For a couple races this season and plenty of training rides, I’ve given the IRC Serac CX a chance to prove itself on dry to damp conditions across grass, hardpack dirt, layers of leaves and pine needles and plenty of roots. There’s also been long stretches of pavement between the trails. Throughout it all, these tubeless ready cyclocross tires have proven to be a solid general conditions tire.
IRC has been in the tubeless game for a long time, offering road and cyclocross models since it first became a thing to ditch the tubes with skinny rubber. That history shows as the tires seat easily and hold air very well over time. They offer three tread patterns for ‘cross: this all ’round CX pattern, a mud pattern and a file tread “sand” pattern. Here’s how the CX faired on the course…
The IRC Serac CX set came in at 359g and 360g. Claimed weight is 380g, so actual weights much better.
Official size is 700×32. Mounted to the HED Ardennes+ rims (21mm internal width), the tires measure about 34.5mm wide at the widest part of the casing and 31mm at the edges of the tread blocks.
IRC also sent along their tire lever, which gets a handy little pointed prong on the back side to make mounting the tires easier. The wide HED Ardennes+ rims had proved to mount tires to in the past, and the IRC’s needed a little help from the lever’s clever design. The slight edge on the prong helps it hold the rim while pushing the tire over the wall.
From here, I added sealant and one tire seated on the first try with the Topeak JoeBlow Booster. The other tire required some time in the sun for the sealant to settle into the gaps a bit then a hit with the air compressor. That’s much easier than I was able to seat another brand’s tires on these rims, though, and I’ve heard from others that the Ardennes+ can be a challenge for road and ‘cross tires because they’re so wide.
The knobs are tall enough to grip, but not so deep that mud or grass accumulates. Granted, I didn’t use these in the mud, but anything wet that I rode through was flung off quickly, keeping the frame clear and rotational weight to a minimum.
Tread depth remains consistent from edge to edge. That’s good in that they roll fast through the straights and twisty turns, but I did slide out in a couple of really hard corners. Two instances in particular come to mind – one was a moderately high speed on dry grass coming around a 160º turn after a long straightaway that can be chalked up to pushing the tires a bit too hard. The second was an off camber, slightly downhill turn at high speed.
I attribute the second one more to the tire pressure being slightly too low for that hard of a turn. The ground was offering primo traction, and the tire stuck until it pulled away and burped a bit of air in the rear. For both races, I ran 38psi front and rear under my 195lb-when-kitted-out rider weight. As an experiment, I increased it to 42-43psi for a subsequent test ride and pushed it on hard, fast grass corners. They didn’t burp or squirm, and they felt more connected to the rim, but were a bit harsher on rough ground…just a bit, though, I was still banging the rims over roots. I found the IRC Serac CX to be a bit more supple than other tires I’ve run at the same pressure, which meant ground grabbing traction with the caveat that it might hold too tight for its own good on occasion. (NOTE: IRC recommends running 45-75psi, so my race pressure was below manufacturer’s recommendations.)
The lower knob height is more apparent from the side view. While they did their job in damp grass and over wet leaves, they really shine in dry conditions.
The center line is an angled paddle shape, and the overall pattern is directional – turn it one way for front, the other for rear. The image on the left shows it on the front of the bike, rolling toward the top of the page. Even on these wide rims, it has a nice round profile.
The Serac CX is a solid general conditions tire. It worked very well in damp to dry conditions with few surprises. Transitions from pavement to grass, grass to dirt, and back again were predictable and controlled. Only at the extreme outer edges of the tread did they lose grip. Taller side knobs could have helped, but perhaps at the expense of overall speed during normal cornering. That’s a trade off I’ll take to get a tire this fast across the usual spectrum of course conditions here in NC.
Retail is $59.90, sold direct by IRC on Amazon and in local bike shops.