can one use 9 speed STI shifters with an 8speed cassette and r/d? if not, what would you suggest to use for the shifting mechanism? are there 8 speed STI’s or would i have to use downtube shifters?
many thanks…
Well, yes and no. You can do a down and dirty install, locking out the last click on the shifter by adjusting the limit screws on your rear derailleur, but the shifting will be less than perfect most likely.
Or, you can replace the spacers in your 8 spd cassette with narrower spacers to get the same spacing as the 9 spd (I believe the change to 9 spd required a narrower chain).
Check out Sheldon Brown’s website; he has a great spacer chart and talks about compatibility if I’m not mistaken.
Good luck.
Also, you can get 8-speed shifters (STI, bar-end, and downtube) at the Harris Cyclery website.
Also, if you do go the 9-speed STI route and lock out a click, make sure it’s not at the big-cog end – you can jam the shifter and it’ll be stuck for life. Make sure that extra click is beyond your high gear.
There’s dude in the Minneapolis area named Jay Guthrie who makes cable pull convertors. They look like a problem solvers travel agent but mount like an Avid rollamajig. I’ll bet he makes on to convert 8 spd shimano to 9 spd and vice versa.
awesome. all that is great information, just what i was looking for. i will figure something out.
According to others more in the know than I am, just get a 9 speed cassette and Bob’s your uncle.
The pull ratios on the derailleurs are the same from 8 to 9 speed just the width is different. So it should work for you, or more properly it will work at least as well as using a 9 speed shifter to shift an 8 speed cassette.
but i have an 8spd derailleur…
Maybe you missed it the first time, I’ll explain a bit more.
The pull ratios on the derailleurs are the same from 8 to 9 speed just the width of the cage is different. So it should work for you, or more properly it will work at least as well as using a 9 speed shifter to shift an 8 speed cassette.
I’ll second what Kevin said. On one of my bikes, I’ve got 9-speed STI shifters and cassette working with a 6-speed 105 rear der (ca. 1987). It doesn’t shift 100% perfect, but it’s at least 95%. With your 9-speed shifters and going from 8 to 9 should offer you no difficulties at all if you just change the cassette.