no it is not possible to untaper a tapered steerer. and no you can not use that bottom cup in a normal head tube for 1 1/8" your frame has to be designed specifically for tapered steerer forks.
@drøn started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
no it is not possible to untaper a tapered steerer.
and no you can not use that bottom cup in a normal head tube for 1 1/8"
your frame has to be designed specifically for tapered steerer forks.