First let me say that I love my SBP"s jackshaft.I'm not Knocking or bashing them or there jackshaft! Jim has been great with anything I've needed.My question is anyone having problems with their front freewheel bearing. my first one lasted about 20miles and Jim sent me a replacement and this one lasted about 5 miles? I guess i should have ordered the heavy duty kit. Whats the verdict on the heavy duty bearing? I want to make sure it going to hold up. Cause my jackshaft is "dead in the water" without a front bearing. Again, I'm not trying to discourage anyone from the jackshafts. I personally love mine and will never go back to a single speed bike. I just think maybe everyone should maybe just go ahead and buy the heavy duty kit. Thanks.