Author Topic: OK--- What if............  (Read 3308 times)

blue

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OK--- What if............
« on: June 20, 2012, 07:59:13 PM »
OK back to the drive belt. What if I put a drive belt the same size and as the stock belt.But not a scooter belt I found some belts at a hardware store that sales good strong belts but they dont have the v cut outs its a drive belt from a lawnmower or something .would it work on a kymco. call me crazy if you like.

whiteknight

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Re: OK--- What if............
« Reply #1 on: June 20, 2012, 08:24:20 PM »
dont know to be honest. do you mean the vee bits as in the little bumps that run all around the bottom of the belt because apparently thats what gives the belt the grip... but i guess if you wanted to have a go at trying that type of belt then be my guest and let us know how you get on with it and if the transmission and bike survive the test.  another thing....wont there be alot of slippage from where the belt gets hot??

i guess you will  get alot of "dont do it blue" and "your gonna break it" so im going the opposite way and saying give it a try.
Courage is measured in how much tyre you use.

2010 Kymco Agility 72..Naraku 72cc race cylinder...Naraku 50cc race head
Naraku Race CDi...Polini free flow filter...Motoforce Racing Carb
NGK Irirdium plug...Naraku Race Variator...Malossi fly clutch
Stage 6 cnc clutch bell...1500 Rpm torque sprin

streido

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Re: OK--- What if............
« Reply #2 on: June 20, 2012, 08:36:31 PM »
OK back to the drive belt. What if I put a drive belt the same size and as the stock belt.But not a scooter belt I found some belts at a hardware store that sales good strong belts but they dont have the v cut outs its a drive belt from a lawnmower or something .would it work on a kymco. call me crazy if you like.

We have those type belts at work and i did think the same thing a while ago. Once i had a good look at them tho i figured they would just slip since like WK said they dont have the V's and were quite smooth on the sides.. Tjey dont flex as well either so would prob break something. Think theyre more meant for fixed drives like on a pedastal drill etc not to slide up and down like a scooter cvt belt does.

Chaos is my co-pilot.

whiteknight

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Re: OK--- What if............
« Reply #3 on: June 20, 2012, 08:38:50 PM »
hmmm true that to much stress and that would snap and chew everything up. be a right mess.
Courage is measured in how much tyre you use.

2010 Kymco Agility 72..Naraku 72cc race cylinder...Naraku 50cc race head
Naraku Race CDi...Polini free flow filter...Motoforce Racing Carb
NGK Irirdium plug...Naraku Race Variator...Malossi fly clutch
Stage 6 cnc clutch bell...1500 Rpm torque sprin


mono

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Re: OK--- What if............
« Reply #5 on: June 22, 2012, 08:27:16 PM »
I have owned a few vespa mopeds that had a smooth drive belt in stock setup, no variator or contra spring, just two fixed pulleys and a clutch.

I tried a belt with these V shaped incisions a few times, which was suggested as a performance mod by my local dealer.

The smooth belts had at least the same amount of grip as the ones with incisions (you could tell by the amount of tension you had to set them to before they would slip) - it's just like slick tyres on a dry road I guess.

The V shaped incisions on our belts are only supposed to make them more flexible for increased efficiency as far as I can tell...


whiteknight

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Re: OK--- What if............
« Reply #6 on: June 22, 2012, 10:45:59 PM »
yea but then this was on a vespa, for a CVT transmission you need play in the belt aswell as the flex so it can be used efficiantly in the pulleys. with a solid belt you dont have the flex and im guessing it would be a hell of alot more rigid and wouldnt allow for any variance....im guessing....please correct me if im wrong..im always willing to learn.
Courage is measured in how much tyre you use.

2010 Kymco Agility 72..Naraku 72cc race cylinder...Naraku 50cc race head
Naraku Race CDi...Polini free flow filter...Motoforce Racing Carb
NGK Irirdium plug...Naraku Race Variator...Malossi fly clutch
Stage 6 cnc clutch bell...1500 Rpm torque sprin

blue

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Re: OK--- What if............
« Reply #7 on: June 22, 2012, 11:02:11 PM »
we need wordslingers help on this.

mono

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Re: OK--- What if............
« Reply #8 on: June 22, 2012, 11:51:22 PM »
Quote
yea but then this was on a vespa, for a CVT transmission you need play in the belt aswell as the flex so it can be used efficiantly in the pulleys. with a solid belt you dont have the flex and im guessing it would be a hell of alot more rigid and wouldnt allow for any variance....im guessing....please correct me if im wrong..im always willing to learn.

