Lapierre 2011: Pendbox and the DH

by singletrackjon 13

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.

Lapierre DH Team 2011

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 linkage driven shock pierces the downtube

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..

Comments (13)

  1. well if the euro keeps falling against the pound maybe it will just become very expensive!
    i want one

  2. Ideal for a SS DH bike then?

  3. shame they went for a carbon swingarm, it won’t like rocks…as I found out.

  4. I was just about to get a 2010 Lappy DH, now me thinks I will hold out for this baby. Looks sweeeeeet.

    Carbon is better on the rocks than a paper thin aluminium, just look at session 88’s for proof of that. Its hard to find an 88 with adowntube that doesn’t look like its been hit by a shotgun.

  5. SO its a floating bb like the Gt’s then?

  6. Integral seat clamp – why don’t we see these on trail bikes?

  7. What is the Pendbox, for those of us that can’t view the video at work?

  8. Happy now Jakester? 😉

  9. cough….I-drive…..cough
    up the midget ;0)

  10. “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
    The suspension is designed to work independently of this”

    So, how exaclty does the suspension work independantly when pedalling pulls it back (antisquat?) back to its sag position, surely that means it stiffens up and rises/steepens up under pedalling?

  11. It is designed to give MORE pedal feedback! Similar to vpp it is designed to pull the swingarm back to the optimal sag point… It’s the opposite of an i-drive as i-drive moves the bb backwards to cancel chain growth, but this moves forward to increase it.

  12. Yes indeedy – thanks very much! I didn’t expect you to update the main article, just a brief explanation. Cheers.

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