I've seen it mentioned here a few times - those wriggly uncooperative B1 leads when they're new, and no posts about how to cure the problem.
Here's 3 suggestions:
1. Taking care to hold the speakon connectors, soak the rest of the cable into a bowl of very warm/hot (not boiling) water. DO NOT GET WATER INSIDE THE SPEAKON PLUGS. This will soften the cable up, lie the cable out flat and straight to dry. This will give it a "new memory" of sorts and be easier to maintain in the future.
2. Wrap the cable or lie it flat and straight and leave it on the footpath or driveway in the sun. Shouldn't take long.
3. Leave them wrapped in your car/van on a hot summer day. This is usually how I unintentionally fix all of my cable messes.