Hello Douglas,
These are reasonably well made, but they're UK-based, so value may depend on your postage costs:
https://www.ebay.co.uk/itm/BMW-K1200S-Carbon-Fibre-Fender-Extender-ALL-YEARS/143198486081On the bike:
https://eurokclub.bike/index.php?topic=1198.msg13235#msg13235A few things to note - whether you buy this one or another extender:
- as well as double-sided sticky tape to tick it in place initially, you will have to drill the front mudguard & bolt it in place. This one comes with the nuts & bolts.
- you may need to trim the edges. They're too close to the tyre sidewall for my liking. It's easily fixed though.
https://eurokclub.bike/index.php?topic=2883.msg34248#msg34248- once fitted, the elongated mudguard will flex slightly on bumps & just touch the tyre, and cause a noise / 'chirrup'. I've run about 20k miles with that, and although it's annoying, there no damage or danger to the tyre, but the very bottom of the mudguard eventually rubs away. Then it stops :-)
If you want perfection, then pair it with a carbon mudguard. The carbon mudguard is much stiffer than the standard plastic one, and the extender can't 'chirrup' - silence + better protection. But that's a hell of an expensive fix unless you pick up a used carbon mudguard cheap.
While you're thinking about that, here's a rear extender. Looks small, but stops quite a bit of muck flying around:
https://www.bmw-motorrad-bohling.com/uk/bmw-rear-fender-enlarger-for-k1300r-and-k1200r.html (requires a small amount of cutting to fit a Motorsport as I found out. 10 mins to cut and 10 to fit) Use the part number 71 60 7 697 281 to find it in the USA.
Or, it seems a bit cheaper here, in the UK at least:
http://www.douglasparkparts.co.uk/product/Rear_spray_guard_71-60-7-697-281-K1300RIgnore the R description for the rear extender - it fits an S as well.
Again, a rear carbon fender (Ilmberger, ideally) will give you the perfect pairing, but again, you'll need to get the wallet out.