I don't think flexibility of the belt has much to do with the ability of the variator to change it's width and therefore the diameter at which the belt will travel.

Looking at the way a belt travels along rotating pulleys it seems obvious to me that flexibility only matters beyond the point of first contact - the belt touches the "pulling pulley" in a straight line at a certain location - and that point defines the diameter - the belt only gets bent where the pulley rotates further...

Strictly speaking, the straightening of the belt at the "exit" side of the pulley will even compensate for the resistance against bending at the "entrance" side since rubber is mostly elastic. The only loss will be from its non-elastic behaviour, caused by the fact that rubber is not an ideal spring and wil always convert a bit of the change in shape into heat instead of storing the energy like a spring does...

physics boring yeah  ;D

streido

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Re: OK--- What if............
« Reply #9 on: June 23, 2012, 01:00:22 AM »
Unless theyre like 50 cents each i would stick to a proper belt, why take the risk?  :o
Chaos is my co-pilot.

blue

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Re: OK--- What if............
« Reply #10 on: June 23, 2012, 02:37:37 AM »
there only 10.00 but the way it sounds I well be waiting for the stock belt.

zombie

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Re: OK--- What if............
« Reply #11 on: June 23, 2012, 03:24:03 AM »
I don't think flexibility of the belt has much to do with the ability of the variator to change it's width and therefore the diameter at which the belt will travel.

Looking at the way a belt travels along rotating pulleys it seems obvious to me that flexibility only matters beyond the point of first contact - the belt touches the "pulling pulley" in a straight line at a certain location - and that point defines the diameter - the belt only gets bent where the pulley rotates further...

Strictly speaking, the straightening of the belt at the "exit" side of the pulley will even compensate for the resistance against bending at the "entrance" side since rubber is mostly elastic. The only loss will be from its non-elastic behaviour, caused by the fact that rubber is not an ideal spring and wil always convert a bit of the change in shape into heat instead of storing the energy like a spring does...

physics boring yeah  ;D


All of that is the reason for the bumps on the inside of the belt. I forget the term but its a relief for when the belt is at it's smallest on the drive boss.
"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: OK--- What if............
« Reply #12 on: June 25, 2012, 07:33:35 PM »
I forget the term but its a relief for when the belt is at it's smallest on the drive boss.

..dont do it blue!!...lol..

..zombie is right, if you run a "un-bumpy" belt, the heat and stress of trying to make that tight turn around the drive boss will cause he belt to crack around it's o.d.
..every mod (action) necessitates a (reaction) mod..

whiteknight

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Re: OK--- What if............
« Reply #13 on: June 25, 2012, 08:27:29 PM »
yea but then this was on a vespa, for a CVT transmission you need play in the belt aswell as the flex so it can be used efficiantly in the pulleys. with a solid belt you dont have the flex and im guessing it would be a hell of alot more rigid and wouldnt allow for any variance....im guessing....please correct me if im wrong..im always willing to learn.
I forget the term but its a relief for when the belt is at it's smallest on the drive boss.

..dont do it blue!!...lol..

..zombie is right, if you run a "un-bumpy" belt, the heat and stress of trying to make that tight turn around the drive boss will cause he belt to crack around it's o.d.

thats what i tried explaining in my post i've qouted within this one.
Courage is measured in how much tyre you use.

2010 Kymco Agility 72..Naraku 72cc race cylinder...Naraku 50cc race head
Naraku Race CDi...Polini free flow filter...Motoforce Racing Carb
NGK Irirdium plug...Naraku Race Variator...Malossi fly clutch
Stage 6 cnc clutch bell...1500 Rpm torque sprin

streido

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Re: OK--- What if............
« Reply #14 on: June 25, 2012, 08:42:34 PM »
I forget the term but its a relief for when the belt is at it's smallest on the drive boss.

..dont do it blue!!...lol..

..zombie is right, if you run a "un-bumpy" belt, the heat and stress of trying to make that tight turn around the drive boss will cause he belt to crack around it's o.d.

Where you been Pops? The kids have been running about the house wrecking everything the last few days  :o

They were fine 1st few days till all moms drink and drugs ran out but then they just tore the place up.

Where is mom anyway? Hope Z didnt get sooked up in that storm over Swampland  ???
Chaos is my co-pilot.

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