I’ve had the Mammut Rime Pro on test for a little while now. I’ve had a number of synthetic belay jackets in the last few years, my favourite of which is the Mountain Equipment Fitzroy Jacket. The Fitzroy has just the right amount of insulation for all but alpine winter climbing when it’s really cold. I often find the 900g to 1 kg belay jackets just too warm for use. Since I have used the Fitzroy extensively, my comparisons are mostly against that.
At insert 540g, the Rime Pro is a great weight for Scottish climbing all year round (40g lighter than the Fitzroy so pretty much the same). The 2 outer hand warmer pockets are raised to be harness friendly, although often you might expect to be wearing the Rime Pro over the top of your harness and using the 2 way zip to keep your belay device clear. There is a good sized chest pocket but it’s not map sized. A good adjustable hood with a stiffened peak completes the outside feature set. The Rime Pro uses 2 fabrics for its shell. The darker fabric on the arm tops and hood is a coated Pertex Endurance which is wind and water resistant whilst the rest of the jacket is Pertex Quantum, a lighter and more breathable fabric. This is probably the greatest difference between the Fitzroy and Rime Pro. The Fitzroy uses Drilite Loft all over, whilst this gives a more weatherproof jacket overall, it also traps more moisture inside so can be clammy when worn for a long time or layered.
I conducted a very unscientific water test but rubbing the 2 fabrics used on the Rime Pro plus the Drilite Loft used on the Fitzroy with a wet sponge and then leaving for a minute or so. See the results below.
The Rime Pro uses Ajungilak sleeping bag technology, (ajungilak are part of Mammut), and there is an element of ‘sleeping bag ness’ about it. It’s pliable, warm and comfortable so that’s a good thing. The Rime Pro is actually the most comfortable belay jacket I have worn and one of those that the more you wear it, the more you like it. Inside the Rime Pro has 2 large net pockets which are great hat and glove dump pockets, a small touch but a nice climbing feature. All jackets should have these 2 net pockets on the inside as they are easily the most functional of any inside pocket.
The Rime Pro is a fantastic pre and post race (mountain bike and fell) jacket where you could be wet and/or muddy, so not having to have the care considerations that come with down is a real bonus when you are desperate to get warm.
The Rime Pro is also a great jacket for climbing and general outdoor use. The less water resistant outer does make it extremely comfortable, but you will have to decide if it sheds enough water in the body for you but in sub zero or dry conditions it’s an absolute winner.