The following review was posted by www.bikehub.co.za
Onza has been around for longer than most will know, having started life in the late 80's producing tires, headsets, bar ends and other bits. For whatever reason (it was before my time) they disappeared from the scene until the mid 2000's when a Swiss-based company decided to revive the name.
Headed up by mountain bikers with several years of experience, Onza has launched a range of new mountain bike tires named after animals, localities and regions in Switzerland. "Onza" (Spanish for Lynx) itself is a cryptid cat said to be similar to a cougar.
We tested the 29" x 2.25” version of the tire with Onza's FRC 120tpi casing and RC²55a tread compound. The RC²55a designation means that there is a harder, 65a durometer rubber in the centre for durability and reduced rolling resistance, while a softer 55a compound is used on the outer knobs for improved cornering traction and grip. The 120tpi (threads per inch) offers a lighter, more flexible and supple casing. It is a Tubeless Ready (TLR) casing which means it can be converted using sealant, but it doesn't carry the same weight penalty of a full tubeless tire.
Its tread pattern reminded me of the popular and much-loved Maxxis High Roller, with wide horizontal central blocks and large angular, aggressive side knobs.
On the Trail
Mounting the tires and setting them up tubeless was easy and they inflated first time using a Topeak JoeBlow Mountain floor pump on the 3 different wheelsets (AMC Wide Lightning, AMC Carbonator and derby rims custom wheelset) they were fitted to.
Thanks to its full-size width and aggressive tread pattern the Ibex is not a fastest roller, but it was never designed to be. There are no intermediate lugs between the harder centre and softer side lugs, but the transition is predictable and when pushed hard the side lugs catch the slide before it gets out of hand and affects confidence in the tire and it's grip. I found the aggressive square-ish side lugs help you hit corners and off camber sections faster and with more confidence than you would on most tires.
For those looking for a bit less rolling resistance, I think pairing an Ibex out front with an Onza Canis in the back will be a great combination. I am however more than happy to sacrifice some of that speed when climbing and pedalling along for the added grip in the fun stuff.
The Ibex descends with impressive grip levels and confidence. It does not mind being pushed hard. In fact, that's when this cat comes alive. The supple casing with the tread design offers great grip, whether the trail is soft and loose or wet and muddy.
From the Manufacturer:
Intended use: AM / END / FR / DH
The IBEX (or Capricorn) is known for fast, smooth and safe locomotion in mountainous terrain, and the tire named after it is no different: Thanks to its wide open tread, you do not need to compromise on either loose gravel or in wet conditions. No trail is too steep, no section too narrow and no root too slippery for this all round tire.