Although slightly off the radar for your average Singletracker, the big news at the launch of Lapierre’s ‘big mountain’ range in Chatel, France was the new 2011 DH bike.
Using a totally new frame design and suspension system the new DH has been developed with the help of Nico Vouilloz and Sam Blenkinsop. The big feature of the new frame is the Pendbox technology – to explain here’s a video of design team engineer Remi Gribaudo running us through how the system works.
[stvideo src=”2010/06/Lapierre DH.m4v”]
And now for those with a lack of video…
The Pendbox is Lapierre’s solution to the problem of removing the interaction between pedalling forces and suspension inputs when using a high single pivot design. When the rider is sat on the bike and the suspension is at sag position, the Pendbox, which is connected both to the frame and the swingarm (as a pendulum, hence Pendbox) moves the BB to the most rearwards position. If the rear wheel falls into a hole and the suspension extends, the BB moves forwards, and chain tension is maintained. The same happens if the wheel goes over a large bump – the BB moves forward and chain tension is maintained – the BB is only at it’s most rearward postion when the bike is at the sag level. Now, if the rider pedals the resulting chain tension pulls the BB to it’s most rearwards position and also pulls the suspension back to the sag position. In practice the movement of the BB is only around 5mm, but it serves to keep the chain from becoming slack, resulting in faster pick up when pedalling and it also counters the effect of pedal induced bob by pulling the suspension back to the sag position when the chain is under tension. Simple eh?
The suspension is designed to work independently of this, using the high single pivot plus a linkage to achieve what Lapierre claims is an optimised suspension curve and they’ve worked closely with Fox to this end. The design also gives easier access to the shock which is important to achieve the correct level of sag that the system relies on.
Despite our boy Jon being more used to the world of short travel, the new DH is impressive in action. There’s plenty of traction over roots, it does pedal well for a long travel bike and the sizing is a bit more normal than the 2010 version, which was extremely short – in fact the new large frame has a 20mm longer toptube than the old frame. It’s also dropped some weight over the 2010 model thanks in part to a carbon swingarm.
Apart from the Pendbox, the new frame has lots of nicely executed features such as internal cable routing, bump stop for triple clamp forks and inserts in the headtube let you adjust the headangle. It also features a very tidy integral seat clamp. In operation it’s nigh on impossible to feel the Pendbox moving and there didn’t appear to be any strange side effects due to the system, apart from the positives of a lack of chain slap and instant pick up when you begin pedalling. See the gallery below for more shots..