Anyone able to recommend a jacket that will go over 1 piece leathers and be waterproof? Also what size did you need as compared to your usual sizing so it will fit but not flap about too much?
I reckon you'll need a one piece suit. I bought a Spada one-piece for a one day training course which was forecast to be wet. I don't generally ride in the rain so I didn't want to spend too much. It cost £60, I wore it all day and it let not a single drop of water through. You do blow up like a Michelin man but it doesn't flap, its comfortable, light, easy to get on and off over boots and it packs away neatly into a sewn-in stuff bag. You can get heavier suits which don't blow up so much but they'll be bulkier to carry and cost a lot more. The size is correct if the legs and sleeves are the right length and you have enough room across the shoulders. It will be loose cut everywhere else but its meant to be. If you go down a size to reduce bagginess while you're looking in the mirror you'll regret it when you get on the bike.
I have an oversuit but it just feels massive - blows up just like you say! Am more after a jacket as legs stay protected by fairings to some extent and want something carryable
I have one of these Alpinestars Eclipse Tech Over Jacket - Demon Tweeks .....extra large is a perfect fit over a 54 sized suit inc hump...... waterproof, seals at the wrists etc etc and it doesn't flap about!