[Flip]

When I first bought my race bike it had a composite tank fitted and despite it being coated with some type of sealant on the inside it still suffered bubbling and expansion.

At the time I didn't even think to drain the tank between races and since then I have had an ally one made so the problem has gone away for me there but the composite one didn't regain it's former shape after draining and leaving it and I don't really see how the plastic ones fitted to many newer bikes would either.

I honestly cannot believe the manufactures are letting this go with the fuel companies or that it wasn't researched more thoroughly in order to have prevented this as it is only set to get worse as the percentage of Ethanol in fuels is set to increase over the coming years.

In addition to this there is also the problem of it affecting the mixture of carburated engines which I presume the ECU of fuel injected motors can compensate for at least.

If it were me (and especially if I had bought the bike brand new like you) I would be pestering Ducati constantly in the hope that they eventually get fed up and give you a new tank to shut you up- a full service history etc. is a load of boll*cks excuse not to help although of course long term even if they did replace the tank it will likely happen again unless Ethanol is no longer added to fuels.