What make and model shift lever or STI are you using? Although I'm not sure that in 9 speed applications there is any difference between mountain or road bike components. If by some odd chance you have a 11 speed road shifter or a 10 speed Tiagra 4700, that would be a issue shifting on that 9 speed cassette... for several reasons
Last edited by Iride01; 04-14-24 at 09:31 AM.