I think most bike sites can't find the balance between having to sell lifestyle and stating facts about the products. To me it seems like most of the time its the lifestyle that wins and information and site usability gets lost in funky design and navigation.
I acutally think Kona has done a great job over the years with their web design. Not super flashy but they still squeeze a good amount of lifestyle into the site, its easy to navigate and find fact about the bike. Except for real weight which seems like an impossible fact for bike companies to find for some reason.
What is good web design, all around good design, this is my opinion so don't pay it much mind.
We as a society are a very visually oriented culture. You have to have the latest bling, that outfit is hot, must have the perfect body.
So going on that thought process a website must be very aesthetically pleasing.
But on another note we are the "now" generation. We want our information pretty much served to us and we want it fast and even that isn't fast enough. So on top of the aesthetically pleasing rule add in a good dose of usability, legibility, and speed of proper information presentation.
So a truly good website is one that is pretty and logical. Easy - short answer.
Not a site issue, but a company issue. I price smashed a set of bars at Cambria, prefering to deal with a company I have knowledge of and a good track record with. It goes through, and through my bank, and three days later I get a snotty email from some prick there shooting it down. WTF?
They had better refund my $$ quickly, and I will think twice before ever dealing with them again...