cuzzinit

can someone point me to where i can read about bike gear sizes ? thx Cuz

Jim Kukula

Sheldon Brown is always a good place to start:

https://sheldonbrown.com/gloss_g.html#gear

or wikipedia:

https://en.wikipedia.org/wiki/Bicycle_gearing

wahoonc

I will second Sheldon Brown. What specifically do you want to know? Gearing is a huge topic. I use different gearing ranges for different types of bikes. Different bikes have different numbers and ranges. I have everything from single speeds up to 21 gears, new bikes can have as many as 28 or 30.

Aaron

cuzzinit

looking to get a folding bike, one of them is geared from 33 to 66.... i'm wondering how that will work for me. i read the wikipedia link and wonder if 66 isn't high enough. But i guess that can be remedied

Jim Kukula

33 to 66 is not a very deluxe gear range but it sounds practical actually in a bare bones sort of way. 66 ought to be fine for riding on the flat and 33 is decent for going up hills. You won't have anything for downhill but that is the least important gear anyway. Mostly I like a good downhill gear so I can pick up some momentum to help carry me a ways up the next climb!

If the price is right, a 33 to 66 gearing will get you across town OK.

sreten

Hi,

I'm an old duffer riding a 33 to 66 folding bike and can tell you
66 isn't enough for pounding downhill or for a big tailwind.

I also have a 40 to 100 road bike for comparison.

If your young and fit 33 to 66 will be limiting. I've done 33mph on
my folder downhill with the wind behind me, but stopped pedaling
to any useful effect around 20mph, that is a high cadence for me.

For me the gearing range is about right, assuming you don't
want to hammer it downhill or with tailwinds. 18mph is about
my consistent limit mild downhills or some tailwind on the flat.

I can go quite a bit faster on my road bike, not that it matters.

Initially for me I struggled uphill and into headwinds with the
lower gears, but I'm an old duffer, and now they are fine.

rgds, sreten.

otis66

I used this "Gear calculator.
https://home.earthlink.net/~mike.sherman/shift.html

sreten

Hi,

FWIW I can go up hills easier on my 40" to 100" road bike
than I can on my 33" to 66" folder, gear inches don't tell
you everything about the effective gearing of a bike.

The gearing for a typical 6 speed cheap folder is low for
16" wheels and about right when used with 20" wheels.
Usually a 14, 16, 18, 21, 24 and 28 freewheel on the back.

rgds, sreten.

fietsbob

Ratio (tooth count numbers) F:R x wheel diameter, calculate circumference X wheel RPM & you got speed.

cuzzinit

Thx that's what i wanted to know

Retro Grouch 

You're asking a question that only you can answer.

None of us have to ride that particular bike over your roads while using your body. The bike comes with gears the manufacturer thinks will work for most people. You aren't most people, you're you. Get the bike and ride it around for awhile. It'll tell you if you need higher or lower gears.

sreten

Hi,

Not easily or cheaply. The rear 6 speed is pretty much a standard 14 to 28
freewheel, and the 14 to 34 megarange won't work with the rear derailleur,
though I assume your after more than 66", not lower than 33".

I've looked and haven't found many other sized 6 speed freewheels.
I'm sure they are out there but just not very common / stocked.
13t is the smallest I've found and not cheap at all.

Changing the crankset to more teeth is expensive for the minor benefit.

rgds, sreten.

cplager

If the bikes are tuned and fit the same way, it should tell most of the story. Admittedly, for many folding bikes this probably isn't the case.

That suggests that either your position on your folding bike isn't as good as that on your road bike (meaning you can more easily generate power on your road bike) or some other inefficiency in your folding bike (tires, drive chain). At hill climbing speeds, aerodynamics shouldn't be playing a large effect.

The real point of this is that this doesn't have to be the case with folding bicycles - they can be (almost) as performant as full size bicycles.


This is basically correct. Long-story-short, if you know you are going to want to change the gearing, you are probably better off buying a nicer folding bike.

martianone

IMHO - for a non racing utility and pleasure rider, a 1x9 set up bike with 12-36 cassette and 44 t chainring with a 32/622 tire provides a gear in range of 33-99 (in hilly areas substitute a 39 t chain ring). This range provides a pragmatic and reliable useful range.