Formatting chapter header with titlesec

Im having troubles in formatting chapter headings. Im doing it with the package titlesec. My goal is to have the chapter number on the left, than a line with above the chapter name. I achieved this with the following minimal working example. But I can not figure out how to increase the size of the chapter name in this code?

RequirePackage{filecontents}
begin{filecontents*}{test1.tex}
    chapter{Chapter One}
    Text123
    Text123
    Text123
end{filecontents*}

documentclass[a4paper, liststotoc, bibtotoc, 12pt, numbers=noenddot, twoside]{book} 

usepackage{fancyhdr}

usepackage[explicit]{titlesec}
newlengthchapnumb
setlengthchapnumb{4cm}
titleformat{chapter}[block]
{normalfontsffamily}{}{0pt}
{parbox[b]{chapnumb}{%
        fontsize{100}{10}selectfontthechapter}%fontsize number
    parbox[b]{dimexprtextwidth-chapnumbrelax}{%
        raggedleft%
        hfill{LARGE#1}
        rule{dimexprtextwidth-chapnumbrelax}{0.4pt}}}
titleformat{name=chapter,numberless}[block]
{normalfontsffamily}{}{0pt}
{parbox[b]{chapnumb}{%
        mbox{}}%
    parbox[b]{dimexprtextwidth-chapnumbrelax}{%
        raggedleft%
        hfill{LARGE#1}
        rule{dimexprtextwidth-chapnumbrelax}{0.4pt}}}

begin{document}
    include{test1}
end{document}

Many thanks for your help!!