2012-01-28

WARNING! bad Piaggio rollers

lower quality brings early failure

2012-01-28 why the new rollers fail
2012-01-26 another set of early failing Piaggio rollers
2011-09-22 initial post early failing Piaggio rollers

2011-09-22 early failing Piaggio rollers

My first original factory installed rollers lasted 37000 km and looked better than this original Piaggio rollers batch no: 102829 after the 120000 km they should last without defect . (For more info on the old rollers see: inside cvt belt and rollers)



As you know I use only 4 of the 8 rollers in my Colt Conversion and that worked very well with the factory installed set. I switch the used set after around 10000 km and alternate the compartments they run in in the driving pulley. I also check for wear or problems in between.
When 3 month ago I did the test without the 2mm washer and some of the thread of the driving pulley rod got stripped (see: Malaguti Spidermax - I am so screwed) I installed the unused 4 rollers and noticed a more than usual wear with the new ones. One had a crack halfway through the plastic already (see above).

The new rollers were less than 4000 km in action and after a very pleasant beginning (171 km/h V-max) and a very good response and acceleration I noticed after a long 8 hour ride that my V-max had dropped to 140 km/h when the rpm limiter kicked in.
Now this is a warn signal that something is wrong with the transmission but my Spidermax had developed a slow dripping water leak during the same tour and my mind was around a cracked engine block and if I would make it home with the leaking engine.

As it turned out my water pump seal is leaking and the dripping I noticed came through the weeping hole what has just this job to expel water in this case.

But back to the rollers. A few days ago during driving up a steep hill with 120km/h, the rpm limiter kicked in also and that was when a warning bell in my brain rang loud enough to get my attention.

At home I opened up the CVT and saw that one roller had lost the plastic sleeve and was grind to a triangle.
the surface of the defect roller compartment was slightly nicked but still in a very good shape,
nothing what a bit of fine sandpaper cannot fix.
.
destroyed roller side A

destroyed roller side B
The metal plate where the rollers push against did not even had a scratch on it. I put the 8000 km rollers back for now except the ones with the crack and have to order a new set.
The Spidermax runs again as noting has happened.


2012-01-26 another set of early failing Piaggio rollers

Half of the new original Piaggio roller batch did last only 5650 km before one roller started to disintegrate.
As you can see the quality is quite different between these rollers. One has no deformation, one has a tiny deformation and the the third one is a shows a beginning deformation. All three rollers have next to none visible flat spots or other wear pattern. The fourth roller plastic casing broke in two and the metal part shows aggressive abrasions. The interesting thing is that the driving pulley inside where the rollers are held shows no sign of damage ore wear since I caught the breakage  (suddenly higher rpm at high speed and RPM max at around 130-140 km/h) within 100 km distance.





2012-01-28 why the new rollers fail
I keep all the parts I change in case they are needed for further reference, so I got the original factory installed roller which lasted for 37000 km (19000 in the original 8 roller setup and 18000 km in the 4 roller Colt Conversion setup) and compared them to the newer version you get as replacements.

cracked in America in a MP3 - no info when purchased

from the 28/09/2011 batch

from the 25/11/2009 batch

One reason why the rollers fail is easy to spot. The plastic material splits apart as if there was a weak seam. I do not know if this is designed on purpose to fail early, or if there is an unnoticed defect in the machine what makes the plastic part, but failing all the same way in a batch from 2009 and 2011 also in different scooters in Europe and America looks like a more global problem to me.

both metal inserts are the same weight
It is easy to see that Piaggio changed the metal part of the roller. It is thicker now

Now you can easily argue that there is too much pressure on only 4 rollers since there are 8 where the pressure is normally distributed. But keep in mind that these rollers fail mostly even before half their factory service life, that the original factory installed rollers did last with much more abuse (see the other posts) over 3 times their changing interval and that there should be always a safety margin be build in.

3 comments:

  1. Hi, We are manufacturer of Face Moving Drive for Kinetic Engineering Ltd., India. They are doing assembly at there end. Same problem of roller wear is being highlighted by KEL from last couple of months. They are saying this is the only problem of Roller track poor finish. As this is the same problem you have faced, we just want to know whether this is problem of roller track finish or roller poor quality.
    Please suggest.!!!!!!!

    ReplyDelete
  2. Hi, We are manufacturer of Face Moving Drive for Kinetic Engineering Ltd., India. They are doing assembly at there end. Same problem of roller wear is being highlighted by KEL from last couple of months. They are saying this is the only problem of Roller track poor finish. As this is the same problem you have faced, we just want to know whether this is problem of roller track finish or roller poor quality.
    Please suggest.!!!!!!!

    ReplyDelete
  3. dharam, I wrote Piaggio to inform about the bad Roller quality but no response. Dr. Pulley has a much better quality in material right now. The old rollers from Piaggio -2007 were of much better quality and material.

    ReplyDelete

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