What do the numbers on contra/torque springs mean?

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mwilliamshs
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What do the numbers on contra/torque springs mean?

Post by mwilliamshs »

I get that clutch springs saying 1k (1,000) mean they allow the clutch to engage at about 1,000 rpm above the stock level.

I don't get why a contra springs ("torque spring" at scrappy dog scooters) would be rated this way. They're labeled "1k", "1.5k" etc. Is that number related to rpm? spring rate (lbs/in, etc)? something else? Just trying to understand the terminology.

Also, I get that lighter weights in the variator typically need a different contra spring to allow roughly equal takeoff and hillclimbing abilities after modifications so I'll likely need to change contra springs someday but what's the stock spring's rating? 500, 750, 1k, etc
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Re: What do the numbers on contra/torque springs mean?

Post by deuce217 »

Typically anything with a numeric value on aftermarket parts indicates the total rpm difference between that item compared to the OEM item. I.e. 2k clutch springs have approximately 2,000 rpm delay prior to clutch engagement. The contra spring controls the rate at which your transmission will "down shift" once the accelerator has been re leaved or more load has been introduced to the scooter. IMHO

The variator/ roller weights are a touchy item. They make a large difference on the acceleration of your hog. This weight should be tuned to the specific exhaust you are currently running. A SA50 AF16/ dio engine with a PG long pipe will typically like a lighter set of weights to allow high revs through the shifting. A z8 style pipe that is not designed for high revs will naturally perform better with a slightly heavier weight load. I run about 36 grams total weight in my whip when using a V8 pipe with great success.
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Re: What do the numbers on contra/torque springs mean?

Post by Wheelman-111 »

Greetings:

Deuce is correct. Heavier springs will delay the belt "shift" and raise RPM, just as lighter roller weights will. The difference in behavior will occur Off-throttle, as the heavy spring will upshift the belt more quickly than a lighter spring. Aside from measuring the spring diameter, you can dynamically test the spring's tension and compare this way.
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Re: What do the numbers on contra/torque springs mean?

Post by mwilliamshs »

deuce217 wrote:Typically anything with a numeric value on aftermarket parts indicates the total rpm difference between that item compared to the OEM item. I.e. 2k clutch springs have approximately 2,000 rpm delay prior to clutch engagement.

^That^is exactly what I meant by \/this\/
mwilliamshs wrote:I get that clutch springs saying 1k (1,000) mean they allow the clutch to engage at about 1,000 rpm above the stock level.
deuce217 wrote:The contra spring controls the rate at which your transmission will "down shift" once the accelerator has been re leaved or more load has been introduced to the scooter. IMHO
And^that^is exactly what I meant by \/this\/
mwilliamshs wrote:...Also, I get that lighter weights in the variator typically need a different contra spring to allow roughly equal takeoff and hillclimbing abilities after modifications...
deuce217 wrote:...The variator/ roller weights are a touchy item. They make a large difference on the acceleration of your hog. This weight should be tuned to the specific exhaust you are currently running. A SA50 AF16/ dio engine with a PG long pipe will typically like a lighter set of weights to allow high revs through the shifting. A z8 style pipe that is not designed for high revs will naturally perform better with a slightly heavier weight load. I run about 36 grams total weight in my whip when using a V8 pipe with great success.
No idea where that came from. Totally irrelevant. Not trying to be a * but c'mon, that was outta nowhere.

ORIGINAL QUESTIONS:

1) what do the labels (#s) on aftermarket contra springs mean?

2) what is the stock spring's rating (its #)?
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Re: What do the numbers on contra/torque springs mean?

Post by 1man8scoots »

deuce217 wrote:...The variator/ roller weights are a touchy item. They make a large difference on the acceleration of your hog. This weight should be tuned to the specific exhaust you are currently running. A SA50 AF16/ dio engine with a PG long pipe will typically like a lighter set of weights to allow high revs through the shifting. A z8 style pipe that is not designed for high revs will naturally perform better with a slightly heavier weight load. I run about 36 grams total weight in my whip when using a V8 pipe with great success.
No idea where that came from. Totally irrelevant. Not trying to be a * but c'mon, that was outta nowhere.

