Re: Lets pool our contra spring knowledge!

Lol, I got 5 on it.

Re: Lets pool our contra spring knowledge!

Coward.

Pics. It's so much stronger now than stock.

image.jpg
image.jpg

Re: Lets pool our contra spring knowledge!

#CrazyWayne™ rocks. #CrazyWayne /

just cut an offset retainer on your lathe to run a taller spring.

Re: Lets pool our contra spring knowledge!

Ha! Fucking pay up buddy.

Rules! Didn't change a thing with vari setup.

Did over rev at first like all dual variated bikes, then settled about 500-1k below that. Then held it all the way up.

Pow.

Re: Lets pool our contra spring knowledge!

#CrazyWayne™ rocks. #CrazyWayne /

Two bits you love me long time

Re: Lets pool our contra spring knowledge!

We want a shorter spring Wayne. Not taller.

If the spring and clip hold up this works awesome.

Only drag is that I have more travel on my modded hobbit pulley, but now I could play with the camino pulley a bit. Maybe can modify it for mo travel too

Re: Lets pool our contra spring knowledge!

See, now comes the real question.

Who here is man enough to try this?

Risking cutting a stock spring?

I bet very few.

And that makes me depressed.

Life is risk.

Re: Lets pool our contra spring knowledge!

Hey man, success is worth $5 to me! Glad it worked out.

Re: Lets pool our contra spring knowledge!

Screw that, im slicing my spring. My kitted hobbit won't be together for about a week, but I'll do it after a couple rides so I get a feel for the stock Camino pulley. Need a constant before a variable.

Also got some weird springs laying around from the progressive spring mod I could try. Never modded the pa50 pulley for more travel, so I won't be losing much.

Re: Lets pool our contra spring knowledge!

I couldn't fit any helper springs in with this.

No room

Re: Lets pool our contra spring knowledge!

Measurements across pulley with stock belt.

Belt at highest point possible on rear modded hobbit pulley 111.5mm

Highest point possible on camino pulley 106mm.

It's possible to mod the camino for more travel,

But I'll need a very deep small cutter for the lathe. It's pretty much

super difficult to mod the camino for more travel.

Ill try this camino on my hobbit for a bit. Just to see how it does.

I bet I'll switch back to the modded hobbit pulley tho.

All this is moot anyways since motomatic is modifying

those giant gy6 pulleys for hobbits and I hear they rock.

Re: Lets pool our contra spring knowledge!

Thats discouraging. Let me know how it works out. Guess I'll grind the rivets off a spare pulley while my bike's being painted, lol.

Re: Lets pool our contra spring knowledge!

Hello guys, greatings from Norway.

Here is my experience with stiffer spring in a rear Camino pulley:

I use the lowermost spring on the picture, this is the strongest spring i could get hold of that would fit.

I bought my springs here:

http://www.industrial-springs.com/

If you buy it elsewhere, you can use compression strength showed in picture above, and find the exact spring.

I had to grind a little bit to make it fit inside nr 15 on this picture:

I use 40,1 gram weights in total.

The moped is really nice an smooth now. I love it.

Its accelerate smooth all the way up to top speed with a stable torque.

The best is that it even accelerate nice up hills. Before when it was down shifting

it was really difficult uphills, because I was loosing the powerband when downshifting and it would go slower

because of this. Now i can loosen the throttle push it again and go straight up to the best powerband

No downshifting.

This setup is highly recommended for all of you guys with TJT vario and the new type (EU style, camino or what ever you call it) rear vario.

:D :D :D :D :D

I just want to add on that my camino is tuned with a light setup.

65 cc, proma exhaust, TJT vario, new rear spring and a small upjet. (edited)

Re: Lets pool our contra spring knowledge!

Thx!

Re: Lets pool our contra spring knowledge!

Great info, thank you!

Re: Lets pool our contra spring knowledge!

But what we really need is for you to find the same spring thru Century spring corp....then we could get em easier.

But that wouldn't be metric measuremènts.

Is there a part number for the one you got so we can cross reference?

Oh never mind. Saw it.

Re: Lets pool our contra spring knowledge!

I have found 2 springs that looks to be very similar to my spring.

You can see here that there is also stronger springs that will fit our pulley here:

Taken from here page 201:

https://www.centuryspring.com/pdfs/12-228COMPRESSION.pdf

As you see I have compared the springs with my numbers at bottom of picture.

I am not sure about how heavy weights you guys are running with. But my experience is that more strenght on the rear spring heavier weights are needed.

So for you guys that have more power than me and wants to experience with stronger springs. You also need to buy heavier weights. 7,8,9 or even 10 grams per roller. Could be more, but just be prepared.

Hopes this helps you guys!!

Re: Lets pool our contra spring knowledge!

When I was trying to find the right setup I tried allot of different weights. I had to try MANY different setups before I was happy with the result. Here is what I used:

I also made this spreadsheet, so I new what rollers to use next:

You can download it from here:

https://mega.co.nz/#!TMtH3JxK!AgXc2FBwZQP3VorCCWFYWosPYWnl73W0xceklTNb_Mk

Re: Lets pool our contra spring knowledge!

Ha! Sweet.

Personally, I try to go with the lightest spring possible

without dropping rpm with full travel.

So as long as you find springs that fit in the camino pulley that react at different rates, Folks can choose their flavor.

Some of us crazy folks even get a stiffer spring then grind down the outer edge

to change the spring rate to be more progressive.

It works!

Re: Lets pool our contra spring knowledge!

