Scooter cvt, changing gearing

[SandraL]

Scooter cvt transmissions rely on weights in the variator, mounted on the crankshaft, moving outwards under centrifugal force to raise the gearing. ie make the crankshaft pulley larger.
The rear pulley is spring loaded. As the front pulley gets larger the rear gets smaller as the belt stays the same size.

If the variator weights were made lighter then the engine would need higher revs before the weights flew out, effectively keeping a lower gear for longer.
Would this be a good idea for a lightweight scooter with two adults?

Downside might be lower top speed as highest gearing might not be available with lighter weights.

If done how much lighter should weights be? 5%? 10%?

Current weights are 12grams each, qty 6 fitted.

Anyone been here already? Your thoughts please.

 

[David and Sally]

Wow! I have a cvt 300cc scooter and would not fiddle with it at all.

Whatever make I'm sure the makers have been through all that at design stage.

 

[SandraL]

Wow! I have a cvt 300cc scooter and would not fiddle with it at all.

Whatever make I'm sure the makers have been through all that at design stage.

Our scooter is only 110cc, if we had 300cc there would be plenty of power available even 2 up.
Sadly due to weight I need to stick with a lighter scooter, not willing to go trailor route.

 

[BouncyBoatFolk]

Hi, yes it's a do-able proposition, see video below. The no cost option of leaving out half the weights sounds like a good place to start.

Mike.

 

[SandraL]

Hi, yes it's a do-able proposition, see video below. The no cost option of leaving out half the weights sounds like a good place to start.

Mike.

Thanks , interesting video.
Have watched a few but a lot are talking about 50cc 2 stroke engines although principle is the same. Ours is 110cc 4stroke.
Suspect leaving half the rollers out will be a bit extreme hence the question of how much change is required, 5%? 10?%

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[BouncyBoatFolk]

There's probably a formula somewhere, if you can find it. It would save a lot of trial an error but I noted in the video the guy had a whole selection of weights at his disposal but didn't make reference to a fool proof calculation. So, getting a base figure with half the weights might be the best, but most tedious,and reliable way forward unless you're able to feed in all the variables for the calculation, weight of one rider, weight of two, goods carried, wet or dry road conditions, short distances, or longer haul,ect ect.
Mike.

 

[Richard n Ann]

Thanks , interesting video.
Have watched a few but a lot are talking about 50cc 2 stroke engines although principle is the same. Ours is 110cc 4stroke.
Suspect leaving half the rollers out will be a bit extreme hence the question of how much change is required, 5%? 10?%

Personally I'd leave it alone.
Remember the saying "Ain't no replacement for displacement"

 

[SandraL]

Remember the saying "Ain't no replacement for displacement"

How true!!!!!
But it comes with added kg

 

[David and Sally]

I suppose it’s the use you need from a 110cc. Two-up loaded with shopping up and down the Alps — obviously not. But a trip out to a local beauty spot or attraction?
If 50cc can happily get one person around then surely 110cc is good for two? I used to train learners on 125cc bikes and whilst they were not rockets they did get two people around.

Interesting topic though and will be interested in progress

 

[ivorantony]

When I brought a 50cc Honda vision it was adequate for single use, I put on a performance variator that
Did improve riding,
But two up it was a struggle on most hills so replaced her with the 110 vision, that works very well having been two up Porlock hill Devon with some shopping,
I may well fit another performance Variator for out planned trip to the pyrenees next year,
This is the company I used for the 50cc and the kit for the 110cc,

Variomatic Polini Maxi Hi-Speed Honda Vision 110 4T | Scooter Parts | Racing Planet UK |

Polini Sport variator: Optimized power transmission, durable due to reduced friction. Including variator weights 19x15.5 (8.1g).

www.racing-planet.co.uk

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[SandraL]

When I brought a 50cc Honda vision it was adequate for single use, I put on a performance variator that
Did improve riding,
But two up it was a struggle on most hills so replaced her with the 110 vision, that works very well having been two up Porlock hill Devon with some shopping,
I may well fit another performance Variator for out planned trip to the pyrenees next year,
This is the company I used for the 50cc and the kit for the 110cc,

Variomatic Polini Maxi Hi-Speed Honda Vision 110 4T | Scooter Parts | Racing Planet UK |

Polini Sport variator: Optimized power transmission, durable due to reduced friction. Including variator weights 19x15.5 (8.1g).

www.racing-planet.co.uk

Thanks, did you find hill starts easier 2 up with performance kit?
Was top speed affected?
Checked the website and they dont do our bike.
But the info for the honda 110 shows 8.1g weights.
So my weights need to be less than current 12g but maybe? no lower than 8g as a starting point??

 

[Richard n Ann]

The SH125 mode is only 13kg heavier and it has a third more power. They're noticeably faster off from the lights and out on the dual carriageway the locals zip past us when we're doing 50

 

[ivorantony]

It’s certainly made hill starts easier but that was on the 50cc, the few times I used her two up she still struggled on hills
After getting the 110 I haven’t had any problems two up, she was good for 50 mph which is plenty for us,
Next year we are planning a extended trip to Spain where the extra performance would come in handy so will more than likely uprate the Variator,
Correction I have just bit the bullet and ordered a kit, looks like a two week delivery so could probably update the effectiveness of the kit in three weeks time,

 

[SandraL]

Ok, thanks for the input.
At great expense, £4.99, I have ordered some 8.7g rollers.
This will give me 52 g with 6 of 8.7g rollers
or 62g with 3 of 8.7g and 3 of 12g rollers
or 72g original with 6 of 12g rollers
or 36g with 3 of 12g rollers.

