The Actofive P-Train is a special kind of custom bike. Not a two-wheeled tinkerer's workshop, but a meticulously thought-out work of milling art. The passion project of a perfectionist mechanical engineer who puts function above all else. The centrepiece of the concept: the rear triangle. With the High-Pivot-Point, the main bearing of a single pivot is positioned well above the bottom bracket and the chain runs over a pulley above the seat stay. This decouples the suspension from drive and braking influences and enables a rearward-facing wheel lift curve for more sensitivity in rough terrain.
The disadvantage of CNC and High Pivot: the weight. However, thanks to the special production technology, this is kept within limits. For the main frame of the P-Train, named after a train in Helsinki by the way, two double-sided milled shells are glued together (see interview). Around 15 kilograms ready to ride is fine for a custom enduro bike, especially as the P-Train, despite the short rear suspension travel (145 millimetres), should give many a conventional bike a run for its money. There are only a few bikes available so far, and the P-Train will be available in a small series from the end of the year.
Cost pointaround 4000 euros for the frame without shock absorber.
Interview with Simon Metzner, the man behind the Actofive P-Train.
BIKE: Simon, you and your company design and manufacture components for vehicle and mechanical engineering. How did Actofive come about?
Simon Metzner: I believe that every bike-savvy engineer picks up a pen (or CAD) at some point. For me, the buzzword was "high pivot point". I thought it would be great to decouple the drive and chassis. Because the trails here in Dresden are always up and down. You need something efficient that still glides sensitively over obstacles. So I designed the P-Train. I've now got to the point where I manufacture the entire frame on my CNC milling machine. Design and production from a single source, so I can solve production-related problems right from the design stage.
Aluminium, milled. Isn't that heavy?
Not really. The frame consists of two thin-walled shells that are glued together. This creates a hollow profile, similar to a tube. This is stiff and relatively light. I can't keep up with the weight of modern carbon frames, but I have everything in-house.
What happens now?
So far, there are only a few bikes that I have built for myself and a few friends. I'm currently still working on some interesting details. But I think the time is ripe to go into series production with the P-Train CNC. That's why I'm planning a release at the end of the year. Who knows what will happen after that?
Adrian Kaether
Editor
