Noob Question on bottom bracket...or changing to one
 

My 12-year old daughter found a nice blue 1982 (I think) Murray bike she wants me to fix up for her. Frame in great shape, but wheelsets are trashed as is the one-piece crank. I have never done anything other than fix up a bike without changing parts, but now I have no choice (and it's time to learn anyway). Is it possible to switch over to a bottom bracket from the one-piece crank? Thanks for any and all help.

I believe you will need an ashtabula adapter if you want a 3 piece crank. If you need a wheelset and a crank, it might be more cost-efficient to get a cheap (higher quality) used bike on craigslist, but I know this isn't always possible.

I've thought about that as well. Fortunately, we have a bike "recycle" shop here that has some nice 26-inch wheelsets....but none has a coaster brake.......so, was wondering about switching the crankset over...

I can't say for sure, but I Think there are aluminum 3pc cranks for that style bottom bracket made for BMX bikes(from the 90s?). Maybe something to look into. Otherwise, as Puget Pounder said, you'll need the adapter.

Wow, a one piece that's trashed? I'd like to see a pic! The one thing that can be said about a one-piece crank is their resiliency (and weight, of course). I've seen a sprocket taco but the cranks are usually so tough!

it is trashed because of the rust. Something got on the sprocket and crank arm on that side and just ate it up.

Lots of bike shops have one or two ashtabula cranks lying around "in the back," which is the best place to be in a bike shop.
I'd check there.

I can't make sense of post #3.

That's for sure.......

here are some choices:

http://www.amazon.com/Truvativ-00-64...1973020&sr=1-1
http://www.amazon.com/BB-Conversion-...973020&sr=1-12
http://www.amazon.com/BB-Conversion-...im_sbs_sg_cy_5
http://www.amazon.com/Pyramid-Piece-...im_sbs_sg_cy_4
http://www.amazon.com/Aluminum-Botto...im_sbs_sg_cy_7
http://www.amazon.com/Dimension-Amer...m_sbs_sg_cy_17
http://www.amazon.com/Diamondback-Po...m_sbs_sg_cy_37

As I said, I am new to this. What I meant by Post #3 was that the wheelsets that the recycle shop has right now for the rear have cassette hubs which won't work with the current setup (I think). Hope that helps your understanding. If I am incorrect, I'd appreciate someone explaining my misunderstanding. thanks.

Errmmm not to rain on your parade, but more then likely converting the BB is gonna cost you more then the bike is worth realisticly... I'd probably see if I could find your daughter something similar with better components if I were you.

Ok Virginian, I'm gonna do my best to address what I believe you are asking here. If you're suggesting that the wheels you have your eyes on are a freewheel cassette build without a coaster brake, then that should have no influence on your crank/bb setup. If you are looking to switch from coaster brakes you'll need to set up a rim brake, and in order to do that you'll have to see if your frame will accept any type of brake. beyond that, the bottom bracket conversion has been addressed above, although I have to admit RaleighSport is probably correct about the cost issue. I Would stick with a one piece crank and talk to the guys at that recycle shop about some brakes that will go nicely with your frame and new wheels. I'll bet they've got more than their fair share of cranksets hanging around the shop.

Any reason you want a coaster brake? Have you thought about putting a 3-speed hub on it?