The Honda PCX / Forza / ADV150 / SH Forums

I have a 2011 PCX125 with 5000 miles on her. Love the scooter. I run her hard, meaning, I usually run about 45-55mph constantly, mine tops out at 58mph by the speedometer. I average 85mpg. My question, how do I know when it is time to change the belt? I have noticed that I get a sort of rattling noise in the trans running at a constant 10mph. does not do it at any other speed. Thanks, Wallacem in Ga.

I think the only way to know for sure is to open the transmission cover and measure the width of the belt. The belt's dimensions for our scooters are (L) 816mm x (H) 10mm x (W) 22mm.

While the cover is open you may want to check the rollers, too, if you have not done so before. The instructions how to do this and the necessary tools can be found from this site.

I was going to say you know you need a new belt when your trousers keep falling down....
It's hard to tell without looking at the belt itself. but i would expect the bike to have a higher top end so may be worth looking at.

You know its time to change the belt by looking in the service schedule.
As far as I can recall its 12,500 miles.

Wallacem, I had the same with the stock variator. Adding sliders or an aftermarket variator allowed a higher top speed.

With the rattling at 10mph, it's possible the variator needs tightened too. Some judder during acceleration is normal, but juddering if you travel at a given speed is abnormal and should be looked at.

I don't know where in Georgia you live but there are at least 3 other members here that live in Georgia too, just FYI.
When the bike can't reach the top end it use to reach, it means that the belt is worn. Also, if it takes longer to reach your normal riding speed, it is time to change the belt. I would say to keep riding until it can't get to the speed you usually ride it at.

My bike has always ran up to 58mph and stop. It actually seems to have more power now that it is broken in, and has not lost anything. GPS says I am doing 55mph when the speedo says 58. Anyone out there that has a PCX125 that runs faster that 58 in stock trim, have you put a GPS on it to check the speedometer for accuracy?

Hi Wallachem,

I have a 2013 UK spec 125 and my top speed averages 56mph on the level.

I think it's commonly perceived as a 60mph + bike as my speedo for example hits 62mph flat out, which is indeed a GPS verified 56mph.

My 2011 125 shows 68 on the speedo but suspect this is about 62 gps but I've not checked. I have 13g Dr pulley sliders fitted but apart from that it's standard.

Pants fall down?

Drive belts should be replaced right before they break.
Absent that clairvoyance; keep a spare at hand.

Honda's service intervals should be taken as suggestions, because some of them make no sense at all and it appears they had to fill in the blanks with something so they did. For example on the 2015 PCX150:
"Belt Width: STANDARD = 22.6mm / SERVICE LIMIT = 21.6
REPLACE @ 15K MILES"
Dear Honda, How did you come up with exactly 1mm as maximum wear, and 15k as maximum miles? And why no time limit - ten years out the belts still good?
15k and 1mm are going to be in conflict with each other at some point.
Even a brand new OEM belt isn't 22.6mm out of the box! Below is the OEM belt with about 1k miles and it is technically below the service limit.


The Honda Service Manual is filled with errors and inconsistencies.

You haven't read the manual where it describes how to measure the belt.
Two flat surfaces need to be placed on the angles of the belt and measure the width between the two flat surfaces level with the top edge of the belt.
When measured correctly the width is wider than the belt.

gn2 wrote:You haven't read the manual where it describes how to measure the belt.
Two flat surfaces need to be placed on the angles of the belt and measure the width between the two flat surfaces level with the top edge of the belt.
When measured correctly the width is wider than the belt.

I did not see that part - thanks!
Don't you get tired of being right all the time?
BTW, love that Pink Floyd Meddle!

fun2scoot wrote:

gn2 wrote:You haven't read the manual where it describes how to measure the belt.Two flat surfaces need to be placed on the angles of the belt and measure the width between the two flat surfaces level with the top edge of the belt.When measured correctly the width is wider than the belt.

I did not see that part - thanks!Don't you get tired of being right all the time?BTW, love that Pink Floyd Meddle!

Trying to get my head around this - so, the edges of the belt are angled with wear from the variator, but should not the width of the belt at the top edge (which is where the measuring device would read) be the same as between two flat surfaces where they meet the top edge?

fun2scoot wrote:Don't you get tired of being right all the time?
BTW, love that Pink Floyd Meddle!

Nope, I'm frequently wrong.
At least that's what the wife says.

And everything is green and submarine.......

For sure...
Eons ago I turned a, then acquaintance, now friend, onto a song that he denied could cover the entire side of an album.
Later on, I showed him a song that covered both sides from the genius of Ian Anderson.
...so you ride yourselves over the fields,
and your wise men don't know how it feels....

My 2011 manual says the belt wear limit is 21.0mm

Thanks for correcting my method of belt measurement gn2.
It is a misnomer for Honda to call it the belt "width" - it isn't. It is the measurement of two divergent oblique angles at the belt's circumference. But no one would call it that so it's "width".
I measured again according to the manual using two razor blades as planes. The new Gates belt is 23.05mm. The OEM Honda with 1k was 23.20

It is really hard to do!

Not only is it hard to do, it seems ridiculous! Why not modify the width measurements to give the actual width measured from edge to edge without all this nonsense. Using the 'approved' method also calls into play things such as depth of the rulers edge you use to measure the two surfaces pressed against the edge - it will change if your rulers edge is slightly thicker or thiner. Silly and completely unnecessary. If the measurement was width as measured directly across, that would be accurate every time no matter what you use.

I still fail to see how measuring directly across would be different to what you would read if you ruler was very thin at the measuring edge and you measured right at where the side bits joined the top surface of the belt. The only reason for difference is the thickness of the rulers edge adding 0.5-1mm or so - stupid method.

Lets be honest, for commuting where top speed is really hit and where people start to see a fall off over time, the belt will last for ages at more modest speeds.

All good points. Here is one more:
If the bike is mostly ridden at or near top speed, then the sides of the belt could become slightly concave (relative to the circumference edges) from running on the circumference of the variator, making any measurement unreliable as the belt would have more wear than indicated.