Re:Woman Rides Bicycle to 183.9 MPH, a New World Record
by antongribok on Tuesday September 18, 2018 @09:21PM
(#18020894)
If the gears are 62:12 twice, would it be correct to say the final ratio is equivalent to 31:3?
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Re:Woman Rides Bicycle to 183.9 MPH, a New World Record
by schoen on Tuesday September 18, 2018 @09:29PM
(#18020931)
No, when you put gear ratios in series, they'll multiply rather than adding, so it's rather equivalent to 3844:144, or in least terms 961:36.
Re:Woman Rides Bicycle to 183.9 MPH, a New World Record
by userbinator on Tuesday September 18, 2018 @09:52PM
(#18021030)
More simply, it's a ratio of ~26.7:1 --- the wheel turns approximately 26.7 times for each turn of the crank.
Using some of the other numbers mentioned here, we can calculate that at her top speed of 296km/h she was pedaling at ~126RPM, and the wheels of the bike spinning at ~3377RPM.
If we knew the torque, or alternately the "stroke" of the crank and the average force she was exerting, we would also be able to find out her power output in W or HP.
Edit: some searching around reveals that 120-130RPM is usually where peak power is for cyclists, which corresponds with roughly where she was at top speed: https://www.ncbi.nlm.nih.gov/pubmed/17562069
...and it makes me wonder if she had another gear, would she be able to keep accelerating beyond that. She would've probably been producing 1-2HP at that speed.