Alvarez and Julio Cesar Chavez Jr. ready for tough fight

Canelo Alvarez, left, and Julio Cesar Chavez Jr. will square off on May 6 in Las Vegas

How much would Alvarez, who has been boxing at 154 and 155 pounds, be willing to go up in weight? And how much would Chavez, who has been fighting between 168 and 172 in recent years (and struggling badly to make it), be willing to come down?

They finally settled on a catchweight of 164.5 pounds, with significant financial penalties if either misses weight, for their 12-round fight on May 6 (HBO PPV, 9 p.m. ET) -- Cinco de Mayo weekend -- at the T-Mobile Center in Las Vegas.

So on Monday, when the fighters and their teams kicked off a four-city, two-country media tour/fan fest to promote the bout, thousands of fans and hundreds of media showed up for the kickoff event in Mexico City. Naturally, the weight issue was a hot topic of discussion, as was the meaning of the fight to Mexican fans.

"It's a new weight, so I have started to spar with heavier partners, which everyone will notice come fight night," Alvarez told the crowd. "Fights between Mexicans are usually the biggest, and I want this fight to be a mark on the legacy that many fights like this have left behind in Mexico's fight history."

Alvarez (48-1-1, 34 KOs), the former middleweight world champion and a reigning junior middleweight titlist, will fight nearly 10 pounds heavier than usual, but putting the weight on won't be a problem. For former middleweight titleholder Chavez (50-2-1, 32 KOs), however, taking the weight off is always an issue, but he said he is working hard.

"I've been making my way to this fight. My last fight was at 168 pounds," Chavez said of his 10-round decision win against Dominik Britsch on Dec. 10. "This fight isn't going to be any different from any other fight that I have had in the past."

Chavez Jr. had the support of his legendary father, Julio Cesar Chavez Sr., at Monday's event.

"I foresee a real tough fight. We have seen the best of Canelo, but we have not seen the best of my son," Chavez Sr. said. "I firmly believe that with a disciplined training camp, Junior is able to knock out not just Canelo but anyone in his way."

The tour, which is free to fans, continued Tuesday at the Hard Rock Cafe in New York and will be followed by a stop Thursday at 1 p.m. CT at Minute Maid Park in Houston, where Alvarez scored the 2015 Knockout of the Year when he erased James Kirkland with one shot in the third round. The tour concludes Friday at 2 p.m. PT at Plaza Mexico in Lynwood, California, just outside Los Angeles.

Jose "Chepo" Reynoso, manager and co-trainer of Alvarez, gave credit to both fighters for finding a way to bridge the weight gap.

"We have to recognize the sacrifices that both fighters have made to make this fight possible for all the fans who have been asking for it. Julio will have to drop to a weight and Saul will have to go up to a weight he hasn't fought at," Reynoso said. "What will happen on May 6 is an arena filled with thousands of Mexicans who will come together to sing the Mexican national anthem together, and show the U.S. that we are more unified than ever before."

Golden Boy Promotions CEO Oscar De La Hoya said the driving force behind making the match was Alvarez, who wanted the fight that fans have talked about for years. It appeared it might not happen because of the increasing weight discrepancy between the fighters. But when Alvarez went to De La Hoya and told him and Golden Boy president Eric Gomez to find a way to make it happen, they were able to work it out.

"Saul was the one who wanted this fight, and my duty as a promoter is to put together the best fights," De La Hoya said. "Mexican boxing is the best, and when you have these two hot boxers who want to give the best to the fans, we couldn't pass it up."