I have a set of those for my F8. They were a special order item from Wunderlich, took about 4 weeks to arrive in the UK. You can
use them with the stock mudguard, despite what their CYA may say.
- Better on ice and hard packed snow than knobblies, but not a patch on spiked tyres.
- Worse than knobblies in thin, fresh, loose snow.
- Fit them to sports touring tyres, rather than knobblies (or the chains will just work their way between the knobs and be next to useless). I haven't tried them with something like a K60, but they might work well.
- Fitting them is such a ball ache, even with a centrestand and front jack, that you'll often be tempted not to fit them as "it's only 300 yards to the main road and that's clear, I'll just take it easy". This is a bad idea. There is little more frustrating than being pinned under a bike thinking, "if only I hadn't been lazy and had fitted the chains..."
My verdict: The best "get you home" measure you can carry on a bike equipped with road tyres.
These days, I run Mitas E-10s or TKCs, so these just sit in my garage unused. Any UK FFs (or folks from overseas prepared to pay whatever shipping actually costs on what is quite a heavy item) wanting to buy mine can send me a PM with serious offers, although I'm in no rush to sell them.
Caution; if you are cutting off 'spare' links off the end, make sure you only do so after fitting them on a new tyre and even then, leave one more link than you need (in case you ever want to go with different tyres). If you size them on worn tyres, you'll end up with them being too small to fit new tyres. Ask me how I know.
As an aside, they fit perfectly (along with the tensioning springs) in the touratech bash plate toolbox. It's a great place to carry them; low down, unlike tools it doesn't matter if they get wet there, etc. Chains "settle in transit" like cereal; if at first they seem to big to0 fit in, put the larger of the two in and then ride the bike half a mile, then stick the other in, it will then fit.