PRO vs BEGINNER CYCLIST What s the difference in SKILLS POWER and SPEED Wheel size 16 usually for age 5 to 9. Wheel size 26 Adult size. Trek alpha super light xl road bike shimano 105 groupset please do get in touch. This item is in the category Sporting Goods\Cycling\Bikes. Shimano 105 brake caliper, 105 sti shifters, 105 derailleurs (front & Rear), 105 cranks set.