DoubleDeere
Bronze Member
V belt vibration is normal. A smaller V belt will roll inside the grooves as it will walk inside the larger diameter pulley.
The same thing occurs with using am SAE belt on metric pulleys(been there done that with my JD JUNK snow blower-I can buy 6 V belts for the price of one JD driven V belt for my 44 inch snow thrower JUNK.
The Teagle Flail Mower uses a one piece 4-groove V belt for its high horsepower flail mowers and a very large coil spring to maintain snubber pulley tension.
I did not recommend a narrower profile belt.