Just wanted to enter the forum and add my experience.
Bought a used GS 310 ADVENTURE - just over 2000 miles from new, great tidy condition. Bike was delivered to me from the BMW dealership. UK based.
It arrived and I was excited. Delivery driver left and I went to start it. Nothing. Wouldn't start! Called the dealership (this was supposed to be fully serviced as was sold by the dealer. They said they will return to collect it and take it back to the dealership. I said no I will charge it and persevere! Probably a flat battery. Anyway I managed to get it started after quite a few attempts with no charge.
Got around the first bend into changing up to second. Wouldn't shift. Literally wouldn't shift from first to second gear. Weird. Thought the gearbox has a fault.
Called BMW the second time in the same day. They asked me to persevere for a few days and I said fine. Oddly the battery issue and the shifting rectified itself. Never had anything like this and I have been riding many many years. Tonnes of bikes.
Had the bike for a few months and had intermittent starting issues but I charged the battery on a good trickle charger and it seemed okay. Albeit had these occasional start issues (summer months). Finally after half a year - winter (keeping it trickle charged and using every other day including winter) had to get roadside assistance. It broke down on me. Got from house to destination with no issue but wouldn't start after a good run. Weird.
Roadside tech tested and said the battery is faulty. Needs replacing. He didn't take the bike (BMW told me they would take it if required). He got it started and I had to ride home.
So I reported this to them and also this weird issue with the shifting which would pop up once/twice a month with the shift not letting me change gear.
They have had the bike now for 19/20 days and still no ETA to return it. They wouldn't ship me a battery to change myself and wanted to try and charge me £300 for the battery (£160 approx.) and £70 each way to collect/return (even though they had been to the bike once with the correct van they could have taken it away. I caused a major fuss and said no way are you charging me for this and they did collect it and offer to do the work for 'free' which is hilarious as its still in the warranty they sold with it as I reminded them. Not impressed by this response whatsoever.
So now they tell me the cush drive rubbers are shot. I googled this and found others have had this issue. My other issues they found include something on the wiring loom needed replacing, cush drive rubbers, the chain is going rusty amazingly fast, like nothing I have ever seen - even when lubed up well (piss poor quality parts basically!). They won't swap the battery which I have read loads about being rubbish (OEM) for anything better. I know think I know why the first/one previous owner traded it in.
My experience seems to be that the parts are evidently very cheap and poor quality. Remember it does have a BMW badge on it and as I said to them this is far from BMW reliability. If I have parts failing like this at less than 3000 miles it doesn't lead me to think others will last that long. Not confidence inspiring at all.
My main 'concern' is they are explaining the cush drive rubbers would lock the gears from being able to shift completely if faulty. I think that sounds really 'weird' and that's my main question to everyone. I have had so many bikes and in over 250,000miles of riding I have done loads of my own mech work and NEVER had cush drive rubbers even need replacing let alone even heard of having to do it at such low mileage. Also does it sound right what they are telling me that the weird gear box issue with it completely not shifting from 1st to 2nd - like the engine is seized (it's not but that's the same kind of feeling - total locking of the gear) down to these rubbers. Sounds like BS to me. If the rubbers have failed surely the issue wouldn;t come and go as it has. Feels like a gearbox issue to me. Don't see how these 'dampeners' will literally lock the shifter completely once/twice a month and then free the gears up as normal then do it again later. casual riding. This is not off-roading either. Feel like they are fobbing me off.
Thanks all - great forum