What a 100 J impact rating means, and what it doesn’t
October 17, 2026Venn has run its own development programme since 2008. Its landmark is the filament-wound carbon rim, which we pioneered (Eurobike Award 2015), and the granted patents we held for it, TW I607894 and TW I634964. What riders pay for Venn goes back into this work.
Strength: our pass marks, above the standard
We work from the standards themselves, bought from their publishers rather than read in summaries: ISO 4210-7, whose clause 4.6 is the UCI’s wheel impact test, at 40 J. Venn sets its own pass marks well above that: 100 J for road, gravel and XC rims, 130 J for all-mountain and 150 J for downhill. A pass mark is the energy a rim model must survive in the test, not the point at which it breaks. Our rims are tested to these requirements, and the programme also covers fatigue (a million cycles), spoke hole pull-out, lateral stiffness and heat. Our technology page shows the results for the 520 TCD UL.
Aerodynamics: where it started, and where it is now
Our aerodynamic work began in 2012 with CFD on a national GPU supercomputer, and in 2013 we tested in the low-speed wind tunnel in San Diego. During our three years at Flanders Bike Valley in Belgium we used its wind tunnel several times, testing wheels, complete bikes and a rider on the bike, to understand the aerodynamics of the whole bike and of each of its parts. In 2018, with National Cheng Kung University, a genetic algorithm driving a CFD solver searched 675 profiles for the Var 77, with the shape left free. No bicycle rim had been designed that way before. The work continues on our own workstation, where we model the whole wheel, spokes and hub included, and check the method against published wind tunnel data for a reference wheel.
The Helix-01 hub
We took the Helix-01 from an early prototype to the hub we sell: the angular contact bearing seat and its interface, the preload system, the shell, the axle and a one-piece alloy freehub, refined through live testing. It engages through 72 teeth on a helical interface, and it is a hub only Venn has.
Materials and teaching
From 2019 we ran government-funded thermoplastic composite research in Belgium, shown at JEC, and we have given guest lectures at National Cheng Kung University. Venn’s work has won ten awards since 2010.
