Pedal faster and the lamp gets brighter: China's rural pedal cinemas, 1960s–1980s

A standardised format for villages without electricity

When China introduced the 8.75 mm film format for mobile rural projection around 1970–1971, villages that mountain electrification had not yet reached were served by purpose-built pedal generators adapted from bicycle frames and wired directly to the projector ¹. County records describe the equipment in ordinary administrative language. Qimen County, Anhui, records that the commune film team it established in 1970 used an 8.75 mm projector "配有脚踏式发电机" — equipped with a pedal generator — because mountain electrification had lagged behind ¹. Yichuan County, Shaanxi, records that from 1971 fourteen 8.75 mm projectors with pedal generators, donated in support of the Yan'an old revolutionary base area, formed fourteen commune film teams staffed by twenty-eight trained projectionists: "一个比较完整的电影放映网初步形成" — a relatively complete film-projection network initially took shape ².

Two riders, no buffer

The working experience survives in oral history rather than engineering documents. China News Service recorded Yunnan projectionist Li Shangting in 2018: "那时村里没通电，放电影前要发电，只有脚踏发电机，放映中要不停地用脚踩踏才能持续供电。'我们经常是两三个人轮换着用脚踩，踏上半个小时大汗淋漓，一场电影放下来浑身都湿透了。'" ("Back then the village had no electricity; before a screening you had to generate power — there were only pedal generators, and you had to tread continuously through the screening to keep the power on. 'We often had two or three people taking turns pedaling; after half an hour you'd be drenched in sweat, and by the end of a film you were soaked through.'") ⁹

Memoir sources describe the typical unit as a two-person, tandem-style frame with a 12 V / 100 W generator, a figure that rests on a single recollection rather than a measurement or an official specification ³. An industry history of Chinese film machinery records 300-watt supporting generators built alongside the 8.75 mm projectors; the two figures do not reconcile and may describe different generator classes ⁴. Every source, gazetteer and memoir alike, agrees on the architecture: direct drive, with no regulation and no buffer between the pedals and the lamp, so screen brightness tracked pedalling speed in front of the audience — "踩快点灯泡就亮些，踩慢就暗些", pedal faster and the lamp gets brighter, slower and it dims ⁵. A recollection from another province records the same effect on the screen: "有时候踩的慢了屏幕马上就暗了下来", sometimes when the pedalling slowed, the screen would immediately dim ⁶.

A 2016 laboratory measurement

The measured counterpart to that oral history is a 2016 peer-reviewed study in the Journal of Wuhan University (Engineering Science), motivated by pedal-powered open-air cinema ⁸. The Wuhan team instrumented a whole chain: a single-speed bicycle with a 660 mm rear wheel, belt-coupled to a 24 V brushed DC motor, charging a 12 V / 22 amp-hour lead-acid battery, feeding a CD4047-based inverter that stepped 12 V up to 230 V ⁸. They measured a generation efficiency of "around 58%" at a normal cadence of 60 to 70 revolutions per minute, charging to 95% of maximum voltage in about half an hour, and a full battery sustaining the projector for 45 minutes at an average draw of "around 58.2 watts" ⁸. It is the only peer-reviewed, fully measured pedal-cinema energy chain located in this corpus, and its per-rider figure lands within a few watts of the 50-to-60-watt constant that KLAK, Electric Pedals and CycleCinemaClub each arrived at independently.

What remains

A working unit from the original era survives at the Sichuan University of Media and Communications museum and was demonstrated in operation in December 2025, still driving an 8.75 mm projector more than fifty years after the format's introduction ⁷. Rural electrification erased the system class from the mid-1970s onward, and the surviving period photographs show the work around the light rather than the making of it: a film team carrying its equipment into the mountains, a lit screen at night, a projector on its case. The one period photograph of the apparatus itself located for this page — a county-archive image from Tongshan, Hubei, dated 1975 — catches it in transport: two projectionists climbing a path at dusk, the bicycle-frame generator on one man's back. The half-hour of mid-show pedalling, in the dark behind the audience, left no image.

The six-language search found no pedal-cinema provider, commercial or nonprofit, operating in Mainland China, Taiwan or Hong Kong; the modern Chinese 发电单车 (generating-bicycle) industry builds interactive lights, fountains and phone-charging carts, not cinema ¹⁰.