Keeping himself in trim has paid off for Beau Mertens who lines up for his first Melbourne Cup ride on Cismontane.

The Gai Waterhouse and Adrian Bott-trained stayer won his way into Tuesday's Cup when he led throughout in the Lexus Stakes at Flemington on Saturday.

Cismontane was ridden by Stephen Baster, but the gelding's 50kg in the Cup is below Baster's minimum weight.

With the hope of gaining a light Cup ride the apprentice has ridden through the spring at 52kg.

"I've kept my weight in order because you never know what can pop up," Mertens said.

"My weight's good and I'm feeling well too.

"He's not the easiest ride so I need to be strong as I've got six other rides on the day as well.

"I've got to be there feeling well and at the moment I'm feeling well and feeling pretty excited."

Mertens, who rides work for Waterhouse and Bott a couple of times a week at Flemington, says he will pick Baster's brain on Cismontane's quirks before Tuesday's race.

But he got a little heads-up on Monday morning when he rode the gelding in light work at Flemington.

He will also give his father, former jockey Peter, a call to get his thoughts on what the day could bring.

It will be the apprentice's first Cup day experience after spending last year at the Wangaratta meeting.

To try to help settle his nerves his master Mick Kent has given the 20 year-old the morning off with Mertens saying he'll go for a walk and jog to prepare for the day ahead.

Mertens is aiming to join Kerrin McEvoy who rode his first of two Cup winners as a 20-year-old.

McEvoy won on Brew in 2000 and again last year on Almandin.

"It would be unreal if Cismontane got up," Mertens said.

"Kerrin's a top jockey and if I can do half of what he's done I'll be happy with my career."