Originally Posted by mass-klr
Are you setting up once or packing up and moving every morning?
Most suggest getting a size one person bigger than you'll need - meaning a 2 person for a solo camper. This lets you stick all your stuff in the tent with you if need be.
As for weatherproof - backpacking tents are the most packable, usually best weatherproofing, and will be the most expensive. Heavier will be cheaper, and for moto-camping thats perfectly fine. The difference between a 5lb and a 7lb tent won't affect your bike at all but your wallet will feel the difference. One thing to look at is pole length... this can be the deciding factor in how you can pack the thing. I'd also suggest staying away from any fiberglass poles.