[ecomodded]

Check the rear rims for damage as well, and for out of round tires or bulges inspect them closely or have a friend look them over, jack each tire off the ground and spin with intent on catching a bump or lump or bulge.

I agree you should take it back to the repair shop, be friendly they missed it but ask them to recheck it as your not happy with the repair job -

I have pointed out a bad tire to a few people with a shimmy, although those types of a shimmy have happened even at low speed