Just upgraded from a 7 speed Schwinn cruiser to a KHS Urban-X commuter bike with 21 gears... I'm at a loss.. why all the gears? I have two pretty good hills to scale each ride home in the evening. It was hard on the cruiser, but I got it down to 1 stop after several weeks of keeping at it and building my muscles up. Now that I have so many gears? First time this evening on my new bike I rode up the hills and yes, going to a lower gear makes it easier to peddle, but you slow down so much and peddle so fast you end up just as winded as when peddling with the limited low gear on the 7 speed. Am I doing something wrong? I put the front three gear choice in 3 (smallest cog) and was peddling with the back in combinations of 3-5 gear coggs.
Years ago I had a raceing bike with 10 speeds and always felt that was enough to get me anywhere I wanted to go. Are 21 gears over kill?

Slow down. If you are pedaling so fast that you are winded at the top then you are not using your gears efficiently. As an experiment, try the same hill in your lowest gear but only go as fast as the bike will take you doing about 80-90 rotations of the pedals per minute.

Hills come in different heights and steepness, some riders carry a lot of stuff.
This is why some bikes have 21 even up to 30 gears.

I've got three bikes. One's a commuter with 21 gears, one's a road bike with 20 gears, and one's a mountain bike with one gear.

For commuting the 21 gears come in handy. Biking around town, I don't ever use my lowest chainring (22). I usually keep it in the middle (32) unless I'm on a flat road long enough to get up to speed, then I'll switch to the largest chainring (44). The middle chainring + the 7 gears in the back would be enough to get around. However, I like having the big chainring to go even faster while keeping the same pedaling speed (cadence).

I have to use my smallest chainring (22) when I'm biking up the hill I live on. It averages 10% in grade for a third of a mile.

For the road bike, it's obvious why there are so many gears. Your speed will vary a lot while climbing to descending. Road biking is all about efficiency by keeping the same cadence using your gears.

I'm not sure why I chose a SS mountain bike. I think it makes more sense than a SS commuter or road bike (unless it's flat). The gearing on the mountain bike is low enough for steep climbs and/or long climbs. It's high enough for me to spin up to a decent pace, unless it's a nice flat smooth trail. Once I hit a certain speed going downhill (near my gearing limit) pedaling will only make a small difference.

First, keep in mind that there's a difference between the number of gears and the range of the gears. One doesn't necessarily have anything to do with the other. Your 7 speed could theoretically have as much range as the 21 speed (though admittedly, that's very unlikely). It could also theoretically have a lower lowest gear or a higher highest gear (again, very unlikely).

The purpose for having larger numbers of gears is to allow the rider to maintain a more consistent and optimal cadence as much as possible.

The purpose of having a larger range is to allow pedaling up and down steeper hills.

Second, climbing at high cadences is a skill that you sort of have to learn. It is certainly possible to be in too low of a gear and spin too fast and move too slow. Given the fact that you've been climbing for a long time in higher gears, it would not surprise me if your pedaling stroke is not smooth enough to be at its most efficient at a high cadence. You just aren't used to it (yet). You've also built up enough strength to climb in that higher gear. Congratulations that your knees can handle that (mine can't).

You should probably up your gear a bit to find an optimal compromise for you. Getting optimal efficiency from a high cadence requires a smooth pedaling stroke. If you're not smooth, the high cadence will not help nearly as much, possibly not at all, possibly even make it worse.

You might want to figure out what your old gears were and what your new gears are and try climbing that hill in a gear that's just a little bit lower than your old lowest gear and see what happens. Next time try it just a bit lower than that. Keep doing it until you figure out the optimal gear for you.

Here are some useful links for that:

https://www.sheldonbrown.com/gain.html

https://www.sheldonbrown.com/gears/

I stay on the middle rings of both my 24 and 21-speed bikes. The granny gears on the rear sprockets of both are enough to climb any local hills, and while I have used the smallest front ring when hauling my son and the largest when pedaling down hills, I could live with just the middle one. My latest bike has an Alfine 8-speed IGH and it's got all the range that I need. That being said there is a gap between 5th and 6th that is too wide for my liking. I would definitely like to retrofit the bike with the soon-to-be-released Alfine 11, but the cost is prohibitive.

