XC Pro thumbies...are they all 8spd capable??

[mikede]

Like the title says, are they all 8spd capable?? Do they have the 'extra' click like the XT thumbies?

 

[ishaw]

I believe they do (7 speed), so in theory the 8 speed ones could run 9 speed, though I'm sure someone knowledgable in such things will correct me and provide detail about ratios, spacing and other important details I don't have.

 

[euphras_1]

Unfortunately no. The thumb shifters have index rings with a given number of deepenings in which the index balls rest.

An 7 speed index ring:

An 8 speed ring (XC Pro Microdrive):

There´s no way to convert an 7speed thumby into an 8speed others than grinding additional holes into the index ring or designing it from scratch.

Some writing about the innards of SunTour thumb shifters by me :

http://euphras.blogspot.de/2011/10/how- ... index.html

 

[Canuck]

Don't know much about Suntour thumbies and don't know if they're all the same but I do know that my '94 Kilauea came with Suntour XC Pro thumbshifter's running an 8 spd cassette straight out of the factory...don't know if that helps Really good shifter's as well

 

[Canuck]

Oops, just saw what euphras_1 wrote so there ya go - look's like they're not all the same

 

[euphras_1]

but I do know that my '94 Kilauea came with Suntour XC Pro thumbshifter's running an 8 spd cassette straight out of the factory.

Yes, that was the "last battleship" of SunTour, the XC Pro 8 speed Microdrive. Those thumbies bear a mark on the outer plastic ring stating they´re capable to run BOTH 7speed AND 8speed cassettes. Those thumbies look like this:



Earlier 7 speed thumbies only bear a [7] marking in that area.

 

[mikede]

F me.

 

[sancho]

run it in friction mode--problem solved.

 

[mikede]

run it in friction mode--problem solved.

No, I want clicky-clicky...oh, well. I'll have a Daily sooner or later to use them on

 

[euphras_1]

run it in friction mode--problem solved.

No, I want clicky-clicky...oh, well. I'll have a Daily sooner or later to use them on

Go on a hunt for XC EXPERT thumbies in the bay. They´re only available as an 8speed version and normally they sell for a fraction of the cost of XC Pro ones. If you want the look of XC Pro you can always transplant the index ring from the XC Expert thumbie to the XC Pro casing.