Installed new rollers and lost top speed
 

Installed new stock rollers from the dealership on my Zuma 50f yesterday and lost 3-4 mph off the top speed.

Anyone have an idea of what's going on here?

Thanks

the only thing that makes sence is someone put in lighter than stock

i had 6g in my zuma, the bike is limited to 42 mph anyway, depending on your weight go for 6g, if over 220lbs go to 5

This could also happen if the rollers are the wrong size or the belt was excessively worn. Take one of the rollers out and measure it to make sure it's the correct size. (Maybe they gave you rollers for the previous generation 2T Zuma?)

lost speed Zuma new weights.
 

I'm new to the forum and scooters in general but I've spent the last 3 months of quarantine arguing with my wife and swapping weights in my scooters and my bro's scooter. 2016 Zuma 3rd gen 50f, 2006 Vespa lx50 and Roughhouse...who knows what year. I'll start with the advice then why. That way you can skip the reasons and solve the problem.

Buy Dr. Pulley Sliders. 4.5 to 7g. Stock weight is almost 7g.
7 Grams if you are happy with acceleration,
4.5 if you need more acceleration. The top speed will not be affected.
Purchase sliders, not rollers. Dr. Pulleys work. I don't know other brands but I do know I purchased some knock off (roller weights not sliders) and they were brittle and fell apart.

The weights only control at what RPM the variator spins. Your top end issues may be a result of an obstruction which prevents the pulleys from closing or opening all the way. The front pulleys (with washer removed) should pull together and push the belt to the utmost part of the wheel, bigger = faster, and the rear needs to spread apart to get that belt down to the smallest part of the plates. Think of a 10 speed bike with the big front chainring and wee little small cog.

The Dr. Pulleys are angled to allow the disks a bit more movement for slightly faster top end. I tested it with a sharpie marker with the old roller weights and the sliders **yes the speedo too. Dr. Pulley did not lie to me.. Bless his heart.

The Roughhouse, which is not mine, rips. I've been chasing my friend since installing the 4.5g sliders on it. *stock was around 8. That Chinese scooter cruises at 45, sometimes 47 with a tail wind.

The Vespa LX-50 has been taken as far as I can take that old girl. 4g sliders, down from stock 6.5, new main jet up to 86 from 72 or so. mesh air filter. It cruises at 42ish.

2016 Zuma 3rd gen- currently stock. I just bought it. It rides nice but needs some zip. I'm still waiting on my slider weights and just ordered a Dobeck Performance EJK to tune the fuel injection system. I'll update this thread with the slider swap, then the Dobeck tuner results (with sliders) fingers crossed.

The original rollers were worn down, allowing a slightly higher final drive ratio, sort of like having sliders installed.
- the newly installed stock rollers have a larger diameter than the worn ones, dropping the final drive ratio again.
-Just my 2 cents.