Personaly my experience, I would not go lighter compression strenght then this. But thats my experience. I have tried all 4 springs i showed you guys in earlier post, and all of the three other ones made my camino downshift in the wrong powerband. I tried then to compensate with less weights, but then my bike had way to much rpm before it started to variate, and it made my bike slower from start.

All this is my experience. And it all depends on where you got the best powerband. Different exhausts would probably give powerband in different rpms. So you have to fine tune it with weights.

My experience is also that with more strength in the rear pulley, easier it is to fine tune it. But you need allot of weights to make it happen. And you also need heavier weights. You can compare this with tuned scooters, they also run heavier weights and stronger springs.

Sorry for my bad english :)

Re: Lets pool our contra spring knowledge!

#CrazyWayne™ rocks. #CrazyWayne /

If the spring is to stiff your loosing power do to the belt being to tight.

I find it best to if the belt can o most slip or slips just a pinch.

Re: Lets pool our contra spring knowledge!

Well that is not correct. STiffer spring does not mean tighter belt. But you need mor force to move/variate. But if you compensate with more weights in front you get more force to variate.

The only problem I have had with to tight belt, is that it not variate all the way, and you loosing top speed. But not power.

Another thing, stiffer spring in rear means more grip on the belt on the rear pulley, this means that you actually can losen the belt more without loosing the grip. (edited)

Re: Lets pool our contra spring knowledge!

This is taken from a scooter forum;

First things first, this info assumes you know how a CVT works.

The job of the contra spring is to maintain appropriate tension on the drive belt, raise the belt up the rear pulley during deceleration, and balance the force of the roller weights to maintain the RPM range in which the gear ratio of the CVT varies. Here's how: When torque is applied to the front pulley, the roller weights cause the belt to rise, increasing the gear ratio of the pulley. Since the belt is a fixed length, the reciprocal action is that the belt must be pulled down towards the center of the rear pulley, raising the gear ratio simultaneously in the rear. The contra spring resists this force, creating a balance at a certain RPM range. Why is this important? The roller weights can't be too light or too heavy in relation to the stiffness of the contra spring. If you go too light on the weights, top speed will suffer. If you go too heavy on the weights, acceleration will suffer.

The contra spring also helps climb hills. As previously explained, torque from the front pulley raises the gear ratio and compresses the contra spring when accelerating. The reciprocal action happens when you climb a hill. Resistance is applied to the rear wheel, the bike slows down, and the contra spring pushes the belt back up the rear pulley until it reaches a ratio that provides enough torque at the rear wheel to climb the hill at that RPM. The engine RPM's change relatively little as the scooter slows down because as the gear ratio decreases, the scooter will travel slower at the same engine speed. If your RPM's drop dramatically and your engine starts lugging, you need a stiffer contra spring.

Here's a YouTube video of a weak contra spring demonstration...

Contra springs also put you in a lower gear ratio when you roll off the throttle or hit the brakes. The variator is doing the same thing as when you climb hills, only caused by change in throttle input and/or braking rather than change of slope of the road. The "coasting" effect upon roll off comes from the fact that the pulleys are still being turned during deceleration, even though it's from rolling along. This limits how fast the contra spring drops the gear ratio back down. I suspect the reason stiffer contra springs are billed as "performance" items is because the added resistance increases RPM's and theoretically would inherently decrease any lag time in sudden downshifting... say from riding very fast in a high gear ratio, slowing suddenly for a corner, then needing to accelerate hard back out of it. I image the trade off, after a certain point, would be excessive heat/friction losses, belt wear, and limited top speed.

Re: Lets pool our contra spring knowledge!

Here is the same answear on another forum:

Re: Lets pool our contra spring knowledge!

Terbo Speghetti /

Thread resurrection!

Just bought a few springs from Century to play with, but I'm afraid they're gonna end up way too stiff. My brainless math tells me I'm looking at about 100 lbs/in. Anyone wanna call me stupid? Or am i a genius with a super fast hobbit now?

Re: Lets pool our contra spring knowledge!

Grind or sand the outer edge of the spring to weaken it. Flatten the outer side of the wire.

It works great. Just try not to get the spring too hot in this process

It won't break.

Re: Lets pool our contra spring knowledge!

todd amundson /

> Born to be WillD Wrote:

> -------------------------------------------------------

> wire diameter on most is 4-5mm depending on stiffness

>

> GY6 50 and the big ones

>

> Inner diameter: 48.5 mm

>

> Length: 154 mm

>

> The shitty China "GY6-50" but really QMB139

>

> Inner Diameter 49mm

>

> Length: 106mm

>

> Zuma/Jog Minarelli

>

> Inner Diameter:44.0mm

>

> Length: 108.0mm

>

> Zuma 125 4strokes

>

> Inner Diameter: 54.5mm

>

> Length: 116mm

>

> This site has a lot listed

>

> http://www.koso.com.tw/products-detail.php?id=252&lang=en

What the hell am I supposed to do with all these inner diameters and no external? Sure we can do the math based off your coil thickness but it makes more sense to list the shit for idiots like me while you’re in there. Thanks

Re: Lets pool our contra spring knowledge!

I forgot all about this endeavor

Re: Lets pool our contra spring knowledge!

IMG_20170927_114937.jpg

Just use a stone on your die grinder to grind it flatter in the center of the spring and then place a wood dowel or Hammer handle to the spring and hold it up to a bench grinder to take Material off the outer edge till you get the perfect spring

Re: Lets pool our contra spring knowledge!

Exactly. Boom

Always want to leave it a touch too strong so it'll settle in.

If you need it stronger afterwards,

Cut the spring length and add a spacer to take up the extra gap as I showed up top

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