: Id like to change pedals of my mountain bike, which type should I prefer?

Most likely the break pad is rubbing intermittently as it rolls because the rim is bent. If its a OEM spoke rim then it wont take many curb jumps to bendit. Most mountain bikes from a walmart or academy wont be anything more than the basic for streets. If you are going off road on real mountain biking trails then you would be better off getting a stronger rim but these can be pricey. Another cause can be that the tensioner springs near the break pads need to be adjusted so you can pull the pad away from the rim. Problem is that it will take some of the stopping power away. Not recommended. Most high end mountain bikes have an actual rotor type disc break like a motor cycle that's on the inner rim so that way even if the rim gets a little bent or wet, the performance of the breaks is still up to par. To check if your rims bent, turn the bike upside down and set it so you can spin the back wheel really fast with the pedals. Then look at the tired from directly behind it. If its bent, you will see the wobble.

Being a mtn bike it probably had flat pedals or lock-in SPD. Either way, pedals dont come in sizes, the shoes do. A pair of pedals will fit ANY bike, just select the type you want. Just be careful when screwing on, there is a LEFT PEDAL and a RIGHT PEDAL. They screw on in oppposite directions.!

I tried to find the user manual online but I can get one, I would suggest to visit your manufacturer's website for you to get one.

For replacing a pedal, you just need some tools like open grinch depending on the size of your pedal.

Thanks.

Hi michaelcook1....
Sounds like you need to adjust your derailer on the back of the bike, it may be out of adjustment and causing the chain to slip.
Please take time to rate me

If it is when you pedal, check the bottom bracket (where the cranks are attached) The bearings might need changing which would cause the noise.

Do the handlebars rock back and forward, if so, check and tightent the headset, check the bearings inside if they are dry or broken, replace and re-grease.

Be advised the left pedal is left-threaded. Get yourself a nice Park brand pedal wrench.

What fixing nut?

How to:

http://www.parktool.com/repair/readhowto.asp?id=83

If the pedal is moving too free,but the bike are still moiving forward, it simply mean you are using to low a gear .

Try changing to a high enough gear to satisfy your required tension. Be advised that,
You will also increase your speed,and decrease your hill climbing in the process though.

To change the front gear (probably 3 selections) use the left lever. To change the rear cassette, use the right one. To shift smoothly, slow your pedalling to switch, and don't change gears when you are pedalling hard, especially up hill. Gears hate that :)

im certain that model has a 3 piece crank set up. the inner crank bearing jam nut has loosened up or the bearings themselves have gone bad.first check to see if its tight, if it is then it will require a replacement set of bearing that are a pretty standard size to all bikes and can be purchased at nearly every bike shop.