Actofive, the German bike brand behind the P-Train
, are launching a crankset. The crank arms are CNC machined, giving them that woodgrain-like machined aesthetic, and allowing them to be made in-house in Germany. Interestingly, to make the crank arms hollow (for the best strength-to-weight ratio) Actofive settled on a two-piece design for the crank arms themselves. Each arm is made in two halves, both machined from a block of solid aluminium, then the two halves are bonded together, a bit like the two halves of an easter egg, with a hollow cavity in the middle.
CNC machining and bonding are techniques Actofive are familiar with from their 7075 aluminium P-Train trail bike
, so they wanted a crank to match the bike and make use of that expertise.
"Analogous to the construction of the frame, they feature a two-piece hollow construction from CNC machined thin shells of high-strength aluminium... This ensures an ideal application of forces within the structure and a cool look," says Simon Metzner, Actofive's founder, "but on the other hand, it complicates the process, because of the manual bonding process in addition to the machining process of all components. I am convinced that this effort is worth it in terms of the above-mentioned targets."
After machining, the two parts are anodized in black or silver before being bonded together. This makes it possible to have two-tone black and silver arms by using one of each colour.
Making one crank (both arms) apparently requires about 3.8 kg of aluminum and two hours of machining. Remnants are recycled professionally. The bonding is done by hand and takes about 30 minutes.
For the interface, Actofive have made life easy for themselves (and potentially for customers too) by using the same 29 mm spindle diameter as SRAM, allowing them to use SRAM DUB bottom brackets. Similarly, the three-bolt chainring interface makes it compatible with SRAM chainrings, and along with the SRAM-style integrated crank puller, means removing and installing the crank arms or chainring requires no special tools. Bearing preload is adjusted with a threaded collar (blue or black) on the left-hand side of the crank.
The crank is available in two lengths: 170 mm or 165 mm. "We love fast turns, lean angles and a low centre of gravity," says the press release. "For this reason, we prefer to ride short cranks."
The spindle is interchangeable and two spindle-lengths allow the crank to be used with a 73mm BSA bottom bracket (Q-factor 168mm) or a 68mm BSA bottom bracket (Q-factor 163mm). The latter makes it compatible with many gravel and CX bikes.
With a claimed weight of 475g without a chainring and a price of 690 EUR (621 Euros for pre-orders), you can get a slightly
better cost-to-weight ratio elsewhere (a SRAM X01 carbon crank weighs 415g and retails for €610), but the weight is still impressive for aluminium and those aesthetics are unique.