There are 2 front chainrings. One accepts the power from the jackshaft and the other drives the rear cassette. In theory you could use a front derailleur but there is no room to put it. So having said that you will have as many gears as your rear cassette. If you have a 6 speed rear cassette you will have a 6 speed bike. I know everyone gets excited thinking wow I will get a 10 speed rear cassette so I will have 10 gears, don't waste your money. In most 6, 7, 8, 9 speed cassette's the lowest gear and tallest gear are the same you just have more choices in between with more gears but in practice this is how it works. I have a 6 speed cassette. I start in 1st gear from a dead stop and then at about 15 mph I shift directly in to 3rd, at about 22 mph I shift directly into 5th and usually stay there at around 30 to 35. If I want to go a little faster or just cruise at 35 to 40 I will put it in 6th. So I am already bypassing some of the available variation with 6 speeds so to add 8 or 9 would just be overkill. I essentially ride it like a 3 speed, 1st, 3rd and 5th with an overdrive, 6th.