Bicycle Mechanics - Convert downtube to STI

Hi all,

Is is possible to convert a shimano seven speed downtube shifters to STI? I know the older STI shifters aren't that good. Can the 9 speed shifter be made to work with a seven speed cassette?

7 speed Sora STI would be a great choice.

Older Shimano 7-speed RSX were good and functional shiftrer with decent reliability. Sora shifters are a less convenient design but work ok.

9-speed shifters won't work with a 7-speed cassette since the cog spacing is different. One work-around is to install 8 cogs of a 9-speed cassette on a 7-speed freehub and lock out one click with the limit screws. That gives you compatible 9-speed spacing, lets you use your 7-speed hubs and adds one more cog to your choices.

Hi all,

Is is possible to convert a shimano seven speed downtube shifters to STI? I know the older STI shifters aren't that good. Can the 9 speed shifter be made to work with a seven speed cassette?

Yes, they have sora 7 speed STI still available everywhere.

See this page (http://sheldonbrown.com/dura-ace.html)

In practice, since 7 speed and 8 speed spacing are very similar, you could use a 9-speed shifter with your 7-speed cassette if you install the cable according to the alternate cable routing (see link above).

Or build your own 8-speeds-out-of-9 cassette. (see this (http://sheldonbrown.com/k7.html))

Wouldn't it be alot easier to just put a nine speed wheel on the back? If your riding a seven speed I'm guessing you have 126 rear spacing and spreading to 130 would not be that hard.

if the bike is steel, this is true. Unfortunately, aluminum will weaken if spread even that much. I say pick up a shimano 8-speed cassette and older 8-speed shifters. That's what I plan to do on my commuter once I wear out the wheels.