|STI history/updating advice needed||Trimaniac|
Feb 3, 2002 7:36 PM
|I have an older Vitus 979 with 126mm spacing. Currently, it is equipped with an Ultegra rear der and STI levers shifting a 7speed freewheel. I would like to upgrade to Dura Ace ( to match the rest of the bike) What model numbers of STI levers and rear der do I need to be looking for?
|re: STI history/updating advice needed||Rusty Coggs|
Feb 3, 2002 8:22 PM
|8 speed DA shifters and pre 9 speed DA rear der, will shift your 7 speed freelwheel(are you sure it's not a cassette?) as well as the ultegra(STI shifters too?) stuff is doing it.Shimano 7 and 8 speed cog spacing are different, but close enough that shimano 8 shifters usually works. the pre 9 speed DA shifters and rear derailers have unique cable pull /derailer throw ratios and have to be used together.Your Al frame dies not take well to being spread to use 8,9,10, speed hub spacing of 130mm. If you have a 7 speed cassette, or a new wheel is in the plan, Sheldon Brown at www.harriscyclery.com has an article on using a 7 speed shimano cassette hub(126mm) and a 9 speed cassette with a cog and a spacer removed,to make it 8 speed, and shifted with a 9 speed shifter. Sounds bizarr but it works.Also requires a 9 speed chain.|
|I've had less luck||laffeaux|
Feb 5, 2002 10:53 AM
|I tried putting an 8-speed cassette on a bike with 7-speed STI shifters (RSX), and could not get it to work. It's similar (but opposite) of what you, or rather Sheldon Brown, suggest. The 7-speed has an extra "pull" beyond the 7th click. I thought it might work, but it didn't. It shifted okay if you always went forward or back in the gears. However if you tried to go 1/2 way through the cassette (i.e. high to low) and then reverse directions (low to high) the shifting was really bad. |
I agree with your "spread the frame" idea.