Hi, I've been having problems with the crank of my bike. Last year, while riding it became very stiff to peddle, it got worse over time and now I cannot even use it because it feels like you are trying to go up a really steep hill when you are riding on flat land. We believe that the bearings need replacing, however is this a part that can be replaced or does the whole crank need to be replaced? We can get the tool from our friend to actually pull the crank apart, however I'm wondering if it would be best just to replace the crank its self. If any one has any suggestions or ideas that would be great, thanks.