[Alex D] - There is an electronic music company called cycling 74, who make MAX/MSP among other things; and it could just possibly be a reference to that.
[Mark S] - Many have suspected the title as being a reference to Albert Hofmann's trip on LSD known as Bicycle Day.
[Forfy] - The Peel Session version was used in season two, episode twelve of Six Feet Under.
The bass drum beat and dissonant note heard at the beginning and throughout the song are sampled from Pink Floyd's "Heart Beat, Pig Meat"[1] at 0:15. This sample can be heard better in "Bad Day".
The bird calls are sampled from "Vangelis - La Fête sauvage". There is also a sound like a man singing, rather faint and tinny. Sample starts at 2:43.[3][4]
The backmasked vocals beginning at 6:25 are of an interview with Jeff Lynne of the Electric Light Orchestra on "Rockline" hosted by Bob Coburn on 27 June 1983[5]. The subject is ELO's supposed use of backmasking on their song "Eldorado" from the album of the same name, and the controversy thereof. Though the vocals are occasionally difficult to understand when reversed, the following transcript is relatively complete:
(Interviewer's voice): "... to tell us about backwards masking ??? and the Electric Light Orchestra. A whole crowd of ... got all ... because they thought that if ... but, when it was hand-spun backwards on a turntable, and it said something like 'Christ is inferno'. Anyway, it was enough to ... cause some problems for ELO and Jeff Lynne in particular."
(Jeff Lynne's voice): "It is absolutely ...don't ask why I said that. It didn't say anything, anything of the sort. And uhm, that was total...in fact, it was a mistake, isn't it. Because anyone who can write a song played forwards and have it say something else backwards has got to be some kind of genius, and that I ain't! I was upset at first by the accusations, you know, but now, but now I would find them funny ... we're totally innocent of all those claims ... and we're all God-fearing chaps!"[6][7]
Original John Peel Broadcast ("Bad Day")
This version (sometimes referred to as "Bad Day") was recorded live for Boards of Canada's Peel Session on July 21st 1998. It differs from the studio version in a number of ways including a different outro, and has a generally rougher sound compared to the studio version. It also lacks the backmasked Jeff Lynne interview sample present in the studio version. When Boards of Canada released the Peel Session EP in 1999, the original broadcast version of Happy Cycling was replaced by the studio version, allegedly due to Boards of Canada being dissatisfied with their performance of the track, hence the nickname "Bad Day". Although it has never been officially released it is widely available online.
Live @ Warp10
Boards of Canada performed Happy Cycling live during their performance at Warp's 10th anniversary party on November 5th 1999. This version differs somewhat from the other versions, but for the most part is just a more polished performance of the version broadcast on John Peel, although the intro is different, starting with the droning choir sample on its own before the drums enter.
Live @ ATP
Happy Cycling was also performed live by Boards of Canada during their set at the All Tomorrow's Parties festival on April 7th 2001. This version differs substantially from the other versions. While it starts similarly to the Live @ Warp10 version, the second half of the ATP version is structured differently, with the bassline for the second part entering 16 bars before the main synth melody does. The main melody also uses a different synth lead sound to all other versions.