i have a 2007 cbr 1000 with 9600 miles. when i get to about 40 or 50mph theres a front end vibration it almost feels like its a flat spot in the tire but the tires are brand new. also i tightened the chain a few days ago and my friend was putting chain lube on it and i noticed that when i let the clutch out it looks like the sprocket turns a little before the wheel actually does is that normal. thanks

 

Even though the tires are brand new, you may want to inspect them. Sometimes there are defects even with brand new tires, or the installation wasn't done correctly and it can damage the structure of the tire. Run your hand all along the tread as well around the sidewalls. Check for any dips or raised portions, just anything that doesn't look right.

Also, its possible the tires weren't ballanced correctly. If you have an out of ballance tire, there will be certain mph that it will be felt. It also won't be noticable in all mph, only at certain speeds. I'd check with whoever put them on and make sure they were ballanced. Also check your tire pressure to make sure its where it is suppose to be. Also make sure it wasn't put on backwards. it happens from time to time. Check the arrow on the sidewall to make sure the rotation is correct.

As for the rear, these bikes use a cush drive system. The sprocket is not mounted directly to the wheel, there are quite a few wedge shaped, hard rubber pieces that wedged between the wheel and the sprocket plate, that isolate the driveline harshness. If you can imagine a motor shaft coupler, its basically the same thing.This also protects the transmission and the rest of the driveline from anything the wheel may encounter. So, you may notice some movement before the wheel moves, but there shouldn't be a lot.

 

thanks for your help. i went for a ride today i didnt check the tire becuase i just looked at your reply now but when i hit my front breaks i can feel the vibration to could it be a warped rotor

 

Its very possible a rotor is warped. But remember as you hit the brakes, your transfering weight to the front of the bike, where if the tire is bad, it can be more noticable during braking.

Since it sounds like you just had the tires changed. I'd inspect everything to make sure all was put back the way it was suppose to be. The only real problem here is most of the things you should check require the front end of the bike to lifted of the ground. Most people don't have front bike lifts or ways to do this.