I have a slightly older bike with, I believe, a 7-speed Shimano RX100 groupset. I would like to use this with a direct drive smart-trainer. Can I install an 8-speed cassette easily? :
Vintage Shimano 105 RD-5900 & RX100 FD553 Road Bike Derailleurs Fast Shipping | SidelineSwap
Shimano RX100 Rear Derailleur | With Campagnolo Super Record… | Flickr