RX100 7-speed w/ 8-speed cassette?
I'm trying to kludge a commuter together from the remains of an early-90s Miyata 914 and some spare parts. I've got the following to work with:
- Shimano RX100 7-speed downtube shifters
- Shimano "Light Action" rear derailleur (7-speed I presume)
- Shimano Ultegra 8-speed cassette (11-23 I think)
- Formula 8/9 speed hub
- 4mm spacer
First, will the RX100 7-speed accomodate an 8-speed cassette in friction mode? Will the Light Action RD have enough range to do 8-speed? (If not, I have a 8/9 speed Sora RD that should do the trick.)
Secondly, if I wanted to run indexed, I'd have to get a 7-speed cassette-- because the 8-speed cassette has the wrong spacing, correct? I couldn't just add the spacer and omit the 11t cog?