There will always be a market for more gearing than a rear sprocket (even a 10-speed one) can provide, but for my commuting needs 7 or 8 gears is fine. One could even add a compact double crankset and front derailleur to a chain-driven IGH bike, thereby doubling its number of gears. This, however, is not an option on my belt-driven Norco.

A 7x3 transmission has about 11 usable gears. There is a lot of overlap in the gear ratios of the 3 front chainrings. With a 7-speed system, all the gears are usable.
You use gears to maintain a constant power output and pedalling force and match that output to the terrain. If you are spinning too fast on a hill, you are in too low a gear.
Try and ride at a steady pace with a rapid pedalling cadence and a constant pedalling force, changing gears whenever you feel the need. Of course you have to alter things a bit on hills but you should aim for a smooth riding style.

Do you mean you put the left shifter in the 3 position? On the front that would be the largest cog. If it was the smallest cog, that's mainly for steep hills and/or heavy loaded climbs. You should be able to get around fine on the middle chainring in front, using all 7 in the back. If you need a higher or lower gear than the rear can provide, change up or down at the front.

+1.

Think of usable gears in terms of how much effort you spend to travel a certain distance. If one turn of the crank moves your bike 25 inches, that's a very easy or low gear, if one turn moves your bike 100 inches, that's a very hard or high gear. The reason to have so many gears is the spacing between those 2 numbers. Some people go as low as 20 inches to climb hills loaded. Roadies like 110 inches plus to sprint.

Then there's the question of overlap and spacing. A good spacing is 15% between gears, but many gears overlap on a 3 ring crank as was mentioned, so you end with fewer actual "steps". You also want to avoid too steep a chain angle to avoid chain wear - smallest front ring to largest rear cog and viceversa. This is why internally geared hubs are so appealing. A single chain ring, single chain line and all usable gears in the back, one after the other, without having to chase the different combos. Look up Rohloff hubs on Google to see the ultimate in gearing - 14 serial gears without duplicates!

I have 27 (triple on front, nine on rear). I actually use the entire range of gears on every commute. I ride up switchbacks in the lowest gear and down steep hills, where I spin out at around 32 mph in the highest gear.

The appropriate gearing depends on your terrain, fitness and riding style (mashing vs. spinning). Some riders use only a single speed for fairly flat commutes. The more gears you have, the greater the range of gears and the smaller the steps between gears.

Keep in mind that due to cross chaining, the full range of gears is not really useable, and there are some gear combinations that are duplicates. In reality, I probably have 18 unique combinations actually available out of the 27.

get a cadence meter, report back in three months.

It's 20 more than you need.

Move to idaho or wyoming and go on a ride in the mountians, bet you come back asking for even more gears

I just rode a century in the Adirondacks a few weeks ago on my touring bike. On some steep sections, I was using my lowest gear (26T chainring and 34T rear cog). I was creeping along, but I kept a good cadence and wasn't walking. On some downhills, I was in my top gear (46T chainring and 11T rear cog). I have 27 gears and used all of them at some point that day.

Gears give your bike versatility. You may only need one gear on some routes, but you'll be glad you have other gears on hills and when carrying stuff.

+1

Thanks for all the answers and comments. I've been riding with the front on the middle ring and using various rings in the back for most of the rides, even on hills. On Sunday, when I went up the coast bike trail, I found some others walking their bikes up some of the steep hills while I was still in that front middle gear and hadn't gone to the smaller one.. I would guess that the gearing was about the same as the 7 speed in it's lowest position with that setup. Going down some hills and in some flat clear areas having the bigger ring in front allowed me to get more speed and that was definitely a benefit over the 7 speed that wouldn't allow me to go very fast.

I'll experiment some more on the rides home, I was probably geared to low and peddling to fast like some of you mentioned. When I was a kid with my single speed Schwinn I could go up hills steeper then any of these standing on the peddles the whole way, non stop, but I was in a lot better shape and very lean.. I'm an old guy now! :~)
What's still a bit confusing is approaching a hill.. I guess one gets good at gaging what front ring they will need? On the trip home yesterday I got part way up the hill with the middle front ring and in the lowest back gears then decided to down shift to the inner, small front ring and was immediately in too low of a rear gear, then had to quickly up shift the rear gear because I was spinning way to fast. Maybe I didn't even really need to go into that low front gear? Or maybe I should have shifted to the small low front gear before getting up the hill and then used the back gears to shift down as I felt the need to?
Hope this is making sense.

