Just this weekend I got my first bike - a Honda XL750 Transalp. Winter is coming where I live, so when I saw a blue sky, dry roads and temperatures just over 0, I thought I could have a little ride. But that wasn't the stupid, even though I forgot the keys after being completely suited up with thin jogging gloves and winter gloves.
There wasn't any stupid during the ride, although I forgot the keys again after putting on the two pairs of gloves after a little break. Or that I kept hitting the hazard lights by accident, or the high beams.
The stupid was when I got back and rolled into the driveway. I wanted to slowly roll in and park in front of the wall of the garage. Had the clutch pulled and apparently twisted my wrist to get my thumb on the kill switch. The motor revved up so loud it scared the whole family out the house and onto the porch, where they witnessed me rolling towards the wall, bumping into it because I was so startled I didn't remember to apply the brake and me falling very, very slowly and gently (almost with a certain grace, I hope) to the side.
As far as I could see, there's only a few scratches on the bar end and the peg. Whew! But, I was told I bumped hard enough that the rear wheel lifted into the air! Hope that the fork and frame are ok!
Was a real downer after the nice ride, but I guess it's true what I heard, that all riders fall at least once!
I think your first doing a stupid is buying a 750 for your first bike!
This is a predominantly American Men's thing, as far as I can tell. Many get the biggest bike they can, fail to learn to control it, and then go around chest thumping.
Meanwhile the best rider I know, a professional test rider, spends his weekends teaching Moto Gymkhana on a 125.
A 750cc isn't that big of a bike... I started riding at 6 years old with a 50cc dirt bike but the bike I have now (and the last one I've ridden) is a 2300cc Triumph.
My first street bike was 550cc and my favorite street bike was a 1997 750cc Suzuki Intruder but it never felt like a big bike at all ... Certainly not compared to this Rocket 3.
You didn't go for a Boss Hoss? That Rocket must feel tiny.
Part of the reason bigger engines are desirable in the US is because to get anywhere other than local riding you're going to be on quite a bit of long straight highway at high speeds. I can drive for 15 hours straight at highway speeds and still not leave my state.
A 250 will be absolutely tapped out to the point of being unsafe because you have no reserve power. And that seems unnecessarily hard on the vehicle.
A 500 will typically be usable but uncomfortable because it'll still be high in the rev range and vibrating.
On the longer stretches doing maybe around 75mph I even find myself wishing my 800GS could chill at some lower RPMs (currently around 5k maybe a bit more at those speeds), whereas my brothers 1400 with 2/3 the horsepower of mine just chugs along at those speeds (no tach but I think about 3200rpm is what I calculated and that sounds about right). When I pass him he says mine sounds like a mosquito.
Except that OP is in the UK.
While you might want to go in straight lines most of the time being able to handle corners first is a good idea, plus things like emergency brake and swerve techniques to avoid accidents ... the European test only checks if you can emergency brake from 30mph, stopping from 75 with enough technique to feel like your eyeballs are being sucked out of your skull takes practice.
Hell, I remember one American on Reddit who swore up and down that you shouldn't use the front brake to emergency stop - for people who really love motorbikes extra training is a must, and that starts with a small bike you can drop a lot while learning how to use the whole tire and how to handle a bike when the front wheel locks, etc.
Edit: as for your BMW, why not just add a tooth to front sprocket?