User blog comment:Master Sima Yi/Assassinews 12-05-'15 — Assassin's Creed: Syndicate has been revealed!/@comment-746824-20150513005724/@comment-746824-20150513022510

The Helix is a plot element in the series, it being a server/cloud computing memory repository. The databases of Rogue, Unity, Identity, and Chronicles: China (and presumably that of Chronicles: India and Chronicles: Russia as well in addition all components of Memories) are all part of Helix.

This wiki compiles information based on the series, including database entries. These used to be organized by game, but are now organized from an in-universe PoV. This means that all those games theoretically share the same database. Helix 4.0 is (apparently) the first distinction for the Helix in-universe.

This has nothing to do with bicycles, Anon.