recommend me a bottle gage and a bottle with a lid [cover]- needs to be a good tight fit – don’t want the bottle falling out mid flight

Camelbak bottle with mud cover?

Going to need more cover than that – bottle cage is on the bottom of the down tube

Halfords do Elite bottles for about £4.

Tacx Tao cages are a soft aluminium that can be shaped by hand to ensure a good fit. If you’re really worried, just tie a strap around the bottle and cage.

Elite looks good thanks

Going to need more cover than that – bottle cage is on the bottom of the down tube

Depends what you’re trying to achieve. The Camelbak mud cap does a great job of keeping mud out of the bite valve; under the down tube the outside of the bottle is going to end up splattered whatever you do.

Decathlon do some bog standard bottles with a big clear plastic lid that clicks in place. Kept my lad mud and germ free till he wanted a camelbak lookalike