"The stock variator is good. I would suggest ... Dr. Pulley Sliders - 28 Gram weight ...
If you REALLY want to change the variator, go with the Italian made Malossi - Multivar MHR"
I second the recommendation of 28-gram sliders from Dr. Pulley. I installed them on a 2013 BMW C 650 GT and they delivered a noticeable improvement in takeoff and mid-range power. No clue how top speed is affected because I never ride more than 80 mph. I'm at 13,800 miles on my 2019 GT and have a new Mitsuboshi belt, 38-gram sliders and insert pieces on the shelf ready to install at 15k miles (note: last few model years of the GT changed to 43-gram rollers, up from 33, that's why I have 38-gram. Anyone should verify the weight of their OEM rollers before installing new ones).
This week, on bike #2, a well-kept, 2004 Honda Silver Wing 600, I installed a Malossi Multivar variator AND Malossi Maxi Fly Clutch (the Silver Wing has the same basic set up as the BMW so I "practice" advanced work on the Honda). While I was in there I installed a new Honda CVT belt and Malossi 24-gram rollers (Silver Wing stock is 28-gram). The bike already had a Malossi Wild Lion exhaust that delivers an amazing growl from key-on to key-off.
The result? The 50-horsepower Honda sounds and accelerates like the 60 hp BMW. It might even be faster. It's a totally different bike. I found myself checking the dash a couple times on my first ride after the install to verify I was riding a Silver Wing. The Malossi additions changed it into a little rocket, pure fun, which is perfect for an old second bike I can rack up the miles on without fretting about it.
This was all the result of a little luck and leg work. While shopping for bike #2, I saw this old silver Silver Wing on Facebook Marketplace. It had a low price, $1,800, looked good in two basic photos, but the ad only had two words: "Clean title." I almost passed it by but figured it might be worth a look. You never know. I've had five Silver Wings so I like the bike. It's super-reliable.
Turns out the ad only had two words because the seller only knew a few words of English. He was a Brazilian mechanical engineer who had to leave the U.S. in one week to move back to his country -- he was desperate to sell the bike. As a bonus, he handed me $1,850 in Malossi and Honda parts he was planning to install. He gave me more in parts than I paid for the bike! Possibly the best deal of my 18 motorcycles, and I've had some great deals.
I thought about selling the parts but decided to install them. Very glad I did. Still not sure I'd spend all that money out-of-pocket on Malossi parts, but I'd consider it now. The performance boost on every ride is exhilarating. It also makes me appreciate the GT more. Rides on that are now a real treat, a luxury outing on the big boy, the best touring scooter in the world.