Can you rephase your question? I was just confused on what you mean by bumps. Do you mean their durability and strength due to bumps and how they possibly might bend or dent? If thats the question, weight has nothing to do with tensile/compressive strength, yeild strength, etc. Some materials that are light are much stronger than heavier ones i.e. titanium. If you want to know strengths, go to matweb.com and click on material properties. From there you will know its strength and compare them to the material of the rims you have now. Hope that helps. =)