I don't worry much about what people think of seeing my big frame on a bike. I'm too busy avoiding cars and pot-holes while enjoying the fresh air. My only pet peeve is people who assume I'm slow. The motorists who turn in front of me forcing me to slam the breaks or the fair weather cyclists who stream in front of me at a red light only to pass them a couple hundred meters later. After 3 years of regular commuting I can keep up with the average bicycle traffic no problem. Despite my size my cardiae-vascular is in tiptop shape.
As a Clyde myself I can certainly say I've had mechanical problems because of weight load. I ride a mountain bike frame since they're usually tougher. Most common issue is the rear wheel failing. At least every year or so I have to get the rear wheel repaired or replaced. The first time I walked into the shop with a busted rear axle I felt embarrassed. But I don't worry about it anymore. Now, I just chalk it up to wear and tear since I cycle almost year round. Just this week on my first winter commute when I got home I found busted spokes.
As one mechanic once told me: "you ride the sh*t out of your bike!" And I do and I'm proud of it.
