How to change bottom bracket or crank on my bike?

[edward w]

You will be best served by NOT doing anything to a Huffy bike such as this one. Most likely you will not be able to do much to this in the way of upgrading for less than $70! A crank alone would cost you nearly double that anyway! Let alone the rear derailleur likely does not have a mount that isnt a bolt on anyway (newer and upgraded rear derailleurs do not use a "bolt on" attachment). Rear Derailleur would cost about $25 just for Alivio to go 7or 8 speed. Huffy is essentially Junk and should be treated as such. You will in time realize this and let this one go in favor of nearly anything else you end up getting. You will also need a chain, new cassette, likely a rear wheel, crank, rear deraileur, and shifters. Even for the cheap components that you want to upgrade too you will still be well over the $300 mark to do it. Any bike shop will give advise for free- NOT labor! If you cant do any or all of this work yourself then expect another $150 or so just in labor. Now is that $70 Huffy really worth the expense?.....NO

 

[Rocky]

Hi , i have a cheap mountain bike, its a mens huffy tundra, it was my first bike and broke down after just 2 months of buying it! due to the cheap components, i didnt know much about bike but now im getting into it and its quite fun! i then purchased a team raleigh, it was beat up, but i fix it, (yey!!) i painted it and even did some custom designs, came out nice, anyway back to huffy, i dont want to get rid of it since it was my first bike and i really like the shape of the frame.
I need to replace the cheap components for better ones but dont want to waste more than the bike cost me ($70) So, how do i measure the crank size or bottom bracket to replace it? Also its an 18 speed, (6 rows in back and 3 on crank) if i just replace the crank for the one with 2 rows it will make it a 12 speed but whould that actually work?
Thanks for any help!!

 

[Nico]

Gear systems come in sets with dérailleurs and gears. You have to replace the whole lot as a set. They are not inter-compatible because of alignment.

Are you talking about Pedal crank? Just take it along to a bike shop and let them tell you whats what. It sure beats the guessing game and they most likely wont ask for money just to pass on some of their expertise.