Author Topic: Drive belt width  (Read 2933 times)

Peters

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Drive belt width
« on: February 16, 2012, 02:58:35 AM »
I ordered a new belt a couple of days ago and received it today. In my manual it says the standard drive belt width is 18 mm and the service limit is 17 mm. Simple enough right? So last time I had my CVT cover off I read 17 mm drive belt width with my $200 dial caliper. So I thought, okay I need a new belt. Well just out of curiosity I measured my new one. 17 mm. What the F@@@. The new belt is a Gates Kevlar and even says on it 748x18x28. I even measured with a engineering scale and still only 17 mm. What am I missing? Why would I put in a new belt that's already at the service limit?
*2010 People 50 2t with 70cc kit and more
*2001 ZX-50 beater

Calothrix

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Re: Drive belt width
« Reply #1 on: February 16, 2012, 04:21:24 AM »
Return it!  Seems like there is not much margin for error with only a 1 mm difference between a new belt and one that needs to be replaced.

zombie

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Re: Drive belt width
« Reply #2 on: February 16, 2012, 04:23:14 AM »
I was on the phone when I got home about the very same thing w/ SPI  (Scooter parts International).  EVERY Manuf. has a different Spec for your scoot somehow. Perhaps you have a mis marked belt but I have found the same thing. Some are longer/shorter/wider/Diff. angle. So far the belt that fits MY scoot best is the Malossi 738x18.5x28. Other makers in the same labeled size are all different. The reason for all this as I am told is each Manuf. makes the BEST compromise in size (they feel) to gain the MOST Perf. out of that size. So it really comes down to which one suits your needs. I have spent a couple hundred on belts to find mine. So I'm saying try it, and see what you think. If not order another, and you have a pretty new spare. Tunning Bro!
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

zombie

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Re: Drive belt width
« Reply #3 on: February 16, 2012, 04:25:05 AM »
YO! Calothrix! What up my Ni?....  ce friend
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

Peters

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Re: Drive belt width
« Reply #4 on: February 16, 2012, 04:36:27 AM »
That's kinda what I was thinking. I mean the part # is printed on the belt. It's definitely the right one.

To be honest I like the way the belt in there performs at 17 mm. Probably because I run pretty heavy rollers. 9g or 8.5 I can't remember.

I'll try the new one(at some point). Thanks zombie
*2010 People 50 2t with 70cc kit and more
*2001 ZX-50 beater

wordslinger

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Re: Drive belt width
« Reply #5 on: February 16, 2012, 09:09:48 PM »
...i'm running 743-20-28 on my s9....
..every mod (action) necessitates a (reaction) mod..

zombie

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Re: Drive belt width
« Reply #6 on: February 16, 2012, 09:21:25 PM »
...i'm running 743-20-28 on my s9....
What Manuf.? And what size is the Fact. belt?
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

wordslinger

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Re: Drive belt width
« Reply #7 on: February 16, 2012, 09:26:15 PM »
..itsa gates premium...

..my s9 had the same oem belt as both my a50s and all 3 of my ppls....

..roughly a 729...
..every mod (action) necessitates a (reaction) mod..

zombie

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Re: Drive belt width
« Reply #8 on: February 16, 2012, 09:38:05 PM »
That's my point A 14mm longer belt can NOT work at all if the stated #'s were actual. It's just trial, and error till you find the best one for your needs.
My OEM belt reads 732. Tha Malossi reads 738. The Gates reads 738, and is shorter than the OEM 732. I installed a Ruckus Var on the zx (over range) and am now using a 749 (forgot the brand Scooter west sells them) but the Malossi 749 is way too big. I can almost install it w/ out taking off the Var.
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

streido

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Re: Drive belt width
« Reply #9 on: February 18, 2012, 09:43:49 PM »
I ordered a Gates belt last year when i needed a new one,that was the same,the size written on the belt didnt match the actual size both in width and length,it was a good cm+ shorter.
I ended up buying a Malossi one and that measured out fine.
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zombie

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Re: Drive belt width
« Reply #10 on: February 18, 2012, 10:13:00 PM »
It would be too easy to give consumers the REAL numbers.
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

wordslinger

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Re: Drive belt width
« Reply #11 on: February 19, 2012, 04:37:55 AM »
...i gots some crazy harmonics goin on thru my mid-range now...

..i think it's due to  my belt...cheap 729 chinese....
..every mod (action) necessitates a (reaction) mod..

blue

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Re: Drive belt width
« Reply #12 on: February 20, 2012, 10:39:39 PM »
...i'm running 743-20-28 on my s9....
wow wonder how that size would work on my agilty. I beleave the one I got now is 18 ---20 sounds better.

streido

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Re: Drive belt width
« Reply #13 on: February 20, 2012, 11:08:00 PM »
wow wonder how that size would work on my agilty. I beleave the one I got now is 18 ---20 sounds better.

Better use a gauge and measure the space at the bottom of the rear pulley blue, if its too wide it'll either shred to bits or all your gearing may go to pot, or both. Im goin to strip mine down in spring and give it an overhaul, may even fit an open filter and mess around a bit with different belts, just for fun  :D
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blue

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Re: Drive belt width
« Reply #14 on: February 20, 2012, 11:11:20 PM »
It would be nice just to fine a few dif. sizes to fit. with no worrys.

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