DISRAELI GEARS

Sun-Bow

Sun-Bow derailleur main image Sun-Bow derailleur main image Sun-Bow derailleur main image

Sun-Bow is the brand of a company called Yamashita Iron Works Ltd. based at No. 36, Sambocho 4-cho, Sakai, Osaka Prefecture, Japan. The evidence for this is:

  • The patents covering the Sunbow derailleur are assigned to Yamashita Iron Works Ltd. based at No. 36, Sambocho 4-cho, Sakai, Osaka Prefecture.
  • One Sun-Bow derailleur that I have acquired had a brown card label attached to it saying ‘Yamashita Iron Works Ltd. YA-100 Rear Derailleur’. This Sun-Bow also shares some small parts with an SY derailleur that I have.
  • Two independant Japanese derailleur enthusiasts have noted that 'Sun-Bow' sounds very like 'Sambocho' - part of the address above. This use of 'soundalike' words has some form in the naming of Japanese brands. It's a story that is just weird enough to be true.

Two further pieces of relevant information are that:

It seems clear that SY derailleurs and Sun-Bow derailleurs were produced by the same company.

It's possible that Yamashita Iron Works Ltd. of Sakai is still in business today. The story might, possibly, be:

  • The company was established in 1902 as the Yamashita Ground Metal Shop.
  • It started producing bicycle components in 1947.
  • In 1973 the company appears to have changed its name to Koyo Giken Company Ltd, and then to have established Koyo Engineering Company Ltd in 1980.
  • It also appears that, in 1973, it changed its main business to producing engineered parts for furniture - and so it is possible that its interest in bicycle components declined from this point.
  • Koyo Corporation exists to this day. It has a history page on its web site.


Sun-Bow derailleur thumbnail


Sun-Bow 1977?


see also Japan's Bicycle Guide '56 1956

see also Japan's Bicycle Guide '56 1956

Japan's Bicycle Guide '56 - front cover thumbnail


see also Japanese Patent # S54-57737 - Sun-Bow 1977

see also Japanese Patent # S54-57737 - Sun-Bow 1977

Japanese Patent S54-57737 thumbnail


see also Japanese Patent # S54-67457 - Sun-Bow 1977

see also Japanese Patent # S54-67457 - Sun-Bow 1977

Japanese Patent S54-67457 thumbnail


see also Japanese Patent # S54-69550 - Sun-Bow 1977

see also Japanese Patent # S54-69550 - Sun-Bow 1977

Japanese Patent S54-69550 thumbnail


Sun-Bow - YA-100 label 1977?

Sun-Bow - YA-100 label 1977?

Sun-Bow YA-100 label thumbnail


see also New Cycling 05/1981 - Derailleur Collection

see also New Cycling 05/1981 - Derailleur Collection

  • Publisher: New Cycling
  • Date: May 1981
  • Derailleur brands: too numerous to list here
  • Derailleurs: too numerous to list here
New Cycling May 1981 - Derailleur Collection front cover thumbnail


see also Koyo Corporation - web site 2019

see also Koyo Corporation - web site 2019

  • Publisher: SY
  • Date: 2019
  • Derailleur brands: Sun-Bow, SY
  • Derailleurs: none
Koyo Corporation - web site thumbnail
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