http://www.chainreactioncycles.com/Kits.aspx?ModelID=17573 My current crank length is 175mm should I keep the same length when I order my upgrade? or is there any benefit from changing. The bottom bracket has two lengths, do I just measure where the bottom bracket goes? (what ever it is called) also the front mech do I just measure the width of the seat tube? I have to order it this week as the 10% off ends Thanks for your help.