Suntour XC Pro Thumbshifter rebuild and upgrade

[Tootyred]

Dont know if this will help anybody, but there seems to be loads out there on rebuilding shimano xt / deore shifters, but not much on Suntour xc pro / comp.

So as i want to go 8 speed on my next project, i thought i might strip one down for you boys and girls...you never know when the info might come in useful or get somebody out of trouble!

I will do it in steps with as many pictures as i can add.....but they are fairly straight forward beasts....

 

[Tootyred]

So, here is the guts all laid out in a row......ive got 2 apart as im doing a transplant of the 7 to 8 speed bit at the same time. Unlike xt shifters, these really are 8 speed...ie there is actually a recess drilled for 8 speed on the 7/8 switchable version.....not a spring hole!

Also unlike xt the mechanism if far simpler as there is no internal spring, instead they rely on 2 concave and a wave washer to provide tension. Far less to go wrong, lighter, less prone to becoming wobbly at the lever.

Ive used these since they first come out in 91 ish....in fact the set on my daily drive are those! Nuff said really as to reliability.

Tools needed are a pick and possibly a small screwdriver....and thats just to remove / replace the circlip.....everything else is tool free.

To get them apart is simple....unscrew the top cap. That releases the lever from the body. Under that is a single circlip....thats it.....try to keep your thumb over the circlip as they will go flying...gently lever it out with the pick.

 

[Tootyred]

Then basically take the piece out as they are presented to you. Lay them out as they come off. Take photos if you cant remember any smaller details...

Once all out and clean im going to swap the 8 speed plate from my broken clamp donor XC comp. Pro and comp are identical save the colour of the lever, top cap design and the pattern on the adjuster. You will also need to swap the top ring with the markings on it for 7 /8 /friction....there is no actual difference, its just without it you would be fishing in the dark to locate the line up of the holes internally.

In the picture the selector plate is pushed forward along with a couple of other parts im swapping, just as they are in better condition...

 

[Tootyred]

Reassembly is the same in reverse...but just incase you are in trouble....here goes.

Put the wave washer onto the spline.

 

[Tootyred]

Put the lever onto the spline.

 

[Tootyred]

Put the copper washer onto the spline

 

[Tootyred]

Next take the 2 concave washers. These need to be on top of each other. These form the spring. You will see the orientation....bottom cone down...top cone up..

 

[Tootyred]

Next is the second copper washer.

Thats your spring done...

 

[Tootyred]

Now it gets more interesting. Put the dimpled selector plate in, dimples up. It can go in either way round 0 or 180 degrees. You cant put it in the wrong slots as it wont fit as the tags are different sizes...

Ive also added a shot of the 2 different plates....

 

[Tootyred]

Now the larger thin copper washer. And add the 2 bearings.