There's a couple of things you can check. One is contact information. If you have problems, are you limited to email contact? A legitimate store will generally have a street address, phone numbers, etc. (Edit: In this case, I don't see one single thing that even indicates what country they're in, and that would obviously have a large impact on shipping costs, if they actually shipped anything.)

Secondly, presuming it shows where they are located, check the bike lines they offer, then look on those manufacturers' websites and see if this dealer is listed as one of their dealers. If they are selling brand X in Country Y, but Brand X doesn't list them as a dealer, that's a pretty good sign that they're not a legitimate business.

I see their main email contact is a hotmail account, which is not very reassuring!