High speed front wheel jumping

I just had a new inner tube put in my front tire. When I took her on the highway yesterday, the front wheel began hopping up and down at around 75-85mph. It doesn't seem that a new innertube would mess the balance that much, and the guy I took it to usually does a fantastic job.
My question- could I have possibly done something wrong installing the front wheel? Could it really be out of balance with a new inner tube in the old tire? Please help, as I want desperately to drive the socks out of her

check to see if the tire is beaded up all round the rim you will see a line in the side wall off the tire to show that it is even all the way around.

Was the tire spin balanced? Some tires have a colored spot where the valve stem is supposed to go for good balance.

Wonder if the guy put too large a tube in, and it is partially wadded up in one spot. Did you watch while he worked? Surely he didn't pinch the tube and then put some kind if liquid such as fix a flat to repair the small hole. Forgive me, my mind is running amuck.

I have had tires that were out of balance by about 1 ounce, and it was almost unnoticeable. After being balanced it was glassy smooth at say 75 MPH. I would think we are talking like 3 ounces or more out of balance to cause what you are experiencing. Must be something significant.

depending on what tire pressure you are used to it may/will make a big difference.....check that it is at least 32--and not more than 36....imo...others may not agree.....i put a new front on and dropped from my normal 36 to 33 and a pogo went away...just like that....

Thanks for all the replies. I did not watch as he put the tube in. I did hear them say that they were short some sizes, but its not like him to lie about such things. I actually have a great MC shop named Totegoat. Honest people, 30 years + history here. Very small shop that relies on its reputation. I wonder if he did not balance it though, because he did it in a hurry- they were crazy busy. Well, I'm going to take it in asap and have him recheck his work. In any case, it wasn't bouncing with the old tire at all. It was silky all the way to 115.

Forgot to mention, turning now seems very unreliable. I was zooming down a mountain Colorado road full of hairpin twisties when I found that out. It felt like I was going airborne down a few curves. Very strange senstion:woohoo:

trianglelaguna wrote:

depending on what tire pressure you are used to it may/will make a big difference.....check that it is at least 32--and not more than 36....imo...others may not agree.....i put a new front on and dropped from my normal 36 to 33 and a pogo went away...just like that....

right before your caliper bolt fell out! :S :laugh: