I have a 2010 ex5 that I have replaced most of the stock parts. Reba rlt ti fork, pure xcr wheels right around 1600 grams tires are lighter. Sram 990 cassette. I have coming a slx crank then x9 front and rear D's. My question is when I put the bike on my home scale it was 31 lbs. Stock crank. How is a ex 8 so much lighter. I have better wheels and fork and tires. Plus some other small upgrades bars and stem. Is the frame and shock pivot on the higher end models better and lighter. I am not a hugh WW but i was just curious.