The OE handguards have been doing my head in for some time, personally for weather protection, they're good, for anything else, you may as well wrap a loaf of bread round the bar.
So I decided to get some Acerbis ones, not wanting to pay Touratech tax and shipping i just bought the Rally Pro Guards (the ones with the aluminium inner) and the 'variable' mounting kit, together with some spoilers, about 65-70 GBP.
Here's what i did...
Firstly, i have OE bars, which have a wedge of threaded steel welded into the end of the bars, so the expanding bolt you get with the mounting kit is out straight away.
The gaurds will not stretch to the ends of the lengthy bar weights, but they will go a little further out that the handlebar, solution, chop of the existing bar weight so it measure 21mm in length. Prime and paint the exposed metal.
This also means that you have to file away a bit of the pastic on the gaurds so that the outer end of the cut down bar weight makes a tidy mate with it.
The OE bolt for the bar end is M6, so i stick with that and just got a longer bolt, i think it was about 70mm.
The bolts you get with the mounting kit are M8 countersunk. Drill out the top of this bolt with a 6mm drill and chop it of, now you have a perfect countersunk washer for the M6 bolt.
To mount it you need to loosed of both of the clusters of controls so they move about, this allows access to the bolts for the handguards, which are mounted below the cross beam.
With a little bit of fettling they fit fine, with no interference to the clutch of break lever, its close, but not touching.
Remember locking compound on the M6 bolt, and hey presto, substantially stronger handguards, and personally i think they look pretty nifty too...