Hi all,

I'm leading an effort to choose a durable, weatherproof bike for my university's Bike Share program. Our current bikes are fat-tire cruisers designed for beachside rental fleets and do the job well, but we're looking for something less clunky to encourage students to ride around town, not just around campus. We're looking towards Bikes Direct-ish Dutch-style commuters with hybrid-width tires. We also have access to a J&B account for parts and accessories. I have a few questions for the community:

• As the bikes will be stored outdoors near the beach, resistance to rust is a priority. Are steel frames okay, or is aluminum a must? Are some aluminum alloys more rust-resistant than others? What differentiates high-tensile steel from chrome-moly?
• What makes a chain weatherproof? Would a complete chain case make up for a "standard" chain kept outside near the beach?
• What distinguishes strong wheels from weak ones? Spoke count and manufacturer are a given, but are there other ways to distinguish the good from the bad (type of alloy, etc)?
• Any other suggestions or recommended products?

Aluminium frames are standard on all mid-priced factory frames, steel is a specialist item or very low end. It is a good material to leave out all day.
For forks you want steel, either hi tensile or better chromoly.
36 spoke wheels are the strongest you can commonly find, they should be trouble-free.
There is a low maintenance alternative to chains, Gates carbon drive. You need a frame where the rear triangle splits apart and you can only run hub gears, not derailleur gears, but 3/5/7speed hub gears are a good, low maintenance choice.
Use hub brakes , hub dynamo for lighting and fit the best protected tyres such as Schwalbe Marathon Plus.