I would think that you are talking about the rear wheel, it has two chain tension regulators, the first thing you have to observe is that the wheel has been centered on the rear oscillating fork, the centering is done through both regulators. The shock absorbers could be expired, overload them with the regulator that they have on the bottom, but you comment that the fault appeared after patching it, so first perform the task that I told you and if you ever rub on the fender while a person was sitting just there adjust the shock absorber, this adjustment is a test before replacing both shock absorbers.