Delivery will be a few days so be patient for an update.....

 

[jongood]

Ok, thanks for the input.
At great expense, £4.99, I have ordered some 8.7g rollers.
This will give me 52 g with 6 of 8.7g rollers
or 62g with 3 of 8.7g and 3 of 12g rollers
or 72g original with 6 of 12g rollers
or 36g with 3 of 12g rollers.

Delivery will be a few days so be patient for an update.....

Wouldnt up plating your motorhome and getting a better scooter be a more complete answer? going a bit bigger tends to bring bigger seats and better brakes and suspension etc.

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[SandraL]

Wouldnt up plating your motorhome and getting a better scooter be a more complete answer? going a bit bigger tends to bring bigger seats and better brakes and suspension etc.

Well its all compromise.
Already uplated from 4250 to 4750, dont think we can go more.
Back axle is at 2700 plated, running at 2500, but traction on front wheels to be considered too.....
Its the other toys and "essential" bits we carry that keep us to a lighter scooter.
Funnily ride is better on this scooter than the previous 125, but not like my old Honda Pan1100 .

 

[BouncyBoatFolk]

Wouldnt up plating your motorhome and getting a better scooter be a more complete answer? going a bit bigger tends to bring bigger seats and better brakes and suspension etc.

Not for a fiver and if it works [ it should do] then money well spent.
Mike

 

[jongood]

Well its all compromise.
Already uplated from 4250 to 4750, dont think we can go more.
Back axle is at 2700 plated, running at 2500, but traction on front wheels to be considered too.....
Its the other toys and "essential" bits we carry that keep us to a lighter scooter.
Funnily ride is better on this scooter than the previous 125, but not like my old Honda Pan1100 .

What on earth have you got in there? We carried our 300cc Aprilia Sport City in our 4500kgs similarly chassied but bigger Arto 74 with no issues along with 2 x bikes bbq, chairs, tools etc etc.

 

[jongood]

Not for a fiver and if it works [ it should do] then money well spent.
Mike

I agree its a cheap and interesting way to make it peppier, but won't address the other issues.

 

[SandraL]

We are happy with a light scooter and the compromises that entails.
Also like playing, eg changing rollers, to see what benefits it might bring.
If it doesnt work out still have the 125 scooter we have used since 2012.

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[SandraL]

8.7g rollers arrived today. 15min job to change out the 12g rollers.
Quick ride solo it seems more responsive up to 30mph, maybe due to effectively lower gearing.
Still gets to 50 mph ok solo.
Its wet and windy here and my pillion wont come out to play!
Am going to leave them in and see how it goes but first impressions favourable

 

[BouncyBoatFolk]

Excellent, thanks for updating the thread. Are you going to experiment with leaving out three of the original weights alone ?
Mike

 

[SandraL]

Not sure,
Moving from qty 6 at 12g to 8.7g has in total moved from 72g to 52g which seems a big move.

Intend to live with it for a while, other things in play are how worn is the belt and does the clutch slip.

Unlike a standard gearbox when it is easy to see revs rise as clutch slips the cvt makes that less noticable. Occasionaly we smell eau d'clutch. The clutch bell has some blueing.
Only a couple of times, bike is new to us, but usually climbing a rise when travelling 40 mph plus.

 

[Richard n Ann]

How long does the belt last?

 

[SandraL]

How long does the belt last?

I've no idea. Our 125 has 15k km and running fine.
This ,new to us, has 4800 miles. There was a fair bit of belt dust when I took casing off but dont know what is normal for these belts.

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[ivorantony]

Just an update, I fitted the new Variator https://www.racing-planet.co.uk/var...da-vision-nsc110-p-178708-1.html#.YVMGPcp4WhA
Including a new drive belt, and it goes like the clappers Very pleased with the enhanced performance,
The rev are definitely higher with a lot more torque lower down so should make the hills two up less of a struggle on the steep bits,

 

[Richard n Ann]

Just an update, I fitted the new Variator https://www.racing-planet.co.uk/var...da-vision-nsc110-p-178708-1.html#.YVMGPcp4WhA
Including a new drive belt, and it goes like the clappers Very pleased with the enhanced performance,
The rev are definitely higher with a lot more torque lower down so should make the hills two up less of a struggle on the steep bits,

Result I notice the SH125s seem to rev up more

 

[maison]

Having carried out the alteration what has happened to your insurance premium? Or have you not notified them?

 

[Richard n Ann]

The rev are definitely higher with a lot more torque lower down

The Honda Vision is air cooled so I hope it doesn't run hot

 

[ivorantony]

I don’t think that will be a problem, it’s moved the gearing down to maximise Torque at the lower speeds With slightly Higher revs,
An engine struggling to maintain revs under load will generate more heat than one higher up the Torque band,
I also gave it a service with new oil( full synthetic) air filter and plug and adjusted the tappets that where slightly loose, very pleased with the results so far,
We both used this scooter to ride up Porlock hill ( 1 in 4) in Devon a few years back ( in standard trim) reasonable successfully albeit slowly, I’m totally confident it would have no problem now,

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