What is Ko Zieleman?
'''Ko Zieleman''' (1933–2021) was a Dutch bicycle racer and bicycle builder. He assembled custom bike frames.<ref>{{Cite web|url=https://www.klassiekeracefiets.info/fietsmerken/zieleman/|title=Zieleman}}</ref> He was born on 10 January 1933 in Amsterdam.<ref>{{Cite web|url=https://www.cyclingranking.com/rider/14353/ko-zieleman|title=Historic Overview Ko Zieleman}}</ref> In 1959, he raced from Gent to Wevelgem .<ref>{{Cite web|url=https://www.procyclingstats.com/rider/ko-zieleman|title=Ko Zieleman}}</ref> He had a bike shop in Ansterdam.<ref>{{Cite web|url=https://www.wielerflits.nl/nieuws/fietsenbouwer-ko-zieleman-88-overleden/|title=FIETSENBOUWER KO ZIELEMAN (88) OVERLEDEN|date=13 April 2021}}</ref><ref>{{Cite web|url=https://www.parool.nl/amsterdam/voor-groenewegen-was-ko-zieleman-1933-2021-de-allerbeste-opa~b8f5c792/|title=Voor Groenewegen was Ko Zieleman (1933-2021) de allerbeste opa|date=13 April 2021}}</ref> His grandson is Dylan Groenewegen.<ref>{{Cite web|url=https://netherlandsnewslive.com/dylan-groenewegen-mourns-famous-grandfather-ko-he-put-together-the-first-bicycle-cycling/133480/|title=Dylan Groenewegen mourns famous grandfather Ko: 'He put together the first bicycle'|access-date=2021-12-23|archive-date=2021-12-23|archive-url=https://web.archive.org/web/20211223162207/https://netherlandsnewslive.com/dylan-groenewegen-mourns-famous-grandfather-ko-he-put-together-the-first-bicycle-cycling/133480/|url-status=dead}}</ref><ref>{{Cite web|url=https://www.telegraaf.nl/sport/1674645643/dylan-groenewegen-rouwt-om-bekende-opa-ko-hij-zette-eerste-fietsje-in-elkaar|title=Dylan Groenewegen rouwt om bekende opa Ko: 'Hij zette eerste fietsje in elkaar'|date=14 April 2021|access-date=23 December 2021|archive-date=23 December 2021|archive-url=https://web.archive.org/web/20211223162402/https://www.telegraaf.nl/sport/1674645643/dylan-groenewegen-rouwt-om-bekende-opa-ko-hij-zette-eerste-fietsje-in-elkaar|url-status=dead}}</ref><ref>{{Cite web|url=https://www.volkskrant.nl/nieuws-achtergrond/als-bouwer-van-racefietse