Is there any practical use for a 75-tooth chainring?

Question

I watched a video regarding a 75 tooth chainring and i was left wondering whether would there be any practical use for a chainring that big in size?

Answer 1

It is exaggerated to say that a cyclist can regularly use a chainring with a ratio of 75-tooths. Perhaps such a case could occur, but, for normal cycling, it is not reasonable to consider. High drag forces at over medium cycling speeds make the use of large gears self-defeating, and it is more useful to supply an adequate number of gears to allow comfortable pedaling at any point in the landscape.

Comments

Being a fixed gear guy,  there's absolutely nothing where it would work for me...  Knew someone that once tried riding the John Howard land speed bike, on a trainer, at a trade show.  He said it was absolutely awful getting the cranks turning.

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I can imagine that the chainring might suit a single speed/fixed gear providing you also increase your sprocket size - a 50/16 up to 75/24 - same gear inches but less tight articulation thus saving watts. It would look bonkers though. Or maybe it is used on a recumbent which due to much lower drag can require bigger gears.

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I've done more than 80kph pedalling with a 52-12 (downhill, of course!). Souplesse is the key to going quick. ;)

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It's great for a pedal boat where u need the extra RPM for the prop! :)

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I would love to see them do this again but paired with Shimano’s gravel cassette and derailleur, or better still on a bike with Drivelines 75 tooth chainring, paired up with SRAMs AXS shifters up front and Eagle AXS rear derailleur and cassette, to give a 50-10 rear cassette (assuming they were compatible - I confess I’ve not looked at the compatibility with the chainring and SRAM).
See Ollie’s match stick legs power up that hill with a bigger bailout gear!