Need Advice in picking a bike

actually, for one thing, when a bike's size is being described, such as 20", 24", or 26", it is describing the wheel diameter, not the frame size itself. a 17" bike is too small for an adult. an adult bmx bike is 20", so a 17" bike would be smaller than that. a boy's bike is 16". you can probably fit a 26" bike if you put the seat all the way down. go to walmart, pull a mens 26" bike off the rack, put the seat down, and try to sit on it. its easy to do, look under the seat for a quick release lever, release it, and push the seat down. you may have to wiggle the seat to get it to go down. as long as you can reach the pedals, youre good. also, unless you are buying a shift kit, which i wouldnt recommend for a beginner, it doesnt matter if its a mountain bike or a beach cruiser. the engine does not use the bikes gears. if using a shift kit, the engine does use the bikes gears, but shift kits are very expensive. it costs more than the engine kit does. i personally use beach cruisers, which are 26" single speeds, for all my bikes. my advice, as new as you are and as little as you know about bikes, i would keep this project as simple as possible.

Let me add my own personal piece of advice here. I love the beach cruiser bikes, and have built a mountain bike as well. A few things to consider as a first time builder.

Your average single speed cruiser has 1 brake, the coaster. This not only needs to be modded to fit the rear sprocket, it also has no freewheeling. So when you come to a stop, if your pedals are straight up and down, you have to roll the bike forward or backward to get the peddles level to start the bike again.

Personally I like the 7 speed cruisers for first time builders. Comes with both front and rear brakes, no coaster brake to modify. And while you may not be using a shift kit, a multi speed can really stand out. And it has the freewheel so you can spin the peddles backwards to get ready to take off again.

Again, this is just my opinion. Buy the bike that you like, look up the needed mods to get it running safely and go for it.

This is just my opinion, subject to change. Unless you're going to be peddling a lot, multi gears aren't necessary. Even with no gears your bike will go 25-30 mph, which is plenty fast for the majority of bicycles. Of course having gears doesn't hurt anything, so it's not a big concern one way of the other for a MB.

The hub adapters from Pirate Cycle work very well, and that's a good reason to have a coaster brake. Now there's sizes to fit some single speed, and 3 speed hubs. What comes stock in the kits works ok, but not as easy to install. Even if you're not planning to use one at first, it's something to keep in mind for the future when picking a bike to buy.

Most people don't set up their MB the same way they set up a riding bicycle. Usually the seat is set too low for best peddling on a MB, because we don't peddle that much unless you ride off road a lot. Having the seat low looks better, especially on a beach cruiser. Because of this you can probably get away with the smallest frame you can fit the motor kit in. Probably about a 17" frame would be the smallest.

Probably the best advise is ask the forum.

Plan on going through a initial period of high maintenance, and working out some bugs soon after you get up and running. Especially keep a close eye on the rear wheel bearing end play. Be sure and keep all your bearings well lubed and adjusted. This is necessary because of the higher speeds and forces on all the components.

A 17 inch frame (not wheel size) is gonna be a shade to big for you if you are 5 foot 4 inches....I am 5 ft 10 inches and ride a 19 inch frame (with 29'' wheels) you are probably going to fit a 15 inch frame (with 26 inch wheels)

Your problem is going to be fitting an engine in the space a 15 inch provides in the front triangle.

When it comes to mounting a China Girl motor on a bicycle, different size, and types of frames make a big difference in how difficult it's going to be.

What I've noticed is pretty much any frame 18" or bigger will fit.

Most beach cruisers have frames that are pretty easy to work with. If it's a mountain bike style frame, smaller than a 18" may be a challange. Even some 18's. A beach cruiser probably not.

All bicycles come with brakes. The ones you can't see any on, have a coaster brake. That's the kind where you push back on the peddles to apply the brake. I'm tempted to say a coaster brake is all you need if you're a good rider, but if you're not, you won't be safe no matter how many brakes you have.

Here's an example of what I talking about with frames. See how big the Atomic BB's 18 1/2" frame looks compared to my new 17" frame on my Caddy. It's not as much the 1 1/2" difference in the seat post height, as it is the shape of the front down tube.