The vibration problem in the Hero HF Deluxe can be attributed to several factors. One common issue is related to the engine, where vibrations are felt particularly at higher RPMs. This could be due to improper engine mounting, loose bolts, or issues with the engine itself. Users have reported that checking and tightening all bolts, including engine mounts, can sometimes alleviate the problem. Additionally, wheel imbalance or "back wheel bubbling" can cause significant vibrations, especially at high speeds. It is also advisable to check the fuel quality, as old or low-quality fuel can exacerbate the vibration issue. For a definitive diagnosis and repair, it is recommended to consult an authorized service center, as they can perform a thorough inspection and necessary adjustments or repairs.