Nowhere near worn out Rainman, and that includes a trip to Spain. But I will admit I'm not a quick rider (on the road) can't see the point of losing my licence. But the point is my bikes don't turn left automatically
It's frighteningly easy to take the Pirelli Scoprion Trail's right to the edge, and that's not an indicator of you being an excellent rider. I was warned (by Andy, on here) that when I changed my first rear Scorpion for the Bridgestone T30 Evo that I should definitely change the front at the same time as the increased angle afforded by the T30's could see you riding off the edge of the front Scorpion with ease - the consequences of which we won't talk about. My Scorpion's were completely worn right to the edge, but on my T30 Evo's I've got a 15mm chicken strip on either side even though the data from my phone app shows that I've been leaning, on average, 5 degrees further on the T30 Evo's. That's not much further, but shows the limitations of the Scorpion's pretty well. If I rode with the Scorpion's the same way as I currently ride with T30's I'm quite certain I wouldn't have managed to get to 16.5K miles without things going titsup. I don't know why they put such crap tyres on a bike that can easily exceed have their performance envelop exceeded. BMW don't do it on the S1000XR and hardly anyone is going to be daft enough take a non-Enduro Multistrada with 17" wheels off-road.
I'm not disputing that, in much the same way as you can't dispute that there might be something in your riding style which subconsciously counteracts the effects of road camber ... which is just as likely. Are you going to tell me that your car isn't affected too, and just runs straight ahead without the very occasional correction to the right?
I was more making the point that the profile has worn quite evenly, rather than I’m the 2nd coming of Rossi
Try riding on the opposite side of the road, where you would normally compared to the verge and see if it pulls right. On sports bikes especially, you grip the tank with your knees if you let go of the bars and heave yourself up. That then means you are keeping the bike straight with your body. On a multi, you can simply lift them and knees arent doing the job. May be that there is a bias somehow, which is exaggerated by the camber. Or that the left pannier is larger and carries more than the right pannier, as the exhaust means less volume.
I wouldn't mind betting that even if he did ride on the wrong side of the road it'll still pull to the left.
I suspect that many folk put more and heavier goods in the left pannier, because it is larger, and less stuff in the smaller right one. This is a mistake. It is better to put heavier things in the right side, and lighter items (or nothing) in the left, as I have suggested.
Whilst I would agree with everything you mention, I would also add that the positioning of loads relative to the centre of gravity of the whole motorcycle is every bit as important. Weight that is added further away from the centre-line and higher above the centre of gravity will have a much greater effect than weight positioned closer to the centre of gravity. The Multistrada's panniers are not exactly spacious on either side, certainly not when you compare them to the offerings across the BMW range, or after market Givi pannier solutions. Also, Multistrada's panniers don't exactly stick out miles and they're not particularly deep. I'm not saying that the effect of uneven loading would be negligible, but it certainly wouldn't be as pronounced as it would be on some bikes. Recently I had a need to carry a single large-ish box-file which wouldn't fit in the right pannier due to the odd shape. It had to go in the left and I couldn't split the load across the two panniers. I was dreading riding with the unbalanced load but in actual fact it's wasn't terrible at all. Admittedly, I didn't remove my hands from the handle bars at any point ... largely because I'm not a moron that's inclined to do such a thing on a blatantly imbalanced machine.
The chain is likely offset by a faster rotating mass on the opposite side of the engine. Also, the chain is a rotating mass and therefore the faster it runs the more gyroscopic stability it's mass will provide. All these things are taken into consideration in design - same reason exhaust runs on the opposite side of the swingarm, (although the swingarm dictates position of the exhaust somewhat anyway). Individually they don't make a whole lot of difference, but collectively they add up. Besides, if it's close enough to the centre line of the bike you can get away with quite a lot, and the chain is within about 4" of the centre line - I doubt very much that it's going to cause much of a difference or the rest of the world would be complaining about being dragged toward the central reservation on motorways.
What has all this got to do with the OP's question about his bike wandering to the left with or without his panniers, which I still think is down to his posture on the bike
I have this issue on my DVT, regardless of side of the road. I had the dealer put on PR4's when I bought it and it occurred when new and still happens several thousand miles later, it may be the tyres I suppose as I haven't tried anything different. Not sure if I agree with the tyre balancing argument as any imbalanced tyres I've ever had have given the rumble and judder not pulling to one side. Tracking might be off I suppose. I can't for the life of me remember if I tried to sit back with my hands off the bars without the cruise on, if its not there when cruise is off then maybe its some kind of torque steer from the engine?
You won't get torque steer from any transverse engine layout. The reciprocating masses run forwards or backwards (or in the case of the V4 Panigale, both simultaneously), not side to side. A longitudinal mounted engine (eg, All BMW boxers, Moto Guzzi and various Honda's from a bygone era - ST1100, CX500, etc) can have a very pronounced torque influence from the motor. Just sit on any BMW boxer and at a standstill just blip the throttle - it's very disconcerting if you're not expecting it, but does it translate into torque steer in the same way the differential gearbox on a front-wheel drive car does? I don't know.
Interesting, and I think I can see what you're driving it. I've never tried using the app in realtime. The trouble is that I believe the IMU would use a datum point defined by gravity or some other global constant. Therefore it would not take into account the angle of the bike relative to the road surface. If we we're trying to identify whether the bike's geometry was out, or if we were experiencing the affects of road camber, then I don't think that it would be useful data, and it still wouldn't tell you if your riding position was doing anything to effect it. Much easier to take it to a dealer and get the geometry checked. Plenty have the laser tech to do it these days. My car has to have it done as part of it's routine servicing.
With a single sided swing arm and central eccentric adjustment I can't believe there would be an alignment issue. Unless all those bikes have had a crash and bent the same bits at some time. Unlikely.
Well exactly, which if you just took it to a dealer it would rule that out and leave you with one less thing to consider and possibly looking at yourself more than the bike.
Ok, I did a couple of quick tests today.... Only happens with the engine under load, same bit of road same speed, without cruise on bike tracks straight and true with cruise on it pulls to the side.
Sorry tater, but that doesn't make sense. If you haven't got cruise control on it means you have to have at least your right hand on the handlebar surely ?
