It’s no secret that the team at CycleTechReview.com are big fans of Clement’s range of CX clinchers; of those, my absolute favourite is undoubtedly the mud plugging PDX. If I had to race a whole season on a single clincher tread, that would be my choice; what you lose in the dry, you more than gain in the slop. Accordingly, I awaited the arrival of our test pair of PDX tubulars with bated breath. They would be going up against the benchmark mud tub, the FMB Super Mud, and also a pair of green Michelin Mud treads on a FMB carcass.
Named after the epic cyclocross conditions of Portland, Oregon, where rain and plenty of mud create some extreme conditions (and our US contributor, Dan Saunders plies his trade), the Clement PDX Tubular has an innovative tubeless casing. The lack of an innertube in these tubulars, instead relying on an airtight casing, is a clever move, saving weight and offering further resistance to punctures, especially with the straightforward addition of liquid sealant.
Another innovation is the sidewall, which is coated with rubber (making no additional sidewall coating necessary) and is therefore much more durable than with traditional cotton tubulars. The tread is manufactured integrally with the tyre so won’t peel away or detach from the casing. The Clement manufacturing process produces very uniform straight tyres making them much easier to install, as a straight tyre means a more even layer of base tub-tape and an easier surface to glue.
The familiar PDX tread is ‘an all-around performer with a particular love for mud’ according to Clement. As with the clincher we tested previously, the centre knobs are aligned to give you hard pack or pavement speed, whilst some aggressive looking side knobs are designed to provide cornering grip. Even the leading edge of each knob gives has been designed to deliver extra traction for acceleration, whilst the wide spacing is designed for mud clearing. So it all sounds pretty good, but does it work?
Out of the box a couple of things strike you about the PDX tubs. They are clearly machine, rather than hand, made. However, they are still very supple. They do seem quite narrow when you are used to their voluminous clincher cousins but this is undoubtedly due to the real need for a racing tub to measure the UCI legal 33mm, to which the clinchers we have tested don’t even come close to. They are also inherently very straight, much more so than the handmade alternatives, which helps with mounting. Finally, they were super tight to mount on my Ambrosio rims, one of the hardest sets of cx tubs I have ever mounted, even after we’d made sure to stretch them for an extra long time before gluing up with 3 layers of glue and a layer of Jantex tape…
Once riding, I found, as with the PDX clinchers, that these are tyres that need very low pressure to be at their best. I ran 21/22 psi (and with this rider weighing 80kg) where we were running 23+ psi in the Muds and the Greens on the same track. Once the pressure is tuned, the performance of the PDX was indistinguishable from the two artisan tubs, with the benefit of their being cheaper and, we expect given the design and sidewall, more durable.
They grip hard in the turns and off camber sections, plus they are not phased by deep soil or mud. Critically, like all great mud tyres, they don’t ball up and are adept at throwing off any accumulated mud. In this respect I actually believe they are better than the Super Muds, leaving me with a noticeably cleaner bike, which is critically important to the privateer racer.
Overall they deliver a tangible sense of confidence and control, enabling tighter turning and later braking. At the end of the day, you can’t ask for more than that from a tyre and come the next muddy cx race (which is to say, the next race with the present weather conditions) there will be quite a fight at CycleTechReview.com HQ to see who gets their hands on these superb treads. Chapeau, Clement!