How to straighten your bicycle rim depends partly on how the rim got bent in the first place. Whether the rim was bent by some type of impact or caused by leverage,
you will need some basic tools to get started.
A block of wood
A regular hammer
A rubber hammer
A regular or bicycle tool set
A grill or trash can
# suppose your bicucle rim was Bent by Impact:-
Bending from impact is typically caused by hitting something or from a hard landing after a jump.
If the wheel is uneven or out of round, it was likely caused by impact. For a wheel that was bent from impact damage, you can also use impact to fix it.
Check for bent or loose spokes first. If there are bent spokes, the damage is probably from leverage, not impact. If any spokes are loose, tighten them.
Then, remove the tire and tube. Set the wheel flat on top of the grill or trash can so that the rim lies directly on the top edge.
Next, place the block of wood over the center. With the high side of the wheel facing up, hit the block of wood with the hammer.
You might need to smack the wood a few times to get the wheel close to normal. Do use caution, as the wheel will bounce as if spring loaded.