"Cadence" ...good word and that makes sense. I noticed when I first started riding two months ago I was trying to force it too much and would then have to stop and rest. It wasn't until I learned to sort of only peddle with in the strength of my legs that I was finally able to get up the hills with out stopping. My muscles were getting stronger too, I realize that, but I kept wanting to over do it; learning to hold my self back to the strength of my legs for the gearing available was what worked. So, ya, maybe, unless I'm carrying a lot of weight, I don't even need those low gears? They just make it take much longer to get to the top of the hill and break down your stamina, even though it is easier to peddle?

So, maybe this all comes down to choosing the proper front ring, before you need it, then using the range of gears available in it for the task at hand. If I'm on a hill in the middle front ring I may only need that range with the 7 back ones, but I might have been better off shifting down to the smallest, lowest front gear before starting the hill so I would have the lower gears available if I did feel I need them?

+1. It's not about speed, it's about pedaling cadence. I'd even settle for a bike computer that only shows cadence and the time of day.

OP, don't bother choosing a gear combo that has you pedaling faster than a jogging pace.

I think I was 12 when I got my first multispeed bike. I wasn't even the first in my neighborhood, so to speak. You'll figure it out.

You're catching on. What I do when I change chainrings is also shift the rear about three cogs so I can keep close to the same cadence. That way I'm not suddenly spinning at 130 rpm when I approach a hill and downshift the front.

I tell newbies with triples to use the middle ring for cruising, big ring for speed, and small ring for climbing, then adjust the feel wih the rear.

i've a got a 53/39 chainring with an 11-28 10-spd cog for 20 different gear combinations on my road bike, with maybe 14 actual usefully different gear ratios, but because chicago is so remarkably and unceasingly flat, i'm almost always on my big chainring and i really only ever use 6 of the gear ratios depending solely on wind conditions.

53/28 (49.7) - bad chain alignment, i don't use it
53/24 (58.0) - bad chain alignment, i don't use it
53/21 (66.3) - strong headwind (also my starting gear)
53/19 (73.3) - fair head wind
53/17 (81.9) - light headwind/neutral
53/15 (92.9) - light tailwind/neutral
53/14 (99.5) - fair tailwind
53/13 (107.1) - strong tailwind
53/12 (116.1) - only for down hills, and living in chicago, i don't get to use it often
53/11 (126.6) - only for down hills, and living in chicago, i don't get to use it often


so for the most part, having 20 speeds is overkilll most of the time for me, but it is nice to have the 39t chainring to drop down onto when i'm traveling with the bike in places that actually have hills.

A lot of great posts in this thread. But I just wanted to comment on this one section of your original post. If you go up the hill at the same speed you're going to get as winded, gears (being passive mechanical devices) don't actually save you any energy

The benefit of lower gears is that they let you go slower, comfortably, without having to stand on the pedals. And you can go much slower... I can stand on the pedals, but there is a limit on how slow I can pedal before the bike falls over, I would need a fairly low gear to slow down to 2 mph...

Part of my job at "The Corporate AntiChrist" (Wal-Mart) is giving expert advice on the BSO's they sell there. Since I know none of the people who shop there will EVER spend 300+ on a bike, I tell them what they need to know without saying, "Go to a shop." I get the question frequently about 21 speeds ( the standard there) -- I'll frequently tell them that I have 27, and use about 4 (truth), but I'm glad to have all of them in case I get into something hairy and need them! (I'm just glad I don't get that question as often as the 900-and-counting tally of "Does this come in any other color?")

{NOTE: BSO= "Bike-Shaped Object"**

"BSO= 'Bike-Shaped Object'"

&...

BRSO="Bike Rider Shaped Object"

More gears come in handy in these situations:

1. Going uphill
2. Going downhill
3. Strong Headwind
4. Strong Tailwind
5. Carrying a bunch of stuff uphill

6. Trying to match your speed to somebody else's

Number 6 becomes important in group rides and races. More gear choices that are relatively close together help even when you're on mostly level ground.

So if your riding on windless flat roads carrying nothing but your clothes then a single speed bike may be the right thing for you. If not, you will eventually appreciated a variety.