il cambio è uno sram rival con la compact davanti, il forcellino dovrebbe essere questo:
https://it.aliexpress.com/item/MTB-Strada-di-Montagna-Della-Bici-Della-Bicicletta-Deragliatore-Posteriore-Gancio-di-Estensione-Extender-Cornice-Gear/32893307679.html?spm=a2g0y.search0104.3.24.7f5432f5z5SnwJ&transAbTest=ae803_4&ws_ab_test=searchweb0_0,searchweb201602_5_10065_10068_10890_318_319_10546_10548_317_10696_450_10084_10083_10618_452_535_534_10304_10307_533_10820_532_5023915_204_10843_10059_10884_323_325_10887_100031_320_321_322_5727715_10103_448_449_5727815,searchweb201603_2,ppcSwitch_0&algo_pvid=79b95b1b-4d59-4133-9069-185375de1a75&algo_expid=79b95b1b-4d59-4133-9069-185375de1a75-2
https://it.aliexpress.com/item/MTB-Strada-di-Montagna-Della-Bici-Della-Bicicletta-Deragliatore-Posteriore-Gancio-di-Estensione-Extender-Cornice-Gear/32893307679.html?spm=a2g0y.search0104.3.24.7f5432f5z5SnwJ&transAbTest=ae803_4&ws_ab_test=searchweb0_0,searchweb201602_5_10065_10068_10890_318_319_10546_10548_317_10696_450_10084_10083_10618_452_535_534_10304_10307_533_10820_532_5023915_204_10843_10059_10884_323_325_10887_100031_320_321_322_5727715_10103_448_449_5727815,searchweb201603_2,ppcSwitch_0&algo_pvid=79b95b1b-4d59-4133-9069-185375de1a75&algo_expid=79b95b1b-4d59-4133-9069-185375de1a75-2