After such a big battle, you'd think the show would be done. But it's back, in this season premiere of Senior vs. Junior. Senior is well-rooted for battle, but Junior plans on destroying his dad's business regardless; by building a rival shop just around the corner. Of course Mikey will be there along with an old friend Vinnie.

Paul Jr and team are hard at work trying to get the new shop in order. Senior is in total disbelief that Junior will be able to compete with OCC. Also Senior get's angry when Junior starts going after OCC's vendors.

Sr. and Jr. find themselves in front of a judge because Sr. is suing Jr. for his 20% ownership of OCC. Meanwhile, the team at OCC is hard at work on a chopper for ESAB, one of the oldest welding equipment companies in the country.

The guys at OCC are tapped to build the ultimate vehicle for the Science Channel's Meteorite Men. A tragic accident at Paul Jr. Designs prompts Senior to put his differences with his sons aside and he reaches out to Junior and Mikey.

OCC builds a ramp to launch a dummy dressed as Junior over a creek. Meanwhile, Junior and his team begin fabricating their very first chopper. Junior realizes that he needs help in the paint department so he recruits his old friend Nubs to the team.

Senior and the team at OCC are tapped to build a bike for the FBI and the local Newburgh Police Department. Meanwhile the guys at PJD are furiously attempting to fabricate both the Geico bike and the Anti-Venom bike in time for the bike rally in Sturgis, SD.

The pressure is on at OCC and Paul Jr. Designs as both shops race to complete their bike builds in time for the famous Sturgis bike rally.

OCC and PJD arrive at Sturgis to face off for the first time to see who will have the better bike. Junior wonders whether Senior will show his support by attending one of his reveals, but Senior has no interest in seeing either of his son's first bikes.

It's wedding bell bliss as Paul Jr. prepares to head down the aisle while PJD becomes swamped with e-mails from people interested in his bikes. But will Junior regret inviting his dad to the festivities?

OCC gets a bike build for the Chicago Blackhawks to celebrate wining the Stanley Cup. However, a miscommunication leads to the crew scrapping the build and starting over from scratch. Meanwhile, Senior rushes his dog to the emergency room.

The OCC crew continues building the Blackhawks bike while Junior meets with representatives from Carolina Carports who want PJD to build a bike for their company. Later, Senior makes an important decision agreeing to meet with a therapist for Mikey.

Senior sees a therapist, but his sons don't think he's making enough of an effort. Meanwhile, work continues on the Carolina Carports build at PJD; and Junior unveils his bike in North Carolina to a crowd of 400,000 people.

Senior and Junior are both invited to Jason's wedding. Junior gets a build from a longtime OCC client, frustrating Senior. OCC unveils the Hair Club bike in front of a roaring crowd in Washington.

Lee resurfaces, and talks to Senior about his relationships with his sons; Senior files a second lawsuit against PJD; OCC unveils a bike in New York City while PJD unleashes a top-secret bike in Florida.

A bike for St. Jude Hospital is unveiled; foreclosure rumors about OCC spread; an employee may lose his job at PJD.