The lemon laws are from state to state, if you purchase out of state it gets real complex.
Normally you have the obligation to return the bike to the dealer for a warranty claim. That typically would be local.
So you have your state and your rights as a consumer in your state, but you bought it technically in another state. That other state has laws that regulate the sales of motor vehicles with it.
So you actually have the obligation to return the vehicle and under the laws of the state it was purchased if they have lemon laws they have to repair it, under its warranty.
Your warranty what does it state, does it state they will come pick up the vehicle? Does it state that?
You had to return it to them within 14 days?
“If you have the vehicle in your possession for more than 14 calendar days and it has been in use, you will not be eligible for return, refund or replacement. You can send the vehicle or parts to us at your own expense; we will repair it and send it back to you at our cost”.
http://www.superiorpowersports.com/articles.asp?id=133
Also any legal action would require a California Attorney and be claimed in Los Angles County court.
Your correspondence should have been a request for an RMA, that the vehicle has a bad frame weld and sent images of that. All or any other request would be unnecessary then, why list parts if the frame is bad the whole vehicle needed to be returned.
If they did not offer an RMA then you would need to return it at your cost and ask for either it be repaired or replaced.
The only damages you would have had would be the cost to return it, which you could regain in court but you would need to file that claim in California.