About 7 months ago I had a new bottom bracket and chain ring fitted to my bike by a reputable bike shop. I cycle 7 miles each way to work and do spend alot of time off the seat in top gear going fast up hills and I am over 18 Stone in weight. The other day I was cycling to work and noticed the chain ring is wobbling, it does this more when going up hill. But normally when my bopttom bracket goes, when I get off the bike and shake it, it feels loose. This time if I give it a shake it feels like it is still tight but when I ride the bike it looks and feels loose. Can anyone tell me what this problem is?