Gamux Bikes, designers of the only belt-driven gearbox mountain bike racing the UCI Lenzerheide World Cup DH this weekend, have two new mountain bikes under development. Featuring a unique cnc-machined rear-end that the Swiss brand has become known for, the Gamux trail bike delivers its 150mm rear wheel travel via a Horst-Link. Meanwhile, the 130mm travel Downcountry bike will see a full carbon construction, utilizing a lighter weight flex-pivot suspension platform.
Gamux Engineer, Pascal Tinner, gave us a run down of what’s to come in 2024.
Prototype Gamux All-Mtn Bike
Designed around a 150mm travel rear-end, the Gamux Trail/All-Mtn Bike will take a 150mm or a 160mm fork. A carbon front triangle is paired with cnc-machined chainstays, seatstays, link and shock yoke.
Pascal tells us that Gamux really enjoy working with aluminum, especially as the cnc machining they can do is a really accurate production method. It allows them to fine-tune flex characteristics through varying the architecture of the stays.
To increase or decrease stiffness of the rear-end in any way is not simply a matter of adding or removing material; it would actually require a different geometry in the structure of the stays.
The initial prototype saw a C-shape pattern in the stays, but this produced a rear-end that was too stiff laterally, and so Gamux reworked the design to produce the triangulated structures seen on the current prototype. This one is said to deliver more grip in cornering scenarios.
Pascal tells us Gamux is tuning the all-mountain bike to provide comfort for day-long pedalling missions on relatively mellow trails, as opposed to Bike Park, with a geometry that is capable enough to tackle steeper, more committing descents if required. He does say, however, that if you’re keen on hammering down enduro race stages, probably more travel and a slacker geometry would be beneficial.
With that in mind, this prototype has a 78° seat tube angle and a 65° head tube angle with a 150mm fork.
The bike will be available as a complete 29er, or as a mullet. Here on the prototype there is a flip-chip at the seat-stay. In 29er mode, the bike has two geometry settings available, but the mullet will have a single geometry, with the flip-chip simply correcting the geometry changes resulting from use of a smaller rear wheel.
Gamux will produce two sizes of the all-mountain bike, initially. Reach options will include 470 mm and 485 mm, with target customers in the 172 cm to 185 cm height range. Chainstay length will be frame size specific; around 445mm on the smaller frame, and longer for the larger size.
We are told the carbon front triangle weighs around 1 kg, with the frameset without shock will weigh around 2.6 kg. This is still to be confirmed, as Gamux is still working on tuning the carbon layup of the front triangle to achieve the desired flex characteristics.
The Gamux downcountry bike will swap out the Horst pivot for a flex-pivot, wherein engineered seat stay flex will make up for the lack of a pivot on the chainstay. With reduced hardware requirements, this is a much lighter way to deliver an efficient suspension platform, and for this reason it is used almost ubiquitously on modern day cross-country race bikes.
Pascal says the downcountry bike will have a more direct pedalling feel than the all-mountain bike. It will be designed around 130mm travel, with a 130/140mm fork, but it will be possible to run it with a shorter stroke shock for more of a XC setup.
Two frame options are planned for this one; the standard frame option will weigh in around the 2 kg mark, while a super-light version will weigh a bit less – how much exactly is still to be confirmed.
Gamux plan a pre-production run of frames this summer, with production bikes available to customers in early 2024. Pricing will come in at around the 5,000 CHF mark.