Shimano st-rs685 front shifting behavior

[Dave]

hey all,

Just got a (used) bike with st-rs685 shifters (hydraulic brakes, 2x11 mechanical shifting). The behavior of the front shifter is strange, I am trying to understand whether my shifter is defective or not.

Per shimano, I understand that these front shifters have a total of 4 FD positions. From outboard to inboard, these are: high, high trim, low, low trim (this is the innermost position).

When the chain on the big ring, a complete sweep of the small lever triggers 1 or 2 clicks (from the high trim and high positions respectively) and leaves the FD positioned in the 'low' position. To move the FD into the low trim position (all the way inboard) requires two sweeps of the small lever.

Is this as designed?

[jbeattie]

I've got those levers on my disc Roubaix and couldn't tell you the answer -- meaning that they act (or are supposed to act) exactly as ordinary STI shifters. They are so normal that I don't even remember how they shift. I'll play with them on the way to work the morning and let you know.

-- Jay Beattie.

[Lou Holtman]

That is correct and as designed.

--
Lou

[Duane]

I had them on my last bike and I think it works the way he's describing.
The trim was always a bit tricky for me though.

[cycl...@gmail.com]

On Thursday, September 15, 2016 at 7:28:14 PM UTC-7, Dave wrote:

Although you have described if a bit confusing I believe you have a correctly working shifter.

I don't know how Shimano describes it but I would call it low, low trim, high trim and high.

[jbeattie]

That's right, confirmed on my ride in. The Roubaix has the proprietary SCS hub spacing and derailleur placement to improve chain alignment, so I don't get many alignment issues and never use the low trim. I'm switching to regular wheels eventually and changing hangers to do that, so it may become more of an issue in the future.

BTW, I'm so glad I did not buy a Diverge with its proprietary through axles, hub spacing, etc., etc. A lot of impulse buyers have been pretty pissed off after finding out that its impossible (or really expensive) to use OTC 135mm through-axle wheels on that bike. You're practically locked into to their wheel offerings.

-- Jay Beattie.

[Dave]

On Thursday, September 15, 2016 at 7:28:14 PM UTC-7, Dave wrote:

thanks all, I've since learned that Shimano introduced this to reduce inboard chain derailment. I wonder whether the switch from 10 to 11 speeds worsened this tendency so required them to make this change.

personally I don't care for it.

[Duane]

I had it on my 10 speed 105 setup.