If you're in Michigan, you've got winter salt corrosion. This led to corrosion of the caps on the bars. It only took 3 months. The tires were flat and took pliers to remove three caps and on the fourth tire I had to replace the stem which cost me more than the caps. I had a set of aluminum Harley-Davidson caps that I lost which prompted me to buy them. I've never had a problem with them!