MATTER of FACT: Making Sense of Tubeless and Tubular Tires for Cyclocross

Welcome to the third of an ongoing stream of posts that share questions I receive from members of the riding community about items of interest to the collective. These posts are primarily about MATTER – the technologies we engage in the act of cycling – but anything and everything related to cycling is fair game, including the stuff I’m definitely not a real expert on, like cognitive science!

Holler at me, I'll run with questions that spark my interest and are likely to do the same for others. ‘MATTER of Fact’ is a tongue in cheek thing. There are/no facts.

Keith: Cyclocross wheel/tire question, I need all the help I can get trying to keep up with you at Nationals [no I didn't add this! Ed.].... I have one bike, three sets of wheels. How do you pick the tire set up? Tubeless with drys carbon tubulars with muds, aluminum tubulars with mixed? I value your opinion, as from what I can see you've gone through your fair share of wheel/tire combos.

I think this question is relevant to many cyclocross riders, from those new to the discipline to veterans, as we're at a moment in time where folks are transitioning to disc bikes and trying to figure out how to move forward with their wheels and tires. - Note : this piece was updated following the 2019 CX season

I've faced this very decision process myself, complicated by the use of rim brakes with carbon and aluminum rims of slightly different widths. Fun! Not so much.

For the sake of brevity, I'm going to assume you want to stick with your wheels as they are for the foreseeable future, so this is simply a decision about which tires to put on which wheels. I'll assume you have each tread type in each format type (tubular, tubeless).

I'd start with thinking through two approaches and their associated scenarios:

1. The A-race/s 'eggs in one basket approach'

2. The 'every race matters long-game approach'

You'll see that I'm going to recommend shifting to a two-tire approach for your wheels - intermediate/normal and mud - versus the traditional dry (file tread) / intermediate/normal / mud tire trio that is the norm in elite and professional racing. Beyond the reasons I discuss below, this approach has the advantage of reducing stress in the decision-making process, which I feel is more important when we look at it holistically, with a view to performance, quality of life, and sustainability in the sport. That is, I feel the two-tire approach contributes more to our enjoyment of the sport and will ultimately yield better performances overall than the three-tire model. Since most of us do cyclocross for fun, and we'd like it to remain this way as we progress (in whatever ways we value), I feel the two-tire approach is the best way to set ourselves up for meaningful success. After all, fun is fast.

I'll go on from here to refer to intermediate/normal tires as 'normals.' This is because I don't want to continue to perpetuate the three-tire model, with the intermediate being in the middle. From here on, 'normal' tires are the all-rounder treads we'd use most of the time, including for training through summer and fall.

The A-race/s 'eggs in one basket approach'

If Canadian Cyclocross Championships is your A race, and you're willing to sacrifice some performance in the lead-up to the weekend, we must be honest about what we should expect: wet conditions, mud. If you want to have a setup that is absolutely optimal for that weekend, it's probably mud tires on carbon rims (I'm assuming you are on disc brakes here, or that there is no braking difference that matters to you between your wheels).

On this scenario, the carbon wheels will probably sit around most of the season. That might be a blessing in disguise, because if you use your tubeless wheels as your primary set, you can run a normal tire on them as your default, and change to muds for the weekends you know will be muddy, or stick with normals if you think it'll be borderline

Normals and muds would be your focus, with drys on the periphery for the rare occasions where they really will be worth mounting to tubeless wheels. Ideally, they won't be necessary at all, when you weigh the speed benefits normals give you over file treads. Those racing real sand courses will see far more value in the three-tire model; this is not the reality for anyone racing in North America, as far as I know.

This would leave your aluminum tubulars; what to mount? I'd go with normals on these, because your carbons would be locked up with muds, rendering them useless as back-up wheels on dry or fairly dry weekends.

The 'every race matters long-game approach'

Another approach, what I'd personally do, would be to mount full muds to the alu tubulars, and normals to the carbon tubs. I'd use the intermediate tubs as my primary race wheels, with my tubeless wheels running tires to match. I would fight the urge to mount file tread/dry tire on occasions that were looking borderline at home before heading to the race. Why? Because if I suffer a puncture in training or during the race on my normals, I'll be forced to run a file tread, which might be totally inappropriate. It's always better to have your spare wheels matching those on your bike in terms of tread style so that you don't make a bad decision, such as convincing yourself you don't have a slow leak 5 minutes before your start because you don't want to run the wheel with the inappropriate tread.

We always have to consider what matters most when we're in a state of stress and anxiety at the races, and how we can manage all the elements within our control in order to be as calm and focused as possible.

For a mud weekend, I'd go to full mud on the tubeless, a different tread than the tubular, and see which worked better. For example, the current (2019) Specialized Terra Pro (above right) is a better mud tire for Canadian Championships in Peterborough than any tubular mud tire I've used or seen. I'd run the Terra as my primary setup, tubulars as backup.

For a normal tubular tire there are many great options, which I won't get into. On the tubeless side, I've been really happy with the old Specialized Tracer (above) and I like the current version (right) a lot too. In 2019 I confirmed that this new Tracer isn’t great in the wet in the wet, however, so you might be pushed to your mud tires sooner than if you chose the Vittoria Terreno Mix as your normal tire, which I'd like to try. I’m not the only person who’s saved the old Tracers for mixed conditions days. I run the old Tracers on one bike, the new ones on the other bike, and choose between them based on conditions. On somewhat wet days I’ll start on the old Tracers, and run Terras on my second bike. As opposed to Specialized’s two-tire system, Vittoria continues with the traditional three-tire approach.

I've spend lots of time on the tubeless first generation Terra, the current version, and the Terreno Wet (below). All three tires are great, and subtly different. Vittoria builds their tires a little more robustly than Specialized, meaning they are a little more puncture resistant, and, on paper, perhaps a little slower rolling at low pressure. However, in use, I feel the Vittoria rolls really well, and I suspect this is down to its compound. The tread is more of an all-rounder mud than the older Specialized Terra, which is more 'pure mud'.

By this I mean the knobs are tall enough and openly spaced enough to squirm on hard surfaces and create a lot of rolling resistance. The Terreno Wet is less like that, meaning it is less tenacious in terms of grip in the most gnarly mud, but is better suited to medium-gnar mud, especially when there are embedded rocks and other hard objects to contend with; the extra casing protection helps prevent punctures. The current Terra squirms around less than the old one, and the tire works extremely well - better than the older version - in full gnar mud. It’s also more stable on harder surfaces. I love it.

To sum up, from a principles basis, I recommend focusing on a two-tire approach to setting up your cyclocross wheels, where the specifics of which tires go on which wheels comes down to where you want to place your performance priorities.

I'd like to stress that all these decisions really need to be informed by careful thought around the realities of amateur racing, not the ideals reflected by the pros. Their choices of equipment are relevant to us, but we shouldn't always try to replicate what they're doing.

A final thought when considering tire/rim combinations: in grippy conditions there is such a thing is too much grip. This means a tire can track too well to the ground for the pressure you're running, which leads to tire folding and casing damage in the case of tubulars (mainly, but tubeless too), and potentially burping (loss of) air in the case of tubeless.

So, as a principle, it's important to know that a certain amount of slide is valuable when running low pressures on grippy surfaces, in order to get the most suspension and speed out of your tires, while avoiding overloading them in the most demanding turns. Sometimes this equates to a decision between mounting file treads on-site, or upping the pressure in a normal tire. As always, it's a matter of weighing compromises.

UPDATE: During the 2019 CX season I ran an experiment: I used tubular glue to adhere my tubeless tires on 4 sets of wheels! Stay tuned for a post about how this worked out!