u/AssistanceMental5245

I’m building a new bike and am having issues with the front derailleur.

It’s an l-twoo erx v3 groupset with shimano ultegra chainrings 50-34. I am using a magene p515 spider.

I have set the limit on the front derailleur as close to the frame as it will go, but there is a massive gap between the outer part of the cage and the chain. When I try shifting to the small chainring the cage barely touches the chain and doesn’t shift.

I have ordered some spacers designed for a 24mm spindle to put between the bb and crank set. Do you think this is the right approach? Has anyone dealt with this combo or similar before? Any other ideas or fixes?