"The weight scale couldn't suit him better," says Sharrock, who rates alongside Kevin Myers as New Zealand's most feared winter trainer.
"He was really good last start at Trentham when he ran the second fastest last 600m back in the inside but that was when he was giving away 7kg to most of his rivals whereas this week they all come up to meet him in the weights. That is a huge help and we know he will love the heavy track so he has a lot in his favour."
Justaskme has won four and placed in three of his 10 starts on heavy tracks and this is the race Sharrock has earmarked for him so while he opened as the second favourite it wouldn't surprise to see him start close to the top elect.
That early favouritism sat with Secret Armour, who proved herself with a third at weight-for-age mare's level last start in a Rotorua race but she doesn't have heavy track form.
To emphasise how the weight scale suits Justaskme, Secret Armour gets her 2kg mare's relief but gives away 12 rating points which should be good for another 6kg of weight relief she doesn't get.
Sharrock's team is set to start the winter nightmares for bookmakers as he is even more confident about Darci La Bella (R5, No2) in the open sprint and more quietly so about Sophmaze (R4, No5) in the Listed Castletown Stakes.
"Darci Le Bella is a good horse like her older half brother Tavi Mac," says Sharrock. "She is good on any ground and has real class. She had a jumpout last week and flew so she is ready."
She will need to be as the sprint is a little winter jewel, with Spring Tide a proven Group 1 galloper who loves the wet and Racing Evens another mudlark backed as soon as the market opened, while Ima Roca Bee raced well on heavy tracks this time last year but is poorly weight.
Sophmaze finds herself in a strongish version of the Castletown Stakes where any black type would provide enormous upside for the close relation of Levante.
She ploughed through the Trentham mud last start courtesy of a beautiful Lisa Allpress short cut ride and Sharrock the filly's wide barrier doesn't concern him.
"This filly has really come on since that last win and she might be the most improved horse in the stable, which can happen with nice two-year-olds when they hit their straps.
"It is a nice enough field but I am not scared of many."