ORIGINAL QUESTIONS:

1) what do the labels (#s) on aftermarket contra springs mean?

2) what is the stock spring's rating (its #)?[/quote]


C'mon, Use the search function instead of being a *. I know the answers but best of luck ever getting info from me.
Duce just assumes you know nothing and was trying to help. Yet you just need someone to agree with everything you say for some obnoxious and lazy self validation.
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Re: What do the numbers on contra/torque springs mean?

Post by 1man8scoots »

Fwiw it is the Internet and people have to take it as it's value. Free information and free speech.
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Re: What do the numbers on contra/torque springs mean?

Post by tuserv »

:b2t:

ORIGINAL QUESTIONS:

1) what do the labels (#s) on aftermarket contra springs mean?
answered

2) what is the stock spring's rating (its #)?
zero

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Re: What do the numbers on contra/torque springs mean?

Post by curtis966 »

It's as simple as putting a stock contra and stock clutch with stock springs in and looking at your tach as you twist the throttle. When the clutch engages that's your answer for clutch springs. And when you feel it "switch gears" as its called that's the ratting for the contra. Done
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Re: What do the numbers on contra/torque springs mean?

Post by Wheelman-111 »

Greetings:

1. +1000, +2000 refers to the delay in shifting behavior compared to stock RPM.

2. No one knows. Measure according to my post with a bathrrom scale to obtain a spring rate in Kg./cm. or lbs./inch. The measurement that matters is within the length range of the spring mounted in the pulleys.
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Re: What do the numbers on contra/torque springs mean?

Post by patthesoundguy »

I've had to delete a few posts from this thread due to off topic comments that were not appropriate. Let's try to stay on topic, this is a good discussion, I'd hate to have it locked
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Re: What do the numbers on contra/torque springs mean?

Post by mwilliamshs »

Wheelman-111 wrote:Greetings:

1. +1000, +2000 refers to the delay in shifting behavior compared to stock RPM.

2. No one knows. Measure according to my post with a bathrrom scale to obtain a spring rate in Kg./cm. or lbs./inch. The measurement that matters is within the length range of the spring mounted in the pulleys.
Thanks.

Mine rides so smoothly I never feel what I'd consider a "shift." I have nice linear acceleration up to 37ish mph and throttle response is good when speeding up from say 10 to 30, etc. My bike feels exactly as I'd expect a 50cc with a 210lb guy on it to and frankly it impresses me on the bigger hills in my area, one of which has a stoplight at its base I'm often taking off from and make the top at over 25 mph, which means I'm rarely passed by any but the most aggressive drivers.

I don't have any problems I'm trying to solve, just hoping to keep a similar attitude after a gear change.

It still seems to me these springs would be rated in lbs or %'s, since it's torque, not rpm, that exerts force on them. I mean, they're not centrifugal like clutch springs or roller weights...

Hard to believe in all of the time and $ I see spent on these scoots nobody's published stock part specs.

Anyway, thanks again. I'll just keep trying to wrap my head around it. No mods are likely till after my savings for the coming semester are complete. Gotta keep my 'eyes on prize' so to speak and so long as the scooter doesn't need repairs I shouldn't be spending $ on it.
Last edited by mwilliamshs on Mon Jul 06, 2015 6:43 am, edited 1 time in total.
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Re: What do the numbers on contra/torque springs mean?

Post by mwilliamshs »

curtis966 wrote:It's as simple as putting a stock contra and stock clutch with stock springs in and looking at your tach as you twist the throttle. When the clutch engages that's your answer for clutch springs. And when you feel it "switch gears" as its called that's the ratting for the contra. Done

Wish I had a tach! LOL
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Re: What do the numbers on contra/torque springs mean?

Post by patthesoundguy »

mwilliamshs wrote:
curtis966 wrote:It's as simple as putting a stock contra and stock clutch with stock springs in and looking at your tach as you twist the throttle. When the clutch engages that's your answer for clutch springs. And when you feel it "switch gears" as its called that's the ratting for the contra. Done

Wish I had a tach! LOL
I have one of those $10 digital tachs from eBay. It works fairly well, all you need to do to hook it up is wrap the trigger wire around your sparkplug wire and set it to single cylinder 2 stroke mode and enjoy. It's totally self contained with an internal battery. I have a couple of them. I like to pull the cover off of the trans and watch the action of the variator and the driven pulley. You can look at the tach and see when the driven pulley starts to split and the variator working all at the same time. Just don't get too close and loose a hand or finger in the moving transmission parts! To sort out my aero 80 contra spring I rode around with the cover off to see it work under load.
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Re: What do the numbers on contra/torque springs mean?

