Sram Truvativ Hammerschmidt
- by Christopher Jones
- Published: 13 September 2008
The Hammerschmidt has been one of the more exciting new releases in the bike world starting with blind fold tests for selected journalists and a marketing campaign that cleverly kept details of the planetary drive system under wraps.
Prior to Eurobike, the Hammerschmidt was released and exploded isometric diagrams showed the inner workings and give away its secret which matched expectations. A selected few were able to try and test it however Eurobike was the first time that trade and even interested bike brands could try it for themself. Scott for example are releasing a 2009 model of the Genius with Hammerschmidt whereas some other brands such as Specialized are not (at this stage). The Hammerschmidt system requires ISCG 03 or ISCG 05 bottom bracket fittings, this includes three mounts for chain guides and tensioners on Downhill and freeride bikes however is not common and means that many brands have to redesign their frames to include this system.
The Hammerschmidt was available to try as well as to take apart. Gear changes are via a handlebar mounted thumb operated levers. I was initially confused by this and first tried my fore finger (changing down) and thumb (changing up) until I realising both levers are thumb operated. Gear changing is easy however does require you to stretch somewhat in order to change back down a gear. The ride is comfortable and quick, Hammerschmidt is a robust gear solution with two gears (1:1 and 1:1.6) with current application for Downhill and Freeriding.
The gears (image top right) are activated using the ‘clickers’ that are marked in yellow. In the standard gear, the clickers move back and forth as the cog revolves around it. When the gear is changed the yellow ‘clickers’ lock into place and drive the planetary gear system. In the standard gear there is a slight clicking feeling however this does not badly impact upon the ride feeling.
Hammerschmidt offers a compact and robust front gear system that is only marginally heavier than the derailleur and chain rings that it replaces. Gear change is possible while pedalling or stationary. It offers better ground clearance and claims to require less maintenance. It was infact simple to take it apart and rebuild the four main parts.
The Hammerschmidt is being taken seriously by the bicycle industry and 2010 should see the Hammerschmidt offered as standard on many DH and freeride mountain bikes. 2009 is an important first year to see whether the Hammerschmidt has a chance to replace the front derailleur.