CVT advice needed.

[kavandershadow]

Howdy everyone.

I’ve put almost 3000km on my 50mm BBK upgraded 2018 peace sports renegade in less than a year, and now I’m starting to feel a big difference in acceleration and top speed.

I have kept up on the maintenance, and she runs like a top. I ride to work almost every day on it and recently seen a 3-4mph difference in top speed and slug-like acceleration. No bogging.

If memory serves me right, the stock cvt has a set of soft 1000 rpm clutch springs/1000 rpm contra spring. Correct?

I generally fly around town at or near WOT most of the time, weigh 170lbs and carry a few things (32oz water bottle... Coffee!)

Personally I now feel uncomfortable with the sluggish acceleration and top speed that has crept up on me.

What would y’all recommend?

Any particular belt brand?
1500 contra with 1500 C/springs make a difference over stock?
Different rollers?
¯\_(ツ)_/¯
I need to be fairly quick off the line and be able to hold 45-50mph steady. When the BBK was first installed with new belt/springs it took off really well and stayed comfortable at 45.

Thanks in advance!

[repherence2]

for sure you should get a new belt, if you know it lost that much speed.
you might need new rollers, they could be flat spotted (worn).
you might need new ramp guides for the variator, they could be worn.
rollers and ramp guides will be based off of inspection of the existing rollers and guides.

if you want it to be the same as when "the BBK was first installed with new belt/springs" do not fiddle with 1500 contra or 1500 clutch springs for now.

however, if you are interested in "tuning" the CVT, then you can delve into 1500 contra/clutch springs. that CVT is a balancing act. if you keep the same rollers in there but change to a contra spring that is +500 of what is in there now, the shifting will be different, it will variate at a different rate, thus affecting your acceleration performance. might be nicer going up hills or accelerating out of turns with the 1500 contra, but you probably would have to fiddle with roller weights. if your intent is to tweak the CVT to your performance liking, you end up buying different weight sets (or buying a tuning weight set to help narrow down the gram weight performance that you like), and then testing over and over and over and over. change only 1 thing at a time. so, if you are going +500 on the contra, do some tests with some different roller weights to find the performance that you prefer to ride at. you change your clutch and contra to 1500 at the same time, you might end up with massive frustrations in regards to getting it tuned. you go +500 on the clutch, it ends up having to rev up a little higher before the clutch starts to engage, and it changes the performance.

it's really up to what you prefer in regards to going 1500 contra and clutch.

if you just want it to get back to the way it was, guarantee you want a new belt.

is it time for a valve adjustment too?

[kavandershadow]

Indeed, it is a little confusing for me with roller weights, Kevlar belts vs whatever...

I know I definitely need a new belt since it’s the original that came with the scoot. I got a valve adjustment, new battery and a new spark
About 300km or so ago.

[geoffh]

Some very good advice already from rep,my 2cents if you were happy with the set up just replace belt and rollers but measure the old belt and get the exact same length replacement,depends where you live but bando brand get goods marks in the tech section,only my opinion but kevlar,racing,sport are just sales words to grab your cash.

Geoff

[repherence2]

Jun 13, 2019 15:03:33 GMT -5 geoffh said:

Some very good advice already from rep,my 2cents if you were happy with the set up just replace belt and rollers but measure the old belt and get the exact same length replacement,depends where you live but bando brand get goods marks in the tech section,only my opinion but kevlar,racing,sport are just sales words to grab your cash.

Geoff

I agree.
I have read a lot about Kevlar belts snapping. I have never run a Kevlar belt myself. I just run Bando or Mitsuboshi. stay away from the super cheap belts. from my experience with cheap belts, although for example it was marked as a 788 the cheap belt was actually shorter than a brand new 788 Bando belt. (788 because I have a 2T minarelli). I also noticed that the cheap belt was pretty stiff and when I ran it, the reinforcing threads began to peel away from the sides of the belt so I got rid of that belt.

you can use this belt change as a learning opportunity. you can compare the width of the existing belt to the width of the new belt. 1mm in width can make a significant difference in speed. that would be a good time to weigh your existing roller weights so you know what is in there in case you need to replace rollers later, at least you know what gram weight you need.

make sure you read up on CVTs.

make sure you tool up properly before you attempt to do the work. you probably will need a locking device to lock the drive face so that you can untorque the nut that holds the variator to the crank. you can find the locking tool on the internet. for me, I just use a rubber strap wrench to hold back the drive face while untorquing (for minarelli). the 4 stroke drive face has gear teeth on it that engages with the electric starter bendix, hence the need for a locking device.

maybe later you, as you get more familiar, you change your variator out. where I live, most moped shops sell KELI high speed variators. the roller ramps curvature is different from stock. the roller ramps also extend a little further out than stock so you end up with a little more top speed.