Post by Wheelman-111 »

Greetings:

If you're thinking "shift" like a manual transmission going from 1st to 2nd (or 1st to 5th, for that matter, that's not how a "Continuously" Variable Transmission works. Consider the following:

You apply throttle off idle. The engine revs up a bit, then the clutch bites, and you scoot off into the sunset. As you go, if you keep an ear to the engine note (or an eye on the Tach...) you'll find that the engine speed climbs ever so slowly, while the wind in your (hopefully helmeted) ears increases much quicker. How's that? The groundspeed is climbing quickly from 5 to 35MPH, but the engine seems planted between 7500 and 8000 RPM? (depending on your state of tune) The groundspeed increases much more than the engine RPM. That's the belt shifting, crawling in a very slow walk up the pulley sheaves to the rim of the front pulley and diving down between the back pulley sheaves, "shifting" over the course of your accelerating ride. If you back off throttle, and thrust decreases a little, the cam in the rear pulley will then drop the RPM about a thousand or so as the belt is forced deeper out back by that cam action. If you twist throttle back on the cam raises the belt away from center and the RPM jumps up about a thousand. But your groundspeed stays at 35. That belt is "shifting" continuously, all the time.

Flash 7 was set up to crack 10,000 just off-idle, at maybe 15 MPH with the throttle pinned. From there it rose to 10,500 or so at full pulley spread, by which time I was going about 65. If the wind was right and the right jets installed, the speed AND the RPM would then climb together, linearly up to whatever top speed the Wind and Hill gods allowed.

So the proper stiffness of spring, along with the corresponding weights, keeps the engine singing its happy song at maximum power throughout the range. Stiffer spring makes it maintain a higher RPM. Softer spring a lower note. Get the spring right for your particular application, then fine-tune with the rollers, just 3 grams (total load) at a time to get it perfect.
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Re: What do the numbers on contra/torque springs mean?

Post by patthesoundguy »

Wheelman-111 wrote:Greetings:

If you're thinking "shift" like a manual transmission going from 1st to 2nd (or 1st to 5th, for that matter, that's not how a "Continuously" Variable Transmission works. Consider the following:

You apply throttle off idle. The engine revs up a bit, then the clutch bites, and you scoot off into the sunset. As you go, if you keep an ear to the engine note (or an eye on the Tach...) you'll find that the engine speed climbs ever so slowly, while the wind in your (hopefully helmeted) ears increases much quicker. How's that? The groundspeed is climbing quickly from 5 to 35MPH, but the engine seems planted between 7500 and 8000 RPM? (depending on your state of tune) The groundspeed increases much more than the engine RPM. That's the belt shifting, crawling in a very slow walk up the pulley sheaves to the rim of the front pulley and diving down between the back pulley sheaves, "shifting" over the course of your accelerating ride. If you back off throttle, and thrust decreases a little, the cam in the rear pulley will then drop the RPM about a thousand or so as the belt is forced deeper out back by that cam action. If you twist throttle back on the cam raises the belt away from center and the RPM jumps up about a thousand. But your groundspeed stays at 35. That belt is "shifting" continuously, all the time.

Flash 7 was set up to crack 10,000 just off-idle, at maybe 15 MPH with the throttle pinned. From there it rose to 10,500 or so at full pulley spread, by which time I was going about 65. If the wind was right and the right jets installed, the speed AND the RPM would then climb together, linearly up to whatever top speed the Wind and Hill gods allowed.

So the proper stiffness of spring, along with the corresponding weights, keeps the engine singing its happy song at maximum power throughout the range. Stiffer spring makes it maintain a higher RPM. Softer spring a lower note. Get the spring right for your particular application, then fine-tune with the rollers, just 3 grams (total load) at a time to get it perfect.
Man I love this post! So informative and super clever as always :thumbwink:
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