CVT drive-train Inspection

[de dee]

You've GOT IT! You have been recaptured! Why ride one mile when ten will do! Someone on here said that....

  you said that when you where young,    and the oil should be changed hot, the particuls do not have time to settle, and get flushed out,. 

[scooterfan]

  you said that when you where young,    and the oil should be changed hot, the particuls do not have time to settle, and get flushed out,.

True, but in cases like this where oil changes takes place quite often, I think the oil temperature should rather be "mild" than hot.  Hot oil obviously means the aluminium housings will be hot as well. Due to metal expansion I never like to remove  drain- or spark plugs when the aluminium housings are too hot.
I think chances are just better that the hole thread at the housings might wear out....therefore my intention is to drain the oils only at very "mild" temperature.

[JJJoseph]

My intention is to have a proper look at my scooter's belt as soon as possible, and I would appreciate if anyone can let me know about the correct width on a brand new belt.
I would also appreciate any related info.

Thanks !

The width is almost irrelevant since the various makes are not always exactly the same from one make to another.  Close is good enough, and you won't be able to tell the difference.  If you're really hammering it, the belt will eventually start to show some loose threads after maybe 20,000km.  I've never had one break, even the cheap ones.  They seem like they could last a lifetime.  It's possible an expensive Kevlar belt just might last forever. 

[scooterfan]

The width is almost irrelevant since the various makes are not always exactly the same from one make to another.  Close is good enough, and you won't be able to tell the difference.  If you're really hammering it, the belt will eventually start to show some loose threads after maybe 20,000km.  I've never had one break, even the cheap ones.  They seem like they could last a lifetime.  It's possible an expensive Kevlar belt just might last forever.

After inspecting the belt, I do agree with your comments  for several reasons:

1. The belt is an original Kymco belt, and the current width was taken with a digital vernier. After just more than 8400 km the width of the belt is 19.01mm.
2. The belt dust found inside the cover, as well as a slight ridge at the top of the sides of the belt is a clear indication that at least some wear already took place, but nothing to worry about.
3. The “shiny” part at the rear pully (where the belt gets in contact with the two sides of the pulley) still indicates that the belt still moves almost right to the top of the pulley in “top gear”, so the little wear (20mm less 19.01mm = 0.09mm) during about 8400 km really does’nt bother me.
4. The belt still looks almost brand new, and I think it should last 20k without reason for concern.

In short - I really like my Agility’s AVT setup. I just had to clean some belt dust which was trapped inside the cover. The variator has cooling fins, not like all other 125 variators I saw at youtube. I think the fins at the variator definitely helps with cooling, and will help to extend the lifespan of all components. Everything just looks solid and reliable.
I will probably just remove the CVT cover at 16 000km to get rid of belt dust, and inspection.

[scooterfan]

Well, since my previous post I was thinking about these CVT transmissions again, and I realized that I was cought with pants down by a few Youtube videos which indicated that “top gear” ratio will change if the belt gets thinner.
This is simply not true. All  “gear ratios” will ALLWAYS remain the same - even if he belt becomes a lot thinner.
The reasoning for my statement is very simple - If the belt gets worn (thinner) and start “sagging” down into the rear pulley it will also start “sagging” down into the front pulley. The distance it will sag down into both pulleys will be exactly the same - therefore “gear ratio” will ALWAYs remain the same.

It might sounds like a “no problem” situation, but I am convinced that if the belts start sagging down into the grooves, the belt length will not be correct any longer - even if the belt did’nt stretch. Simply because the belt will be sitting deeper into both pulleys.
This means the “slag side” of the belt will cause an uneven grip on both pulleys, which will cause more stress and heat on the belt, as well as both pulleys - because the work load will be spread over a smaller area on all components.

In short - I decided to change the belt at 12 000 km, even if it “looks good” to last 20 000 km. Right or wrong, I am quite convinced that should the belts be replaced more often, the lifespan the pulleys might be extended.