UKH

I bought an ALPINE UP last summer to try on multi-pitch routes for a bit of extra holding power whilst belaying, it generally worked well on a 3 pitch abseil from the Vajolet towers with some new Beal Cobra 8.6 half ropes.

Later on the trip I did a ~25m abseil off the top of the Torre Piccola di Falzarego, and the sheath of the almost new Cobras was slipping & bunching up into the device when abseiling, it was getting so bad that I almost couldn't move and I had to stop several times to push the sheath down the rope core. The Cobras are Unicore too, so the sheath is supposed to be glued to the core.

Not sure what was causing the issue - potentially the ALPINE UP doesn't like abseiling on twisted ropes? 
Has anyone else experienced similar? User error, or just inherent weakness of the device?

Could this not also be a rope problem rather than a belay device problem?

This sounds more like a rope issue to me but I could be wrong 

Have used two different Alpine Ups on many different ropes and never experienced this. I've been using one for 10 years or so.

Not used that device or have those ropes but we've never had that happen with any of the rope / device combos we own.

Was the rope wet? Have you tried a different device? Have you tried your Alpine up on a different rope to see how it works?

I'd tend to agree with the other members that it sounds more like a rope issue. Either way, that's no good

Not sure how the belay/abseil device could be the issue, they're all fairly analogous in that they bend and possibly pinch the rope over some metal, with a lot more friction/grab on the sheath than core - from an original sticht plate, to an Up, to a Grigri, to a whatever. 

The sheath slipping isn't generally a big problem in this scenario with modern rooes. But given unicore construction should bond/glue the sheath to the core this *shouldn't* be a consideration here.

I think you should contact Beal ASAP! About this rather than asking on a forum

customerservice@beal-planet.com

Perhaps ask the manufacturer ?

I've abseiled on a pair of Cobra's using the Alpine Up with no problem. It does sound like it's a Beal issue rather than an Alpine Up issue.. 

I once left my 10.5mm (remember them?) sport rope on the Marlolata abseil at Swanage. Got back from a climb to see someone majorly strugging to get the rope into their old-school spring stichplate followed by very difficutl abseil. The sheath got so stretched and loose around the core it was retired afterwards.  So you can mess up a rope with the wrong combo on abseil, but wouldnt think cobras and the UP woudl be a problem.

Were you abbing in the 'click up' position, or reversed with a prussik? 

Thanks all for replies, good to hear it's not a common issue. I haven't abseiled on the ropes since on another device but could try when the weather is a bit better. I could also try to use the Alpine Up on some different ropes to test.

I was abseiling in clicked up mode with no prusik.

Cobras weren't wet, but were potentially twisted.