Should cyclocross races Down Under allow for wider tyres?
CX racers can rip through corners on their 33mm tyres - but would wider be better?
Photo: CX Down Under
Cyclocross racers are famously limited to knobbly tyres with a maximum width of 33mm, but in 2024 it’s not hard to find plenty of bikes with tyres that go wider than that. One of the great things about cyclocross is how inclusive it is, not least how able riders are to participate on bikes that aren't designed for CX.
In most races across Australia and New Zealand, riders with mountain bikes or gravel bikes with tyres wider than 35mm can still mix it up in CX racing. Depending on your local club's specific rules, you may need to either race in a lower grade than the fastest riders, or in an 'Open' category that's normally separate from any wider series standing. While it's great to be able to include riders on a wider series of bikes, it's not always easy to communicate that gravel riders and mountain bikers are welcome to participate in an Open race.
With most disciplines of cycling having experienced a severe dip in participation numbers after the COVID-19 pandemic, it’s understandable that race organisers may be looking at ways to cash in on the gravel boom as a way of boosting numbers and encouraging riders to try something different.
With that in mind, here are three options regarding potential changes to the maximum allowable tyre size in CX racing Down Under*.
Option 1 - Increase current tyre width limits for riders in non-Elite races.
At present, more formalised levels of cyclocross riding Down Under such as the Australian CX National Series and the New Zealand National Championships limit non-Elite riders to a maximum measured (?) tyre width of 35mm. At state or district level, tyres of 38mm are often allowed, with riders sometimes able to race on tyres measuring around the 40mm mark if they can convince a kindly commissaire to let them off the hook.
If you enter a race with tyres greater than that width, you'll need to enter an Open race that will allow you to win prizes on the day, but not compete for an overall series title.
Increasing that 35mm limit to 40mm or beyond encompass the most common tyre widths of entry-level alloy gravel bikes would make it much easier for riders just getting into the gravel scene to pin on a number and enter a local race (providing they can obtain a racing licence, of course). Such a change was implemented in the USA in 2020, with riders allowed to compete in the US age-group national championships with tyres measuring up to 38mm. That change has since proved to be popular with both riders and organisers alike, though given it was made in the middle of the COVID-19 pandemic measuring its impact on participation levels is tricky.
Tyres such as this 45mm WTB Riddler are now commonplace on new gravel bikes, but aren’t currently allowed in CX racing.
Photo: WTB
As an indication, these are the current tyre widths and price points for the entry-level gravel bikes made by six of the most popular bike brands in Australia and New Zealand, as well as direct-to-customer brands Canyon and Polygon.
Cannondale Topstone 4 ($2199 AUD) - 37mm
Merida Silex 2 ($1799 AUD) - 38mm
Specialized Diverge E5 ($2000 AUD) - 38mm
Trek Checkpoint ALR 5 ($2999 AUD/$3799 NZD) - 40mm
Giant Revolt 1 ($2499 AUD/$2799 NZD) - 42mm
Polygon Bend R7 ($2449 AUD) - 44mm
Canyon Grizl AL ($2049 AUD/$2349 NZD) - 45mm
Scott Speedster Gravel ($3499 AUD) - 45mm
Increasing the maximum allowable tyre width to 40mm or even 45mm would make it easier for gravel riders to enter CX races without having to buy a new set of tyres (and likely having to set them up tubeless), as well as increasing cornering grip without too much of a penalty in terms of rolling resistance.
Option 2 - Give gravel riders their own race category
Simon Eglinton of MOOD racing definitely brought the chonk to round 2 of the Crossfire Cup in 2023.
Photo: @rideadelaide
Another option would be to create a separate racing category for riders racing drop-bar bikes with tyres wider than the currently allowable limits.
One solution has been offered by the introduction of the gravel-specific CHONKLOCROSS category in Port Adelaide's Crossfire Cup Series. The brainchild of Adelaide gravel hound and photographer James Raison (@rideadelaide on Instagram), the CHONKLOCROSS category was first introduced last year for men and women and is open to all drop-bar bikes with tyres wider than 38mm. There was still an Open category available for riders on bikes with flat bars, but there were fewer entrants than in CHONKLOCROSS.
The category proved to be very popular, with over 30 different riders jumping into race CHONKLOCROSS over the four rounds of the Crossfire Cup - at least some of whom likely wouldn't have entered a cyclocross race otherwise. Having a designated grade for gravel bikes also meant that CHONKLOCROSS was able to be incorporated into the Crossfire Cup series standings, with an incentive for riders to race more than once and series winners awarded at the end of the year in the same way as the standard grades.
One consideration is that with all the other race categories competing for space on race day it forces riders of all abilities into the same category - so a newbie riding their gravel bike is likely to get smoked by an A-grade roadie who entered the same category. However, this would still be true if both riders had entered an Open race.
Option 3 - change nothing
Soft sand sections such as ‘Normandy’ at least year’s AusCycling National Series rounds in Perth could offer an advantage to riders running wider tyres at lower pressures.
Photo: CX Down Under
Of course, if you're more of a curmudgeon, you might argue that nothing needs to be changed at all. The current system allows for riders with tyres greater than 35mm wide to race in Open categories, and all that needs to be done to grow the sport of CX is for race organisers to advertise that option more prominently.
This option would preserve the traditional spirit of CX (if that's a thing that matters to you) while still allowing for new riders to try the sport out in an Open category that gives them the option of swapping to smaller tyres if they want to take their CX racing to the next level.
Additionally, it removes any complicated arguments over whether wider tyres will provide a significant handling advantage, as we saw with handlebars in the aftermath of Lillee Pollock’s disqualification from the 2022 AusCycling CX National Championships.
It’s all well and good for us to talk about these options, but we want your thoughts as well!
What's your opinion - should cyclocross rules be changed to allow for wider tyres?
*An important thing to note is that all of these suggested changes would be applied to riders in non-Elite categories. As riders in Elite, U23 and U19 fields compete for UCI-sanctioned national championships, it's only reasonable to expect those at the top end of our sport to adhere to the UCI limit of a measured width of 33mm. This is currently the case in almost all top-end races at club level Down Under, whether that's called A Grade, Elite Men/Women, or something else.
This discussion isn't about changing the top end of the sport. It's about making it easier for newer riders or riders from other disciplines to try cyclocross for the first time, or to grab a bike they already own out of the shed on a Sunday morning, pin a number on and get between the tape.