How do you refer to a gear ratio?

Discussion in 'The Bike Cafe' started by Returning_cyclist, May 13, 2020.

  1. Returning_cyclist

    Returning_cyclist New Member

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    Back in the day, my old road bike had 27" wheels. If I was riding in a gear that was 44 on the chainring, and 22 on the cassette (2:1) I would refer to that as a 54" gear, and everyone seemed to know what I was talking about. How is that referred to now?

    Thanks!

    Don
     
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  2. Mr. Beanz

    Mr. Beanz Well-Known Member

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    I have heard gears called 1:1 but have no idea what it means and I'd probably never use the term myself so I don't worry about it. :p

    I use the front and rear combo calling it my 39 14 (39/14).

    I rarely use my 53 so I don't get too confused. :D
     
  3. dabac

    dabac Well-Known Member

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    You were doing ”gear inches”, a method that includes wheel size with gear ratio. It’s still in use. I have no opinion about how common or popular it is.
    Other options are ”meters development” or ”mph vs cadence”. The latter is my preferred method. It also includes wheel size and lets you know how fast you’d go for a set cadence at each gear. I find that the easiest reference for comparing different bike set-ups.
     
  4. dabac

    dabac Well-Known Member

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    That’s when you have the same number of teeth on the chainring as on the sprocket. One turn of the wheel for each turn of the crank.
    39/14=2.78.
    Written as 1:2.78.
    Meaning you get 2.78 turns of the rear wheel for each turn of the cranks.
    Giving the tooth counts is easier for the talker, but may require some math from the listener. And won’t work at all for IGHs.
    Doing the math first gives a more universally comparable number:
     
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  5. Mr. Beanz

    Mr. Beanz Well-Known Member

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    Ah cool! See, I never knew that, 2.78 turns of the wheel for each turn of the cranks. I see what that means now. But really, that never mattered to me and never even thought about things that way.

    Heck, I had a cadence meter in the past. Found I had a high cadence, about 95 rpm. Even that was interesting for about a week. Then after that, I never even looked at my cadence at all. I just know it's high enough to be efficient.

    Maybe the turns of the wheel for each turn of the cranks is important to the touring types? I've heard them talk about 1:1 set ups before. But I know in my case, the ratio of wheel rotation count to pedal rotation would never even enter my mind to interest me. :p

    Thanks for the explanation. Now when they say 1:1, I will know what they're talking about. :cool:

    I have heard of gear inches and paid attention to it 20+ years ago when I started doing major climbing rides. If I remember correctly, doing mountain climbs with 10,000 ft gain using 39 gear inches according to the gear charts. 39/26 = 39.45 gear inches. Once I knew that, I was set. I think I have looked at a gear inch calculator maybe 5 times in the last 20 years. And one more today though I knew it was 39 gear inches.
     
    #5 Mr. Beanz, May 14, 2020
    Last edited: May 14, 2020
  6. dabac

    dabac Well-Known Member

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    Well, the actual mechanics does matter to you, even if you don’t think about it. On a 1:1 ratio, even riding around the block would be tediously slow.(and the reason for the invention of the Penny-Farthing bicycle). On a 1:10 ratio and 700C wheels, you’d struggle even to get going. If it truly didn’t matter, you’d be entirely content staying in one randomly chosen gear all the time.
    But sure, the main use is for comparison. Once you have a bicycle you’re happy with, and isn’t planning to switch, this can be entirely ignored.
    Most of my body considers itself a masher - low cadence, low gear, high effort. That was all fine and well until the knees registered an another opinion and submitted their veto to further riding. Took me years to recover and kinda-sorta retrain as a ”spinner” instead. And while I’m now fairly well settled on an average cadence that’s 10rpm higher than before, I tend to fall back onto old, bad habits when I get tired or distracted. A cadence meter helps to keep me riding right.

    It isn’t the number as such that’s important, it is to have a recognizable comparison point. Since human bodies don’t come with a registered grunt-o-meter that lets us compare how much effort something takes, we have to find other ways around If we want to be able to hold sensible conversations about what works for a certain ride.
    BITD before MTBs, 1:1 gearing was as low as you could get on a stock bike, and quite important as such for loaded touring.
    But sure, gear inches, or meters development, or mph at a set cadence would all work equally well. It’s all down to the same thing, establishing a recognizable comparison point or frame of reference.
     
  7. ACyclingRooster

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    Hi to you all out there. I am a 74+ years young veteran that has sadly just given up cycling because of quite severe arthritis in my right knee and my right shoulder. The left knee was very successfully replaced in November 2007 and the right knee is pending because of the current Covid-19 situation.

    This website link below is the one that I have been using for some past 15 years and provides a great-deal of information and especially in gear inches which before modern technology was calculated with a pencil and paper.
    These are the last two bikes that I very very sadly sold,both were 50cm frames and both on Campagnolo 10spd + Stronglight Triples and both with Marcel Berthet Lyotard Platform Pedals and Christophe toe clips.
    DSCF3978.JPG DSCF4337.JPG
    http://www.jbarrm.com/cycal/cycal.html
     
  8. Froze

    Froze Well-Known Member

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    HAHA,as much as I like to cycle I just don't get into what gear inch I'm using; I know, I'm weird! I also don't talk about how many teeth I'm currently using...though currently I'm using 28 teeth since a long while back I had 4 molars removed...

    I just tell people I'm in 8th gear, or whatever gear I'm in at the time.
     
  9. Billy Dean

    Billy Dean New Member

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    When I first started cycling, I made a gear ratio diagram to help me figure out the relationship between gears on the large and small chain rings and between the gears on the cassette. It's all intuitive to me now because my fingers just "know" what my legs are telling them, so I don't use the chart any longer. But some of you might find it useful, or...?
    Scott Gear Ratios.jpeg
     
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  10. Mr. Beanz

    Mr. Beanz Well-Known Member

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    I did get a gear inch chart in a bicycling magazine on the back of a little training booklet given as a free gift with subscription to the magazine. That was when mags were in, pre internet days. Back in 1997 or so.

    I started climbing mountains with a gear inch of 39. Not knowing the 1:1 type lingo, I just knew I could make it up the mountains in a 39 gear inch combo. It was a matrix type thing, match the 39 ring with the 25 cog. Of course I had a 25 then later a 26 rear cog. Haven't looked them up in a while so not sure if it was the 25 or the 26 cog than gave the 39. Not even important after years of using the same gearing give or take 1 tooth on the rear cog. Whatever is affordable at the time, Shimano or Sram.
     
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