You only really need 1 speed. Fixies are popular for a reason (well, they are also hipster, but there is still a reason for the initial popularity ;-) ). Espe

You only really need 1 speed. Fixies are popular for a reason (well, they are also hipster, but there is still a reason for the initial popularity ;-) ). Especially with a direct drive train, you've got a lot more control. However, our human muscles are most efficient using specific amounts of force and using specific cadences. If you push on the pedals too hard, then you start going anaerobic and build up lactic acid in the muscles. You can't sustain it for long periods. Similarly if you push too little, you have to spin the pedals incredibly fast to maintain speed. This uses up a lot of energy. The idea of the gear is to pick one so that you can settle into a rhythm where you are using the same amount of force that you normally do and you use the same cadence that you normally do. This way, no matter what the terrain, wind, etc, you can be as efficient as possible merely by changing the speed that you are travelling. Normally when I'm riding, I'll use a combination of 4-5 gears. Which gears I use depends entirely on the terrain and the wind. If I'm going up steep hills, then I'll be using the easy gears. If I'm on flats, I'll be switching around trying to find a comfortable gear depending on the force and direction of the wind. Honestly, you don't need 30 gears (and IMHO, if you don't have a lot of money it's better to spend money getting an overall good bike, than trying to get a couple of extra gears). I particularly like having only 2 chain rings (and I could easily get away with 1) because on cheaper bikes, it's easier to keep the derailleurs set up nicely (on expensive bikes, I don't think it matters much). However, I've got some hills with over 20% gradients, so I need some low gears. Having that extra chain ring can mean being able to get over the hill or not. If you are riding a lot (like several hours a day), having more gears is nice because you can always find a "perfect" gear for the conditions. This really reduces the amount of fatigue you experience. Again, it's the difference between riding 100 km and being relatively OK afterwards vs riding 100 km and being shattered. So if you are riding short times for leisure and the terrain is relatively flat (for example, nothing over 10% gradient), then you can save a lot of money to have a bike with less gears. But if you are riding a lot, in challenging conditions, then having a couple of extra gears can make a really big difference. One thing I should point out is that group set manufacturers are pushing higher numbers of gears into their lower priced offerings. This is because the engineering for those lower priced offerings is improving pretty significantly over time. Some of the cheap gear systems you can buy these days are almost as nice as the pro gear systems you would buy 10 or 15 years ago. The precision is good enough that there is no real reason not to have the extra gears. You might not need them, but if you start cycling in more challenging conditions, you will appreciate them.