Finnish firm Avial is launching a commuter e-bike made from aircraft aluminium alloys which are glue-riveted instead of being welded. The firm says this approach results in a stronger frame with ‘elastic’ properties that dampen road vibrations and also keeps costs down.
There are two main aluminium alloys in use in the bike industry today – 6061 and 7005. To the first of those, Avial has added alloys 2024 and 7075, which are used in the manufacture of aircraft fuselages and wings.
While these alloys have the best fatigue strength ratings, they are also difficult to bend and weld. The patent pending frame of the Avial commuter e-bike solves this problem through the use of hybrid glue-rivet technology – the same approach that is used in the aviation industry.
Avial says this technique also makes it easier and cheaper to manufacture the frame.
A spokesperson explained: “Hybrid glue-rivet technology is a sustainable technology that protects both the environment and workers.
“Compared to welding, there are no high requirements for the preparation of the surfaces of the workpiece, there is no light radiation, vapours and sparks, no thermal stresses arise at the junction point, there is no need to re-heat the frame after welding to restore the strength properties of the aluminium alloy to the T6 state, and workers in production do not need any special skills.
“At the same time, the joint obtained with the help of hybrid glue-rivet technology is not less strong than the welded one, and during long-term operation, it is always possible to visually control its quality.”
The latest version of the Avial commuter e-bike is equipped with a 250W rear hub motor with a built-in controller and a 504Wh battery.
More powerful motors are also available, while a universal mount makes it possible to equip the bike with batteries up to 1176Wh.
While a mid-drive prototype has already been constructed and put through its paces, Avial is awaiting the removal of Covid-19 restrictions before road testing its new commuter e-bike.
The price is currently listed as €1,090, excluding VAT and shipping, with deliveries scheduled for the end of this year.