The UCI's unexpected announcement to allow disc brakes on 'cross bikes has caught many manufacturers off-guard but smaller outfits such as Germany's Tr!ckstuff have been quick to develop some interim solutions for those fortunate enough to have compatible frames.
The new Doppelmoppel straps underneath the stem and incorporates two small master cylinders, each actuated with mechanical arms to which the conventional brake cables are anchored. Hydraulic lines feed off from there to the respective calipers and it's then business as usual but with far more powerful and controllable braking than typical cantilevers.
The CNC-machined prototypes that were on display were admittedly a little chunky looking and it'd be nice to have a more elegant method of stem attachment than a couple of black rubber straps. But with that being said, it seems to work (we weren't able to test ride the setup) and it isn't as heavy as we would have thought at just 160g for the bare unit without fluid, hoses, or other fittings.
The folks at Tr!ckstuff tell us that they expect the final production version to shed another 50g or so, though, and it'll likely take on a more shapely form by then, too. Testing will continue through this 'cross season and Tr!ckstuff hopes to have the Doppelmoppel available for sale sometime in the winter for about €190, not including hoses, fittings, and calipers.
Tr!ckstuff says the Doppelmoppel will work with a wide range of disc brake calipers including popular models from Shimano, Hope, Magura, Avid, and Formula, although braking power, modulation and feel will obviously vary with the wide range of piston diameters encompassed in that list.
Not surprisingly, the Doppelmoppel will work best with Tr!ckstuff's own Cleg2 two-piece calipers, made of CNC-machined aluminum and available in nine different anodized colors. The company also revamped its existing Cleg4 four-piston caliper design, shedding a few grams while also increasing stiffness for better feel and power.