[kavandershadow]

So I ended up ordering a gates powerlink 669/18.1/30 belt to replace the stock 669 belt, I also ordered MMG 1000 & 1500 clutch springs and 1000 / 1500 contra spring. I have 7g rollers in the variator, but decided to buy a new high speed vari with a higher curve surface and a box of rollers between 5-8g off Amazon. I cannot find a crank locking tool for a good price, but the scoot shop in boca raton said they would install everything for $85.

I want to do it myself, but now with 2 kids and pregnant wife... I think I’ll let the shop do it so I don’t have my CVT guts all over the living room tile floor we just installed! (It’s been raining for almost 2 weeks straight here) and I have no garage.

It just sucks the closest place that works on scoots is 20 miles away, I don’t have much confidence in the belt lasting that trip... hope my gremlin bell gives me luck this weekend!

[kavandershadow]

Decided to buy a locking tool- and do it myself. the scoot shop BS’d me over the phone- rode 20mi in full gear (45mins each way) in crotch rot 103F weather during rush hour traffic to find the price to change the belt was $89 labor+ tax + parts! That’s a whole bucket full of NOPE! 

To change the belt, weights, springs: $220 labor+Parts+tax. I asked what type of belt they would replace it with- response was “some Chinese manufacturer”. “Standard” (China) belt: 29.99 
if I wanted a “performance racing belt” (gates standard powerlink) it was $39.99! Wtf?!?!? 

Rode straight home (after consuming almost a 1/2gallon of water!) and decided just to wait for the weights, springs, locking tool, and a gates powerlink over-width (18.1mm over stock 18mm) belt. Saved myself over 300$! 

Heres a couple pics of my current stock belt with its slack. No feathering yet but it’s sitting at 16.9mm right now. Any thoughts?
Edit: I did buy a new CVT cover gasket as well.

 

[AtariGuy]

Brent (90GTVert) has done a few good writeups and a couple videos detailing good cvt tuning, his youtube channel (90gtvert) has that video. Also be sure to browse the tech library section on cvt/transmissions

[aeroxbud]

They were trying to rip you off. It's only a 15 minute job to change rollers, and a belt. Then replacing it with a no name brand
Normally 1mm is about the wear limit on the scooters I have had.
It's not that hard to do. Go for it.

[jloi]

I agree , you made the right choice . I'm not that experienced but I just put new sliders in my variator . What helped most is I have a 20 volt Dewalt impact that I originally bought for work. drywall, metal framing etc. I had no idea it would work for my variator, clutch and rear axle nut but it does. Pricey but I needed it for work . Good luck . . we're getting all that rain too here in Orlando.

[streetsweeper]

I run the Gates belt and didn't pay $39 for it. Check your local auto parts stores. Have no idea where you live but most like Auto Zone or Advanced Auto sell them for around $19.00...Another tip, I have a tension gauge in my roll around, from my fleet mechanic days. If you can find one, buy it and learn how to use it. Pretty easy to do. Takes the guess work out of tensioning.

[pinkscoot]

I have a Harbor freight plug in impact gun . I usually catch the sale or coupon and get it for $29.99. For as little as it gets used its well worth it. Best practice is to only use it to remove the nut and use a good torque wrench to tighten. By good I mean not Harbor Freight.

[kavandershadow]

One thing I cannot find is a solid number on the torque spec for the variator nut. I’ve read 30ftLbs, 65, etc. I have a peace sports renegade. I picked up a cordless impact gun from Wally world for 34.99 rated at 345ftLbs. I have 3 torque wrenches from harbor freight and they are quite well made, 2 are just as good a calibration as my snap-on, one 3/4 is actually better.

[aeroxbud]

All the two strokes I have owned have been between 22-25ft lb. So probably somewhere in that region I would of thought. Sixty would be way too much. Give 30 ft lbs a go.