Plastic thingie

[Birddog]

I'm in the process of building up a bike with Ultegra 6800. Included in the build kit with the FD is a plastic thingie that you use to make some sort of adjustment to the FD. A check on the Shimano site gives me an explanation that I can't understand and a check on YouTube gives me nada. What is that dealiebob for and how does one use it? Is it really necessary? TIA

[Tony T]

Are you referring to the "backup plate"?
"If installing the front derailleur to a brazed-on type frame, a backup plate must be attached to the seat tube. Always be sure to install the backup plate in order to prevent damage to the frame from the pressure applied by the support bolt of the front derailleur."

See: http://si.shimano.com/php/download.php?file=pdf/dm/DM-FD0002-03-ENG.pdf

[oldpotatoe]

I'm in the process of building up a bike with Ultegra 6800. Included in the build kit with the FD is a plastic thingie that you use to make some sort of adjustment to the FD. A check on the Shimano site gives me an explanation that I can't understand and a check on YouTube gives me nada. What is that dealiebob for and how does one use it? Is it really necessary? TIA

It shows you which way the front der cable and attach nut/plate is oriented. Yes, it can be confusing.

https://www.youtube.com/watch?v=hlbenKUx9JM

[GScot]

I assume you mean the cable placement evaluator. Look up the Shimano dealer manual for a description and note that it has instructions for all series, 6800 is a bit different than 9000.

Basically you slide it into place on the derailleur and stretch the cable through the top slot where the clamp would be. The side of the line it falls on determines which direction that little pin below the clamp will face/cable routing.