A few days ago i thought the bike was dirty and needed a winter clean after being stood in the garage for 2 months, but when i set to with the cleaning stuff i noticed that it was little growths of mould scattered around the frame and exhaust (basically all the metal bits). They wiped of easily, but they were mainly in the areas that were wet through condensation. Will this cause any damage or corrosion? My bike lives in a draughty garage btw.
Looked at mine yesterday, also little bits of mould on the tank. Light rusting of the rollers on my eight month old chain too. Now washed, rinsed and dried plus a liberal application of GT85 to the chain.
My garage is similar to yours but i use a lot of ACF-50 which in my opinion is the best long term storage liquid for your bike, i also use a cover but have a very small tube heater under the cover on a timer, this provides a decent amount of background heat, i have never had any issues.
You can get things called heat traces, they are used in industry for small scale background heat i.e. wrapped around a water pipe to stop it freezing. They are low wattage so quite cheap to run. 4M FROST PROTECTION KIT (HEAT TRACING PIPE PROTECTION) | eBay Mike.