Gearing Question

[nanac1212]

I like my adult single speed trykes geared at 36/22. With long arm 7.5 inch cranks its a comfortable easy to pedal pace. I just picked up an older heavier tryke and was wondering how 40/24 gearing would be compared to 36/22. With a 36/24 setup you would be spinning and not going anywhere.

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[deorman]

This might help: http://www.bikecalc.com/gear_inches

 

[nanac1212]

I dont understand all those charts and figures. All I want to know is if a 40/24 gear would provide an easy to pedal gear at a reasonable pace. Not spinning and traveling at a snails pace.

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[LukeTheJoker]

I like my adult single speed trykes geared at 36/22. With long arm 7.5 inch cranks its a comfortable easy to pedal pace. I just picked up an older heavier tryke and was wondering how 40/24 gearing would be compared to 36/22. With a 36/24 setup you would be spinning and not going anywhere.

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Assuming both trikes are 26" wheel versions, using that chart your 36/22 version comes out at 42.6 gear inches. 40/24 comes out at 43.3, fairly similar...

If you want to make it even easier, if both trikes or bikes have the same size tire, just divide you chainring by your rear sprocket:
36 / 22= 1.63636363
40 / 24= 1.66666666

Those figure are how many times the wheel will turn per crank revolution.

So the 40/24 will be ever so slightly higher geared than the 36/22, but I doubt you would even notice the difference.

Luke.

 

[horsefarmer]

FYI there is a cool calculator at:
http://kstoerz.com/gearcalc/compare/

And as a general reference,
Sport Touring Steep hills 27-37
Medium hills 32-42
Flat 37-47
Road Racing Steep hills 47-60
Flat to rolling 57-66
Mtn bike Steep hills 17-20
Technical trails 17-20
Dirt roads 20-27

Real world my 1955 Schwinn Tiger SA 3 speed middleweight.
Ratios are 0.75, 1.0, and 1.33 on a standard "wide-range" Sturmey hub. Typical sprocket selections yielded about 50, 66, and 88 gear inches. This is a pretty useful range of gears, but I usually stay out of high gear (too tall for this guy except downhill)

 

[nanac1212]

Sounds like 36/22 is my best option. Any lower youll be cranking your butt off and not moving.

I was just wondering if the 40/24 setup would give you more pedal leverage with the large rear freewheel and allow you to maintain a decent speed without spinning like crazy and still being quite easy to pedal.

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[nanac1212]

Sounds like 36/22 is my best option. Any lower youll be cranking your butt off and not moving.

I was just wondering if the 40/24 setup would give you more pedal leverage with the large rear freewheel and allow you to maintain a decent speed without spinning like crazy and still being quite easy to pedal.

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With a 36/24 you would be pedaling like a circus monkey.

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[Raoul Dude]

I dont understand all those charts and figures. All I want to know is if a 40/24 gear would provide an easy to pedal gear at a reasonable pace. Not spinning and traveling at a snails pace.

Those calculators can be really useful -- but you first have to put in the number of teeth on your chainrings and/or cogs, and the wheel size.

When you're only comparing TWO chainrings and two cogs, it makes for a lot smaller chart than the first one on that page, but for all those people with derailleurs that calculator wants to calculate all of the possibilities in that entire RANGE:



We'll just cross out the numbers we don't need, for those imaginary, in-between chainrings and cogs the calculator added, and we're left with four numbers. The 42.5 (from the 36x22 combination) and the 43.3 (from the 40x24) are pretty close to each other. If you turn the pedals at the same speed, the bicycle will actually be going slightly faster with the 43.3 gear inch combination.

The 38.9 gear inches from the 36x24 combination would be the slowest-moving bicycle of all, but if you REALLY want to see "monkey on a bicycle" pedaling that would be a normal mountain bike "granny gear" of 20 gear inches, or about half the speed of the 36x24!

 

[nanac1212]

Ok heres what I guess I am asking. If 3622 and 4024 are pretty close would the 4022 actually easier b3cause of the very large freewheel? 24t freewheels can be found on Ebay for less than 10 bucks shipped direct from overseas.

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[horsefarmer]

OK. Bigger sprocket on front (pedals) = harder to pedal.
Bigger sprocket on rear wheel or axle = easier to pedal
If tire and rim dia don't change.

 

[Raoul Dude]

Ok heres what I guess I am asking. If 3622 and 4024 are pretty close would the 4022 actually easier b3cause of the very large freewheel? 24t freewheels can be found on Ebay for less than 10 bucks shipped direct from overseas.

From a strictly mathematical, gear inches perspective, 40x22 is the highest of the four red numbers in my chart above, so it's going to be the HARDEST to pedal, especially starting the bicycle from a dead stop. If you can spin the pedals of all four chainring and cog combinations at the same speed, your bike will also go FASTEST with the highest red number.

Any mechanical advantage from a larger chainring (and more leverage) would probably be minimal, and a lot more complicated to figure out.

 

[nanac1212]

Thanks 3veryone for your input. Its been a good education. I do have one final question and I am done.

Tryke A geared 36/22 with 24 inch wheels
Tryke B geared 36/24 with 26 inch wheels.

Which one will travel slightly faster using the same crank rpms?

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[deorman]

In theory:
Trike A 40.6" travel per crank rev.
Trike B 38.3" travel per crank rev.
Trike A travels a hair over 2" further per revolution.
In real life:
Different tires will yield slightly different actual numbers.