I need to true my wheels on both my MTB and Road bikes. What I need to know is what size spoke wrench to get and how is it that you determine this? I didn't look to see if there are any markings anywhere on the nipples, or do I literally need to use a caliper to measure them?I had my wheels built-up at the LBS using DT Swiss Spoke, DT 4.1 hoops and CK hubs. My road bike has the stock Bontrager Race-X Lite Wheels... I have done a bunch of searches, but nobody has addressed this based on the different searches I have done.I need to get a spoke wrench, have the Ultimate Truing stand on the way and want to have the proper spoke wrench in hand when it arrives.Thanks.