It's interesting that Kirby was surprised when he said that he had received more e-mails about the Blood Rodeo than any other build. I'm not. Bikers are Toughness 5 all of the time. They can get 5+ Feel No Pain on just about everything. If they get into hand-to-hand and can't hurt the enemy, they can disengage.
If you will ally them with the boys in blue, you can make them scoring. Kirby goes into all of the details right down to weapon upgrades.