Over the last few years, the comfort, control and speed that wider road tyres afford have become clear and it is now rare to find anything narrower than a 25mm wide tyre on a road bike. We’re happy that the industry is moving in this direction, and we wanted to try some of the best tyres available at the truly girthy end of the spectrum, like the Compass Bon Jon Pass.
Measuring in at a mightily-plump 35mm wide, these tubeless ready tyres from Compass are revered in the randonneuring and gravel riding world and we finally have a set in for test.
The Bon Jons feature a heavily patterned tread that is claimed to improve control on the road in both wet and dry conditions. The centre has fine ribs that serve as wear indicators, the shoulders have a chevron, or ‘fine file’ tread to improve cornering grip and the edges have a thicker, flat section to protect the sidewalls from damage.
This flies in the face of convention, with most lightweight road tyres using a completely slick or very light tread, so we’re looking forward to seeing how these compare to some of our more conventional favourites.
We opted for the ‘Extralight’ version — in tan wall, of course — which use a casing material that is normally reserved for use in high-end tubulars. Compared to Compass’ standard casing, this option is said to be considerably more supple which should improve comfort and control, while saving approximately 50g per wheel.
However, the Extralight casing is said to be slightly more prone to sidewall damage when riding through jagged and rocky terrain. Since I'll be spending time primarily on the road with some brief gravel dalliances, as opposed to shredding the gnar on the Bon Jons, it’s a compromise I'm willing to take.
The tyres weigh in at 301g, which rather refreshingly, is a mere 2g within the claimed weight — 'optimistic' claimed weights are a pet hate of ours here at BikeRadar, so Compass earns brownie points for honesty.
On the note of honesty, it’s been noted by co-founder of Compass, Jan Heine that Compass tyres tend to expand a little and become wider with time. When mounted on a set of 21mm wide (internal) HED Ardennes rims, the Bon Jons measured 35.4mm at around 60psi.
Following this, in the good name of #bicyclescience, I inflated the tyres to their maximum pressure of 90psi, which ballooned them to 36.6mm. After a few hours at this pressure, I dropped them to a more typical running pressure of 40psi, where they eventually settled in at 36mm wide.
Okay, so how about that claim of a 35mm tire being faster than a 25? But our testing with wider tyres for mountain bikes and Heine's own testing with wider tyres on the road and gravel indicate that wider and more supple rubber is indeed faster on rougher terrain, and perhaps even on normal roads, too.
I will be testing this theory, running these tyres tubeless on Velocity Aileron rims on my longterm Velo Orange Pass Hunter test bike. Expect a review once I've had a chance to thrash the tyres on many long distance road and gravel rides in the coming months.
The Bon Jon Pass tyres with the Extralight casing are available direct from Compass in the US for $76 each, with the regular casing coming in at $57. The tyres are also available in the UK via Velo Vitality and Compass will ship to Australia.
Are you a wide-tyre evangelist? How plump do you dare to go on your road bike? As always, let us know in the comments below.
