I had a broken seatstay repaired on a Cervelo frame about 15 years ago. I was always afraid to ride it outside afterwards (going 40+ mph downhills) so I stuck it on my indoor trainer. I have been riding that bike indoors for the last 15 years with no problems. I think I made the right decision though. My safety and piece of mind was more important than the money I spent on a new outdoor bike.