Scott Redding and the Aprilia RS-GP MotoGP machine will both be attempting some winter weight loss.

While the Englishman already looks like he doesn't have an ounce to spare, at 1m 85cm he will take over from Loris Baz as the tallest rider on the MotoGP grid next year.

And while new team-mate Aleix Espargaro is only 5cm shorter, Redding was 'shocked' to discover the Spaniard is now 13kg lighter.

Redding says Espargaro weighs 66kg, rather than the 71kg given on the official MotoGP website (where Redding is listed as 78kg, 1kg lower than his current weight).

That difference suggests Espargaro may have lost weight during the season, to try and improve straight-line performance.

At September's Aragon round, the most recent dry event with a long straight that Espargaro attended, he was 13km/h down on top speed in qualifying. Team-mate Sam Lowes was slowest of all through the speed trap.

Redding certainly feels weight could prove crucial and is determined to get within 10kg of Espargaro by the start of 2018 testing.

"My plan is to cut some weight from now until Christmas and then build on my stamina ready for the new season," he said.

"I feel like I have a good opportunity next year and I need to put all the small things together. So I need to give - as every year - as much as I can.

"There's a few things I can tweak, like my weight. I can be lighter.

"I've tried to be lighter [in the past] and struggled because I needed the power. Now I don't need so much power to ride this bike and I'm getting more mature, understanding how to save energy.

"So I can reduce a bit of weight. It's going to be hard, but I'm going to do it! I need to do it."

Told that he barely has any body fat, Redding replied:

"The thing is, Aleix is 66 kg and that really shocked me. But in the end it's helping him on the bike.

"If Aprilia can cut a few kilos from the bike and I can cut 4-5 kilos from my weight, then another kilo from somewhere else, we can come to a package that's 8-9 kilos lighter. For me that's just an advantage.

"As I say, it's not going to be easy. Especially as it's not fat that I need to lose, but muscle in certain areas that I don't really need anymore.

"I'm tall and I've seen other guys lose weight. I was 83kg after the flyaways and I'm already down to 79kg. So I'm working in the right direction, I just need to keep going.

"It's a bit shit sometimes, but I'll do it and then see where I am after Sepang; decide what needs tweaking and then control my weight from there."

Asked if he had any dieting tips, Redding laughed: "Don’t f**king eat and keep pedalling!"

Aprilia meanwhile will be using more advanced methods to trim weight from the RS-GP, which got heavier during the 2017 season.

"We had a lot of ideas for developing the bike and each idea represented a trade-off between an improvement in performance and, sometimes, increasing weight," explained Aprilia Racing boss Romano Albesiano.

"So, we are now with a faster bike than before, but it’s slightly over the [minimum weight] limit.

"So for next season the target is to keep the same contents of the bike, maybe adding something, but come back again under the minimum weight limit [157kg] and be able to put some ballast."

Watch the video below to see Scott Redding dragging his elbow into pit lane!

Scott Redding: Elbow down into pit lane!

Redding felt much happier after his second test on the RS-GP, at Jerez, than during his Valencia debut, when he had tried Espargaro's set-up.

However Espargaro skipped Jerez to give his hand injury further chance to heal, meaning it was harder for Redding to gauge lap-time progress.

"It would have been a better reference if Alex was here, to see if we can close the gap to him," Redding said. "At the moment my target is to close the gap to the front obviously but also to Aleix, while using my settings on the bike.

"At Valencia, my set-up was more or less the same as Aleix, but it just didn't suit me at all! I couldn’t feel at home on the bike there. Nowhere near.

"Whereas [at Jerez] I said, 'let's go a bit my way'. Then it started to work and get better. Now I've got a good base and can ride it how I want.

"Aleix's style is quite different to mine, so we need to find something that works for both of us.

"It's just climbing the ladder and finding our way.

"We went, not the wrong way, but at one stage we put on a new tyre and I almost had a really big highside at Turn 3 because I was expecting more linear grip and it wasn't there. But with a used tyre it was.

"So you also need to understand that this bike is really good with used tyres. The problem is when you put the new tyre, if it's better or not.

"But this test was not really about the lap time. It's a shakedown for me to give the team information, like trying to make the bike a bit bigger in general. That's one thing they want to do for both riders just to be a bit more comfortable in the straights, the aerodynamics.

"The bike is small and there is not a lot of space. It's not really about handling, just rider position and having more space to do a few things. Like for me we're on the limit with the handlebars, so moving the fairing forward a bit to suit me.

"It’s hard to say what's top of my list now because after the work we’ve done I've got a lot of the understanding that I needed.

"I would like a bit more grip, to use the drive. It just seems to me that the bike doesn’t have initial grip. And if you do get grip and it breaks away, it breaks away fast. So you need to find a balance between grip and spin.

"But each day it's getting better. It's just time and the way the team work is unreal for me. We decide what we're going to do and stick to the plan… It's wicked."

Redding's experience at Pramac Ducati has also taught him to focus on getting a base set-up that is tailored around his needs right from the start.

"When I went to Ducati they gave me a bike and it was an average of a good base [set-up]. The guys going on to the Ducati now - Tito, Jack - are bonding straight away, like I did. But the problems come later.

"For me I prefer to find the way, bring some new parts to help me, understand what the bike needs and get stronger throughout the year."

The Sepang test takes place from January 28-30.