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-   -   Shift a SA 5-speed with SRAM 10 speed and Jtek Shiftmate? (http://www.bikeforums.net/bicycle-mechanics/941650-shift-sa-5-speed-sram-10-speed-jtek-shiftmate.html)

roburrito 04-04-14 11:18 AM

Shift a SA 5-speed with SRAM 10 speed and Jtek Shiftmate?
 
As far as I understand, a newer Sturmey Archer 5 speed hub has 20mm total cable pull and ~5mm between gears. A SRAM 10-seed shifter has 3.1mm pull between clicks. According to the chart on Sheldon Brown's site, the Jtek Shiftmate #6s has a 1.619 ratio.

3.1mm * 1.619 = 5.02mm

So should this work? Am I crazy for wanting to try this?

Retroshift would be a cheaper option if I didn't have a SRAM Rival shifter sitting in my parts bin. FWIW I'm currently shifting an SRF5 with a SA bar-end.

fietsbob 04-04-14 12:21 PM

Try and report ..


I guess you are wanting a Road Drop bar brifter setup?

Id use a regular brake lever and the SA bar end shifter with detents for their 5 speed .

lostarchitect 04-04-14 12:42 PM

Quote:

Originally Posted by fietsbob (Post 16641961)
Try and report ..


I guess you are wanting a Road Drop bar brifter setup?

Id use a regular brake lever and the SA bar end shifter with detents for their 5 speed .


+1, the SA bar end works very well on drop bars. Or you can get the thumb shifter version--it will mount easily on most quill stems.

roburrito 04-04-14 01:14 PM

I have the bar ends. They work fine. I like brifters. I like causing unnecessary problems for myself too.

fietsbob 04-04-14 01:37 PM

Eyeing them who ever makes the parts branded ' Microshift' seems to also be who S-R_S-A went to to make their shift levers ..

Taiwan is not that an big Island and the Taipei trade show hall probably near to places to go out for drinks together each night after closing the Show.

maybe those retroshift things will take the same shift lever as The 5 speed does in its own 2 mounts.

test and report.

lostarchitect 04-04-14 02:37 PM

Quote:

Originally Posted by roburrito (Post 16642122)
I have the bar ends. They work fine. I like brifters. I like causing unnecessary problems for myself too.

Gotcha. Well, I say go for the experiment! Let us know how it works.

Dan Burkhart 04-05-14 08:27 AM

Quote:

Originally Posted by roburrito (Post 16641757)
As far as I understand, a newer Sturmey Archer 5 speed hub has 20mm total cable pull and ~5mm between gears. A SRAM 10-seed shifter has 3.1mm pull between clicks. According to the chart on Sheldon Brown's site, the Jtek Shiftmate #6s has a 1.619 ratio.

3.1mm * 1.619 = 5.02mm

So should this work? Am I crazy for wanting to try this?

Retroshift would be a cheaper option if I didn't have a SRAM Rival shifter sitting in my parts bin. FWIW I'm currently shifting an SRF5 with a SA bar-end.

Here are the cable pull increments of a Sturmey Archer 5 speed wide range shifter as measured on my cable pull measurement tool.

Over all 20.6 mm
1st to 2nd-7.3 mm
2nd to 3rd-3.6 mm
3rd to 4th-3.6 mm
4th to 5th-6.1 mm

As you can see, the increments are NOT equal.

Dan Burkhart 04-05-14 11:08 AM

Quote:

Originally Posted by Dan Burkhart (Post 16643800)
Here are the cable pull increments of a Sturmey Archer 5 speed wide range shifter as measured on my cable pull measurement tool.

Over all 20.6 mm
1st to 2nd-7.3 mm
2nd to 3rd-3.6 mm
3rd to 4th-3.6 mm
4th to 5th-6.1 mm

As you can see, the increments are NOT equal.

Compare these numbers to the cable pull increments of the older model SA 5 speed.
over all cable pull is 22.2 mm
1st to 2nd -6.8
2nd to 3rd -3.9
3rd to 4th -5.9
4th to 5th -5.6

roburrito 04-07-14 09:00 AM

Drats. Thanks for the info, Dan

retroshift 04-14-14 08:23 AM

Quote:

Originally Posted by fietsbob (Post 16642205)
Eyeing them who ever makes the parts branded ' Microshift' seems to also be who S-R_S-A went to to make their shift levers ..

Taiwan is not that an big Island and the Taipei trade show hall probably near to places to go out for drinks together each night after closing the Show.

maybe those retroshift things will take the same shift lever as The 5 speed does in its own 2 mounts.

test and report.

The Retroshift CX shifters can be purchased without shift levers and will accept Sturmey Archer 3 or 5 speed levers no problem!

XOXO

Goats

Kimmo 04-15-14 08:55 AM

I reckon a CAD whiz could knock up an eccentric pulley (with a stop for calibration) to suit, and it's the sort of component that's amenable to 3D printing.

An inline Shiftmate frame would be the go.


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