This is my crank specs I found online.

Prowheel Alloy 335P6 28X38X48 170mm



I have the denali road bike and after
1600 miles the crank bearings are going out.

I want to order new bearings now to have them ready when the old ones get to loose to use.

Can anyone here tell what bearings I need? I dont have a lot of knowledge with bike parts. Thanks.