The ASCENSION and BASIC ascenders are designed to be loaded in a direction parallel to the rope; if loaded at an angle to the rope, the cam may not correctly engage the rope and slippage can occur (See the technical notice, diagram 2).

-To limit the risk of slippage due to improper loading

  • attach yourself to the rope with two ascenders, each with its own lanyard,
  • load the ascender in a direction parallel to the rope,
  • if you cannot load the ascender in a direction parallel to the rope, clip a carabiner through the two top holes of the ascender, making sure the rope is captured inside the carabiner, or pass the rope through the lanyard carabiner (see diagrams opposite).


-Product information

Even though slippage can occur with any ASCENSION or BASIC ascender, it is more likely to happen with the first series of ascenders having a nylon trigger, introduced in 1998. Specifically, those with the following serial numbers:

  • B17 R from 97206 to 99109,
  • B17 L from 97253 to 99091,
  • B18 from 97308 to 99112.

The serial number is stamped on back of the product, near the top. In 1999, modifications were made to the trigger and return spring to help reduce the risk of slippage. But the downside of these modifications is greater difficulty in opening the cam and sliding the ascender down the rope.

If you would like, we will make these modifications free of charge to any ascender having a serial number within the ranges listed above. To have this done, send the ascender(s) to Petzl SAV, ZI Crolles, 38920 Crolles, France, or to the distributor in your country.

Petzl reserves the right to refuse to modify worn-out product.



Information is non-exhaustive, refer to the Instructions for Use and other I'D EXPERIENCE documents.