Hey everyone!
After my MTB got stolen when I moved to Philadelphia, I decided that I'd get a three speed commuter bike, complete with fenders, rack, and basket. Well, I found all of this in a cheap little package at Performance Bikes: the 2010 Schwinn Coffee cruiser. It rides like velvet, its super cheap (came in at around 215$ after discounts and coupons so I won't be heartbroke if it gets stolen), and it comes with fenders, rack, and chain guard. The biggest issue is that it's a single speed. I tend to ride fast, and with the single speed I eventually hit a point where my cadence just isn't pushing me faster.

After research, I found out that they also released the same model with 3 speeds. What would be the process of converting from a single speed to a 3 speed? Is it possible? I've never really done any bike modding so this will be a first for me. I'm not looking for the ability to climb mountains or go scary fast, but I'd like a low and high gear (or high and higher) compared to what I have now.

Three speed wheel with the proper shifter is the basics. You can buy ready made wheels, or you could build up your own. There are several 3 speed hubs on the market at the moment. SRAM, Sturmey Archer and Shimano.

Aaron

Probably. Examine your bikes frame. Do you see any little fittings for routing the shift cable?

If you do, that's good. A new rear wheel and shifter will probably do you. Don't be surprised if you have to pay almost as much as you did for the whole bike.

If you don't, I'd recommend rethinking the whole conversion idea. No cable fittings says to me that the 3-speed has it's own frame. If that's the case you might encounter additional issues, like rear dropout spacing, to complicate the process.

Three speed?

Get an 8 speed! No one needs to ride on a 3 speed anymore!

just to be realistic, a 3 speed comes with 2 gear options ,
classic is 3/4 and 4/3 of the middle ratio.. .75 & 1.33
SRAM has a bit wider difference between gears 36% rather than 33%

but a 3 speed can be put in fairly narrow frames like track / single speed types.
some of the multispeed IG hubs are needing a wider axle to get it all in..

,, and do get a really good lock, so you don't have to do this again.

One option is to check out thrift stores. Just find an old 3-speed bike with the same wheel size and swap the parts over to your bike.

The simplest thing to do is to have a bike shop lace in a 3 sp (or 7/8 speed) into your wheel and change the front chain ring to a 36 tooth and ride the dickens outta that bike. I did this for my wife and she now rides her Schwinn girls bike all the time. (Tip: DON'T forget the front chain ring to make the gearing work better. )

wouldnt the simplest option be to get a triple crankset and FD?

My impression -- it's probably more trouble and expense than it's worth, unless you reeeally really like the bike. Especially if you have to add brakes & brake cable stops & other such bits.

I've done the conversion to 3 speed on a Schwinn Breeze. Expensive and cost lots of time trying to find the right bits and make it all fit. Didn't make sense as there are so many good old Schwinn Breezes that were mfd as 3 speeds out there, and they sell for very little. Why did I do it? Nostalgia. Was a relative's childhood bike now cleaned & fixed up for her children. Misplaced nostalgia perhaps, an original 3-speed would've been fine.

None of my bikes have braze on fittings for the three speed bits and parts. They are all clamp on and can be purchased in a sizes to fit a variety of tubing diameters.

To the OP, I would also look and see about maybe purchasing a Schwinn Coffee in the 3 speed version, probably wouldn't cost more than a $150 or so above the cost of getting a new wheel and getting it set up properly.

Aaron

The Sturmey Archer SRF3 is a nice hub and you can find them cheap. The shifter and other hardware comes with it.

Clamp on fittings are inexpensive and easy to find.

I've converted a couple of bikes to IGH. It's easy and worth it.

You would need a chain tensioner in the back to take up the slack when the smaller chain rings are used. Simplest would be just to go with one chain ring.

Ummm NO! Just use a shorter chain.......

No, it would not.......

While using a FD? Explain why a tensioner would not be necessary.

Maybe he means that each time you want to use a smaller chainring, you'd switch the chain out to a shorter chain.