tubular. I'll continue to race on tubulars but I'm running these for training and on the pit bike.

If you're looking for a tubeless CX tire give serious consideration to the Cross Boss. 


  1. How the heck did you get them mounted? I just got WTB Cross Boss 35mm in the post yesterday. I have IronCross rims laced to Chris King R45 Disc hubs.
    I tried today and couldn't even get close to getting them on! I also broke a plastic tire lever. After much more blood and sweat shed I threw in the towel. My hands feel destroyed, and I'm no closer to getting this setup.
    Let me know if you have any tips.

  2. Oliver, Here's a couple tricks for... mix and match from these.
    1) plastic covered metal tire levers
    2) mount the tire to another rim, put in a tube and leave it inflated at max pressure overnight to stretch the bead a bit
    3) get someone to help you -- a 3rd and 4th hand is very helpful on a bear of a tire
    4) warm up the tire before mounting, e.g., leave it in the sun or use a hairdryer
    5) talc or another substance to reduce friction

    Good luck!!! Kirk

  3. Man you guys were not kidding when you said these were hard to mount. It took me and my wife quite the battle just to get the FIRST bead on. I have never experienced that before. We did finally get one tire pumped up (with a tube) and this morning we are going to work on the other on. It has been sitting on the rim without a tube all night so hopefully it will be stretched enough to work with.