Instruct: Classify Amazon reviews into positive or negative sentiment
Query: DANGEROUS!!! : Do NOT buy these!

We bought these for my son and within a minute of riding his bike the "tire" on one of them split in two and fell off... as did my son. Thankfully he wasn't going too fast.I have only heard good things about Bell Products, so I assumed it was just that we got unlucky and so we bought a replacement set. This time the tire came off the wheel altogether and I am very, very thankful that I was running alongside my son as he raced down a hill so I could catch him before he face planted on the asphalt. These are flawed and DANGEROUS. I do not recommend that anyone buy these!!!!!!!I will be contacted Bell about them when their office opens on Monday. If I could give this review a ZERO I would.