There are multiple pauses causes to wrist pain. Two I would check into are grip angle and holding on too hard. Check the alignment angle of your forearm and hand. If there is a twist here as you line up on the bike, I can see that would be cause for pain, particularly if you are "locking out" your elbows. I always try to maintain some bend in the elbow to grant relief to my wrists. I also use a Throttlemeister to allow me to let go of the right grip and flex the wrist and hand on long runs. I don't have my IBA, but I do have a couple of 500 mile days to my credit. Hope this helps.