Donnelly Cycling formerly owned the Clement brand name, which has reverted to Donnelly not that the license has expired. The tread, manufacture and design was Donnelly, so it is fitting that the company can now proudly badge the tires as such. The BOS Tubular Cyclocross Tire follows Donnelly's naming process, taken from the airport codes of the areas exemplified. As such, the code for Boston's Logan Airport is BOS.

Initial impressions and marketing cues place the BOS in the "mud" category, like the famed PDX, but a closer inspection show a tire with more flexibility for courses that also favor sand pits and the type of variation that New England cyclocross courses are famous for. Under the canopy mud and loose materials can be present when wet or dry, and rough pavement or paths can connect technical zones. Bust out of the woods onto the beach and grainy sand, sometimes soft, sometimes lightly packed confront the rider. Unless you are racing in early Fall, when it could still be very dry from summer heat, courses tend to require a tire that can do it all. As a front tire, the BOS has a range from serious mud, ice and snow to but won't be out place on softer courses earlier in the season.

Whereas the tread of the PDX is very open with narrow knobs for excessive, sticky mud- which it handles as well as any tire ever has, it lacks some versatility on mixed terrain and tends to wear quickly when exposed to harder surfaces. The BOS features a fairly open knob pattern with large and firmer knobs that follow the shape of the casing. Those who rocked the green Michelin Mud will see some similarities in the pattern itself, but the BOS knobs are definitely more muscular. This translates into a solid feel when cornering on mixed terrain, with substantial grip, especially when run at the lower pressures safely conveyed by the tubular design. These shoulder knobs also serve to balance and provide traction in sand. The forward vector center treads are also beefy, if a little tall, so you can hold speed on hardpack or pavement straightaways, and delivers solid forward acceleration on soft or muddy areas. The overall pattern sheds mud very well, and as the knobs are more substantial than the PDX. is much more resistant to wear from hard surfaces.

The 700x33 BOS Tubular is UCI legal, running true to size. The construction of the tubular is different from what most tubular tires feature, as it has no internal tube that rests inside a casing. The casing here is sealed, with the seam under the tread pattern. This makes the tire easier to make perfectly round- a big advantage. By not using a super soft, race-only cotton casing, Donnelly creates a sealed system with much more sidewall abrasion resistance. It also is very effective with sealant, and as the sidewall is coated with a synthetic material, it won't rot or degrade quickly, so the BOS can be in play for several seasons of use, especially if you just use it as a mud tire and reduce overall wear on harder surfaces. That make the Donnelly BOS Tubular Cyclocross Tire a much better value proposition for most non-sponsored pro riders. It also favors riders who have less or zero experience on super supple tubulars, especially if they have more MTB experience where tread still drives grip and traction, even with tubeless designs.

The listed weight for the BOS Tubeless Cyclocross Tire is 386 grams, with the proviso that tire weights are generally +/- 8%. This may sound off, but if you have ever weighed tires, you know how much variation there can be- regardless of brand or model. . On the bike, you really don't notice the difference in that range, while actual performance, durability and strength are actually appreciated. Once the late season weather across the country gets more wet and the ground more soft the BOS Tubular could be in play for many riders, especially as a front tire, with the looming late-season New England races dictating for both front and rear options. A big part of success in cyclocross is your equipment preparation and willingness to experiment, so in the back of your head, though in September you may not be thinking about mud, get your BOS tubulars early to ensure you have them when needed.