Thats I why I said the way it's bent Paul,remember this is what I do for a living. A bent rim will definately bubble balance and if not bent too badly will spin balance then showing up as a shake or vibration at only higher speeds. Normally if spin balanced it will take an out of the ordinary amount of weight to get it to balance thus indicating a need to check the rim. Trouble is it isn't always a bent rim sometimes its a tire made under low quality control so the mechanic balancing it may have been lazy and not bothered to check for a bent rim as long as it balanced.

LOL I just typed all that then reread your post and you are correct about the 10 to 15 mph window I misread it as after 10mph. The axles/wheel bearings are a good thought and if that is the cause fix it now since for a wheel bearing to cause a shake like that they must be really bad.

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