^^ And if doing those couple of things doesn't fix your problem, if could be worth checking the bolt on the front drive pulley before you go too far!! :shocked:
Other things that might/could be causing you to feel more vibrations thru the pegs.... different road surfaces; worn front 'A' arm bushes; front wheels need balancing; need a wheel alignment; maybe even a pebble wedged into the drive belt somewhere.... but I'd still be starting with checking/adjusting belt tension & then checking the mounting bolts for the pegs first!
Hope you find & sort it easily! Good Luck :thumbup: