I don't know what kind of speeds you run at on whatever you call your limited access highways in the UK, here in the southwest US the speed limit is 75 mph .
At that speed, you don't have too much more power available if you needed it, and that's with one rider .
As stated, you will wear out long before the bike will at high speeds .
As far mods are concerned, I'm a 'stock bike' kind of person, after having my '81 going on 31 years and reading experiences of other owners here on this site for the last 10 years or here's my list of things to do .
Replace the rubber lines with braided stainless lines, if the brake pads are in need of replacement, don't use OEM, I've used EBC pads and they are far superior to OEM parts .
When you replace the rotors when they need it, EBC has semi floating steel rotors, these with the EBC pads make remarkable difference in wet braking over the OEM parts .
Gaiters on the forks, they look odd at first, but after awhile they look like they belong there .
Replace the Hall Effect sensor in the 'bean can' along with the advance springs .
Replace the ignition coil with a reliable aftermarket dual output coil, here in North America, the Dyna "brown' coil is a common replacement, don't know what's available locally for you .
Get a good brand rebuildable shock absorbers .
I do alot of night riding, I've upgraded the tail light/brake light with an LED unit .
I've also added side 'running' LED lights at the rear in place of the red reflectors .
I installed a set of PIAA 40 driving lights, but I doubt they would be tolerated in your area by law enforcement .
Nobody can say they don't see me now, they have saved my 'hide' more than once since they were put on .
I added 4 way hazard flashers with an OEM kit from BMW, it's not made for the '81 model year and later bikes, it can be made to work, but if you aren't electrically inclined, I wouldn't recommend it, there are several aftermarket versions available .
