The Soma Rufus is a "mini velo" frameset designed for 20" BMX tires up to 2.3"
Available in the US and soon elsewhere. Custom spec it yourself (or with your bike shop) with whatever bars or gearing suits you. Disclosure: This bike review is by someone who works at the company, but is giving his honest assessment after riding for a few months. Frame is a size SM. Reviewer is about 5' 6". ミニベロ
More info:
https://www.somafab.com/archives/product/soma-rufus-mini-velo