9 speed shifters with 7 speed cassette

The Spiderman

I have an old 531 steel road bike which I use for commuting.I recently fitted a new pair of wheels and an HG 70 7 speed cassette with a spacer.(Currently has old campag 7 speed shifters)

If I swap to 9 speed sti shifters can they be made to work,with a 7 speed cassette,by screwing in the l limit adjuster,and thus locking out the last 2 shifts?

Steve928

Your best bet is to use 9 speed Campag Ergos (post-2001) as these pull the same amount of cable as 7 speed Shimano shifters. Stick with the Shimano rear mech and it should all work perfectly - the rear mech limit screws will block out the extra 2 shifts.

Edit: that's presuming you have a Shimano rear mech currently..

alan_sherman

9 speed (shimano) shifters won't work with a 7 speed (shimano) cassette unless you use a shiftmate.

However Sheldon brown has an alternative solution. He says you can use 8 of the 9 sprockets from a 9 speed cassette on a 7 speed freehub.

Read here:
http://sheldonbrown.com/k7.html

aracer

SteveNcp wrote:

Your best bet is to use 9 speed Campag Ergos (post-2001) as these pull the same amount of cable as 7 speed Shimano shifters. Stick with the Shimano rear mech and it should all work perfectly - the rear mech limit screws will block out the extra 2 shifts.

Edit: that's presuming you have a Shimano rear mech currently..

Not according to the bible on mixing and matching at http://www.ctc.org.uk/DesktopDefault.aspx?TabID=3946 they don't - 3.0mm vs 2.9mm. Old Campag 9-speed with Hubbub cable routing would seem to be the only workable solution according to that

alan sherman wrote:

However Sheldon brown has an alternative solution. He says you can use 8 of the 9 sprockets from a 9 speed cassette on a 7 speed freehub.

Though the OP already has an 8-speed freehub (new wheels and spacer) so could put the complete 9-speed cassette on if doing that.

Doesn't look like there's an easy solution I'm afraid!

Steve928

I don't subscribe to the CTC religion, rather I was speaking from experience, having run 2 bikes like that for many miles. That combination indexes perfectly. Not close, or close enough, but perfectly.

I have cable pull figures of 3.00mm for Shim7 and 3.05mm for Campag9, but I've no idea where they came from!

John.T

If you are going to buy 9sp STIs then you might as well spend a little more and get the cassette and chain as well. The STIs are by far the most expensive item.
If you have an old Shimano 7sp rear mech it may not move far enough to reach all 9 cogs. If not just use the limit stops for the ones you can get. There will be at least 8.

rustychisel

I've played with this a bit.

On a seven speed freehub use a 7 speed cassette and limit out the last 2 clicks, as said.
Or find a 9 speed cassette, using 8 of 9 cogs and limit out the last click.

Or, as indicated, get a 9 speed cassette for your new wheels. Done, the best option.

The Spiderman

IThanks for the input.I think I will run it wth good old downtube shifters for now and invest in a full 9 speed set up later,once I've got the rest of the bike set up sorted.