How do I fix my bike? The middle of the bike where u pedal is all loose. How do i retighten it?

its where the chains go through......the front part... the middle axle thing is completely loose.

my question is how to do it... not what shud i do... haha and i bought this bike 2 weeks ago... im not gonna go buy another one... and i cant exchange it. final sale.

What you need to do depends on what's wrong with it. Yeah, I know, it's loose. But is it loose because a bearing cup has backed itself out? Or maybe it's because the bearings are shot? Maybe the axle broke. Can you turn both pedals in opposite directions at the same time? That would be a tip off. Do you have a single piece crank? Cottered cranks? Cotterless? They all come apart and out in different ways.

If the cups have backed out, just tear it down, inspect the bearings, and if they're OK, pack 'em with grease (no oil, jeez Louise) and put some Loc-Tite on the cup threads when you put it back together. If it needs new bearings, get some, and maybe a new axle if the race is worn. If your cottered cranks are loose between the two crank arms, you probably just need new pins. Happens all the time.

If you have no idea what I'm talking about, and you have a digital camera, send me an e-mail through Yahoo, and I'll give you an e-mail you can send me some pics to.

If your bike is old (been used a lot) or cheap then it is the bottom bracket (the bearings around the axle that the pedals connect to) is worn.

It's not expensive to replace the bearings but you need to remove the crankshaft to get into the bearing case. Often u need a special tool to do that.

If you have the tools it's pretty easy and cheap to fix it though.

you need a cresent wrench and 3 in 1 oil.
here it is step by step real simple
1. look where the crank arm meets the frame, there should be a nut there, undo it, there should be some ball bearings in there (note: you may have to take the crank arm out to see them) put some oil on the bearings and tighten the nut back so its good and tight, make sure that the nut is on both sides is good and tight, if that didnt help you may need new crank bearings. http://images.google.com/imgres?imgurl=h...
here is a link to the best diagram i could find

if you are talking about a bicycle then you need to turn the large nut( it does not look like a nut bu ti do not have another term for it. the round thing closest to the center of the crank. turn that until it stops, make sure that the pedals can still turn easily. now tighten the other nut on that same axle, and lock it down. after that you should be dome.

try retightening it first then take it to a bike shop because you probably cant fix it.

buy a new bike