There are some big differences. The fastest I'd ever go on a road bike (around 50) is about the slowest I go on a street bike. Wearing the gear on motorcycle doesn't cost me anything except a little discomfort. When riding a bicycle I'd not be able to make it 5 miles little lone 20 to 100mi wearing leathers on a road bike. I've seen some nasty bike crashes though where i'm sure people wish they where wearing gear. At the end of the day I don't wear protection on bicycles because it doesn't exist... I'd love to see some kevlar stretch bib shorts and jerseys and better gloves.