I’ve been at Öhlins for three years, always in the motocross department and TTX Flow is my first ‘drawing board to race track’ product so I’m pretty excited. In 2014, we hosted a MX test and the feedback the riders gave made us completely rethink the way a shock absorber should work on one of these machines.

In simple terms, a motocross shock has to deal with a complex, simultaneous set of forces which it struggles to cope with. From our early analysis we built a crude prototype which showed our new theory to work and gave us direction for a production unit. A motocross shock has ‘hits’ which disturb the system and therefore destabilizes the balance of the bike. It needs to ‘forget’ about each of these very quickly (in less than a 100th of a second). An example of this would be as a rider goes up the face of a big jump and also hits small, rough bumps at the same time.

We retained our TTX (Twin Tube) Technology but worked extensively on a new ‘check-valve’ system to balance wide valve openings and quick open/close actions to handle a large volume of oil flow. This required a new spool valve system as opposed to the more conventional shim-valve type. Basically it has been redesigned for each force upon it to be dealt with and ‘forgotten’ as quickly as possible, for fast recovery and keeping the stability of the bike.

The new system cancels out the smaller hits and keeps the chassis stable for the big jump. The test riders found that this was one major improvement, as was the stability of the bike over ‘braking bumps’ which absorbs the harsh hits and does not make the rear wheel go light. There were also big benefits under acceleration, filtering out bumps at the rear end.

Another major design criteria of the new flow shock was to make it much more rider/mechanic friendly. Maybe our previous shocks were a little complex for the average rider so we looked afresh at every component. The result is a shock with far less parts and complexity, which we have achieved without sacrificing any performance or functionality.

It is a nice feeling to be responsible for an all new motocross shock in this, our 40th anniversary year, when our first product and our heritage was created for dirtbikes!

Erik Hansson, R&D Engineer (MX Department)