STI for 7speed Freewheel

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daddig
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STI for 7speed Freewheel

Postby daddig » 30 Mar 2015, 8:50pm

Guidance please ?
I have a 1970 Holdsworth to which I have fitted a 7 speed freewheel , currently I use down tube changers ! I have however a set of Shimano STI brake/ gear shifters , not sure of type , they gear cables coming out of the side !
My question is can I fit these and use on my 7speed freewheel , gears are Shimano Acero !
Mike G

Brucey
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Re: STI for 7speed Freewheel

Postby Brucey » 30 Mar 2015, 9:38pm

if the STIs have six clicks or seven clicks that makes them 7s or 8s and then 'yes' is the answer.

If they have 8 clicks then they are 9s and the answer is 'no' not without a fair bit of messing about.

BTW all STIs will have the model number on them somewhere.... this is a definite help in IDing such things.

cheers
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daddig
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Re: STI for 7speed Freewheel

Postby daddig » 30 Mar 2015, 9:47pm

They have 9clicks Brucie, so how complicated is it fit ?
Mike G

Brucey
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Re: STI for 7speed Freewheel

Postby Brucey » 30 Mar 2015, 9:52pm

9 clicks, ten positions, or 8 clicks, nine positions?

If the former, forget it. If the latter, you may get away with it if you can move the cable attachment point on the rear mech (by about 10% to the relevant pivot). A bit like the Dura-Ace 9s/8s conversion.

DO try and find the model number of the STIs you have. All will be clear then.

cheers
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daddig
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Re: STI for 7speed Freewheel

Postby daddig » 30 Mar 2015, 10:02pm

8 clicks 9 positions , they came off a Revolution World , disc brake version !
Though will get model number tomorrow !
Thanks for your help Brucie .
Mike G

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gaz
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Re: STI for 7speed Freewheel

Postby gaz » 30 Mar 2015, 10:34pm

If there is a front derailleur involved and it is also Acera (or any other MTB model) it will not index with road STI levers.
2020 : To redundancy ... and beyond!

BigG
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Re: STI for 7speed Freewheel

Postby BigG » 31 Mar 2015, 5:42pm

I think that the difference between a 9 speed (4.35 mm sprocket spacing) and a 7 speed (5.0 mm sprocket spacing is too much. A shiftmate 2 might help (a 10% increase in wire pull) but even this is not really enough. I don't think that shiftmate has a 15% version that you would need.

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: STI for 7speed Freewheel

Postby Brucey » 31 Mar 2015, 5:47pm

BigG wrote:I think that the difference between a 9 speed (4.35 mm sprocket spacing) and a 7 speed (5.0 mm sprocket spacing is too much....


but isn't it almost identical to the (shimano recommended, cable mounting repositioning) Dura-Ace 8s/9s adaptation? If so I can't see how it can be 'too much' for a similar solution.....?

cheers
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daddig
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Re: STI for 7speed Freewheel

Postby daddig » 18 Apr 2015, 6:07pm

An update , though a big thanks for the advice given . I decided to give it a whirl , the result when I tried the cable reposition ( Shimago) didn't work well ! However after reading more by Sheldon Brown I clicked to first position on STI and set cable as normal . The result a working 7speed change !
As I use a double up front of 44 / 26 a Shimano Double changer is fitted and works well !
Mike G