Variator drive face upgrade 139QMB?

[katt]

My drive face is worn, i can get regular replacement one for $14 shipped, there's only one other option for 139QMB - Naraku that cost $40 shipped, does it offer any advantage over stock drive face?

I can tell one difference this one has smooth polished surface and groves, dunno if this is better?

Stock has not very smooth surface more rough, does it provide better grip on the belt?

[GrumpyUnk]

Naraku makes nice looking stuff. Will it work better than stock? Dunno.

I got confused about belt grip when I was replacing the belts on my lawn mower. Factory belt was wrapped in fabric. I figured that would slip on the pulley surfaces, so opted for a 'bare' belt, with exposed 'rubber' sidewalls. It did not like my machine, and failed rather quickly. I went with a 'wrapped' belt, touting 'kevlar' components, and have been happy with it working.
If you think your belt is slipping, then it is due to one of several causes: glazed belt surfaces, loose belt, stretched belt, damaged pulley surfaces, glazed(polished) pulley surfaces, or lack of tension. May be you can think of more.
Do I think this expensive part will 'grab' better than factory? Not enough to justify its purchase price. Nothing against the firm, but suspect they are shopping nice looking parts to those who want to spend money on nice looking parts(of high quality). Will it work better or last longer? Maybe. Is it worth it? That's up to you.
I would suggest two brands of belts: Gates and Bando. Others will work, but those two brands seem to be a bit better than the rest. Their premium price is worth it when you figure they are less likely to leave you sitting by the side of the road with a shredded belt hanging inside your CVT case. Some belts give no signal that they are tired and thinking of committing shredoku, and just cut them self to pieces with no warning. I think the Gates and Bando will give signals that they want to quit.
tom

[katt]

I used

Gates PL20507 (POWERLINK STANDARD BELT) $14 on RockAuto, made of CR (Neoprene)

they also make

Gates PL30507 (POWERLINK PREMIUM BELT) $21 on RockAuto, made of EPDM (Ethylene-propylene-diene)

Here's difference, basically they claim 40-50k miles for CR and 80-100k miles on EPDM pretty sure it can shrink or shredd from mechanical wear way before that so i bought a cheaper one and rather replace it more often.

Gates make other variable speed belts, but dunno if they good for scooters.

[GrumpyUnk]

katt... the thought comes to mind that a belt can get damaged in so many ways that a difficulty with the variator or clutch can eat a belt way before it wears out, and that is not predictable. If the system were perfect, it could make sense to go for the higher cost, but my predictor predicts 'something' will not let the belt ever get close to the theoretical lifetime proposed by the manufacturer. Sooo, along that line of thought, I won't purchase $2 belts, but won't purchase $30 belts either. FWIW.
tom

[PirateLabs]

I agree with Grumpy here. You can buy a brand new Chinese stock variator that will come with that drive face, a slide bushing, fan, and variator for not much more than you said you would pay for a stock one alone. I got my new set for about $15 and free shipping last year and, I run a KOSO variator but I did use the slide bushing and the new drive face and fan and all is well.

Bill