Bicycle Mechanics - How do I adjust my STI brifter from a triple to a double ?

Hi All,

I have a 10spd 50-39-30 triple and I'm switching to a Shimano FC-R700 compact crank 50-34. Since the 50t will be the same all I should have to do is adjust my front brifter to a double setting from a triple.

That said, how do I do this ???

You don't do anything to the brifter. Just adjust the limit screw on the FD so it doesn't move inward further than the inner ring on the double. You simply end up with one position on the brifter that won't be used.

You don't do anything to the brifter. Just adjust the limit screw on the FD so it doesn't move inward further than the inner ring on the double. You simply end up with one position on the brifter that won't be used.

The lower limit screw ? That's it ?? Do I have to do anything else before or after I do that ??

The more I think about it the double chainrings might not be spaced from the frame exactly where the middle and outer rings are now on the triple. A little farther in or out. So you might end up having to adjust both limit screws to shift properly without overshifting. Maybe a cable adjustment also. That's about it.

The more I think about it the double chainrings might not be spaced from the frame exactly where the middle and outer rings are now on the triple. A little farther in or out. So you might end up having to adjust both limit screws to shift properly without overshifting. Maybe a cable adjustment also. That's about it.


Hmmm...I was about to tackle this myself but the last thing I want to do is get the job done and have the bike shifting like crap.....Maybe I'll wait and have the LBS whack me for it....:mad:

The more I think about it the double chainrings might not be spaced from the frame exactly where the middle and outer rings are now on the triple.

Brifters and dérailleurs come as double or triple specific, so there is probably some merit to your point.

This might help http://sheldonbrown.com/speeds.html

Brifters and dérailleurs come as double or triple specific,

A 10-speed 50-39-30 triple sounds like a Shimano 105. Those shifters are double/triple compatible, they go both ways. When setup on a double there will be some unnecessary shift click positions (detents) that can be used for trimming if needed.

Al

A 10-speed 50-39-30 triple sounds like a Shimano 105. Those shifters are double/triple compatible, they go both ways. When setup on a double there will be some unnecessary shift click positions (detents) that can be used for trimming if needed.

Al

Interesting, DA and Ultegra have double / triple specific models, 105, Sora and Tiagra have the convertable.

Interesting, DA and Ultegra have double / triple specific models, 105, Sora and Tiagra have the convertable.
Yeah, but 9-speed Ultegras go both ways. On a double I'd rather not have the unnecessary extra clickstops.

Al

Yeah, but 9-speed Ultegras go both ways. On a double I'd rather not have the unnecessary extra clickstops.

Al

I have 10spd 105 STI. The left brifter can be either double or triple. On Ultegra and above they are separate brifter units.

I'm gonna wait and have my LBS do it.....:rolleyes:
Then at least I can point a finger if it isn't shifting properly.....;)

It's simple. When you set your limit screws on the derailluer the shifter can only pull the derailluer that distance. You can do this! Do it! DO IT!

It's simple. When you set your limit screws on the derailluer the shifter can only pull the derailluer that distance. You can do this! Do it! DO IT!

The Park Tool website makes it looking frightening...:eek:

http://www.parktool.com/repair/readhowto.asp?id=75

It's not as hard as Park makes it sound. Here's exactly what I would do:

1. Change the crankset to the new double.
2. See if it shifts well from the small to large ring and back.
3. If so adjust the lower limit screw so it doesn't over-shift the inner ring.
4. If not you can decide to do further cable, limit adjustments or have your LBS do it for you.

It's not as hard as Park makes it sound. Here's exactly what I would do:

1. Change the crankset to the new double.
2. See if it shifts well from the small to large ring and back.
3. If so adjust the lower limit screw so it doesn't over-shift the inner ring.
4. If not you can decide to do further cable, limit adjustments or have your LBS do it for you.


Do you have to do all the de-tensioning of the cables and barrel adjustments like the Park website is talking about ??

This is easy. I did this about two months ago. If you look at the brifter instructions on the Shimano website they explain that the extra click is used for trimming the FD.