Dr. Pulley 15x12 Sliding Roller Weights 4.5 Gram

I'm going to start by saying that I know nothing about upgrading and increasing scooter performance. I read about these roller weights and decided to purchase them because they were priced right and accessible. It is unbelievable the difference that he made. These went on a bone stock 2007 Yamaha C3 that topped off at 36 mph with the wind on your back. After installing these and removing the small washer the limits the movement of the belt the scooter gained at least six to seven miles an hour we're in now goes past them 40 mile an hour gauge mark.

Put these in my 2008 Yamaha C3, and it was a very easy installation all things considered and it's a noticable improvement, nothing crazy of course but definitely improves acceleration and top seed

Work a lot better if you pay attention and put them in correctly the first time. They will go in a couple different ways. Helped my pickup off the line in Yamaha c3.

These are great. I gained 5 mph from these in my stock variator on my 2009 Honda metropolitan. Definitely worth it and easy to install of you got the right tools.

Stellar performance on my Yamaha C3! 10/10 would do again. The cheapo, no-name rollers were garbage in comparison. Don't waste your money.