drivetrain voodoo. does your shifting do one thing on the stand, and something else

[Catagory6]

when out on the road?
even it its a super-stiff carbon frame?
i set the FD in the stand, and then out on the road the gap between the inside cage and the inside chain opens up a little bit.
i've had the bike for about 3 years and never noticed this before.
i guess it could have always been this way.

but is this normal?

[Rudi]

Occasionally. I've always assumed this is because the "system" is under load on the road where as there is not a lot of resistance when on the stand.

This is more RD indexing for me, not sure I've noticed FD issues as much.

[bikeboy1tr]

Yes its always different out on the road for both (FD and RD) compared to when you set it up in the shop. Even when I am on the rollers the FD will not shift the way it will in the shop and out on the road. When I am setting it up in the shop I just get it close to where its shifting acceptably and then head outdoors to fine tune the shifting. Yes I believe it is different shifting when the frame has a load on it compared to no load in the shop. If I go out and do sprint intervals I sometimes have to make shifter adjustments cause I am heavy and I stand when sprinting so it makes more load on the frame. Think it might be dynamics of rocking the frame back and forth under full force.

[ChiZ01]

when your body weight in on the bike, the seat tube will flex a little, the heavier you are the more it will flex

[Catagory6]

ok, thanks
this makes me feel better

guess i need to shed my winter coat

[ParisCarbon]

Yep.. had Dura Ace di2 absolutely flawless on the stand in shop and at home, get it on the road, and half the time it refused to drop to the 11 cog unless I back off to the 13 and brought it down to the 11... put it on the stand and it worked fine.. also experienced random ghost shifting with the FD on the road.. would just drop to the 39 for no reason at all!! I switched to EPS...

[Nefarious86]

Yep.. had Dura Ace di2 absolutely flawless on the stand in shop and at home, get it on the road, and half the time it refused to drop to the 11 cog unless I back off to the 13 and brought it down to the 11... put it on the stand and it worked fine.. also experienced random ghost shifting with the FD on the road.. would just drop to the 39 for no reason at all!! I switched to EPS...

That's nothing more than poor setup.

Sent from my SM-G975F using Tapatalk

[spdntrxi]

this is very common for me as well... I always need a couple clicks of trim either direction once on the road... extra 20 seconds and I'm done.

Same goes for my brake rotors... my fat arse changes them one I put power down.. the direction is consistent so I can account for it more times then not.

[mattr]

Never. Every bike i have built/setup from scratch works the same on stand and road. (And trainer).

Bikes I've acquired from elsewhere sometimes don't, but they're usually badly cabled, bent hangers or any number of other issues.

[Alexandrumarian]

Same here, I'm heavy and there is always a bit of adjustment needed, typicaly an increase of rear tension and decrese in front (campy).

As for voodoo or maybe poor setup, I recently gave up on Squirt and switched to Shimano ptfe. As a result I had to back off the rear tension several clicks.

[ryanw]

Never. Every bike i have built/setup from scratch works the same on stand and road. (And trainer).

Bikes I've acquired from elsewhere sometimes don't, but they're usually badly cabled, bent hangers or any number of other issues.

Spot on.

Never had an issue when 107kg and still don't have any at 85kg...

You just need to learn how to setup a bike properly

[wheelsONfire]

Never. Every bike i have built/setup from scratch works the same on stand and road. (And trainer).

Bikes I've acquired from elsewhere sometimes don't, but they're usually badly cabled, bent hangers or any number of other issues.

+ 1

[ParisCarbon]

Yep.. had Dura Ace di2 absolutely flawless on the stand in shop and at home, get it on the road, and half the time it refused to drop to the 11 cog unless I back off to the 13 and brought it down to the 11... put it on the stand and it worked fine.. also experienced random ghost shifting with the FD on the road.. would just drop to the 39 for no reason at all!! I switched to EPS...

That's nothing more than poor setup.

Sent from my SM-G975F using Tapatalk

Doubt it... 2 certified mechanics, rd dropout alignment, current firmware.. we were thinking somethng internal with the battery itself.. will never know, its EPSd now

[timmerrr]

Yep.. had Dura Ace di2 absolutely flawless on the stand in shop and at home, get it on the road, and half the time it refused to drop to the 11 cog unless I back off to the 13 and brought it down to the 11... put it on the stand and it worked fine.. also experienced random ghost shifting with the FD on the road.. would just drop to the 39 for no reason at all!! I switched to EPS...

That's nothing more than poor setup.

Sent from my SM-G975F using Tapatalk

Doubt it... 2 certified mechanics, rd dropout alignment, current firmware.. we were thinking somethng internal with the battery itself.. will never know, its EPSd now

I had something very similar when i first started riding da di2. Didn't realize that I was accidentally tapping the shift button with my natural hand position occationally. Took about a week to figure out what was actually going on.

[ParisCarbon]

Yep.. had Dura Ace di2 absolutely flawless on the stand in shop and at home, get it on the road, and half the time it refused to drop to the 11 cog unless I back off to the 13 and brought it down to the 11... put it on the stand and it worked fine.. also experienced random ghost shifting with the FD on the road.. would just drop to the 39 for no reason at all!! I switched to EPS...

That's nothing more than poor setup.

Sent from my SM-G975F using Tapatalk

Doubt it... 2 certified mechanics, rd dropout alignment, current firmware.. we were thinking somethng internal with the battery itself.. will never know, its EPSd now

I had something very similar when i first started riding da di2. Didn't realize that I was accidentally tapping the shift button with my natural hand position occationally. Took about a week to figure out what was actually going on.

I was on the tops everytime it happened! Its weird because my Shiv TT bike with Di2 has been great!!