on my 50v with AV10 motor and er3 variator and er86 clutch pulley.
could my belt be slipping? its a malossi and seems a little too wide for the clutch pulley whats a good belt to use with the doppler stuff? or has anyone else had this problem and can offer a solution? (edited)
ive done some searching and see its a variator bounce.
im using the stock counterspring slightly stiffened a la rebel moby mod rubber tube with bolt but not tightened much.
That’s the goat. It’s gonna buck you off like a goat would.
It’s from a weak engine spring.
Strengthen the spring or replace,
And/or get a launch lever to hold the engine in position better so it doesn’t bounce.
Also if your silentbloc rubber dingus bushings are shot, it will do this.
thanks for the advice. i did have the maximum weight (provided) attached to the er3.
so to my thinking there was too much sprung effect to allow the belt to move outwards engine backwards and cheeks in. so i took off all the weights and of course it didnt variate. i then reduced the strength of my counter spring to stock and it still wouldnt variate. i added weights slowly until it did start to variate at high revs only.
this was on the stand. ive yet to try it on the road.
isnt it all about getting a balance between the weights attached and the strength of the spring?
to my thinking if my spring had been any stronger i would have needed even more weight to get it to variate.
unless im missing something?
The goat happens because too little spring.
Engine shouldn’t bounce
Fixed possibly by lighter weights stronger spring or launch lever to stop bounce with your foot.
Yeah you have to tube it to achieve that balance.
Sometimes if it bounces you just need more spring, period. They sell aftermarket springs or you could mod your frame like I did to use a scooter contra spring. It’s the perfect solution to all moby spring issues. So many choices in springs to try for cheap
thanks for that jbot
that looks like the way im gonna go
i do like cheap
i removed the stiffener to the std counter spring and removed all the weights from the er3 variator. it wouldnt variate. with one weight on each arm and it wouldnt variate. with 2 it will variate but noit fully but the goat has gone away. ill add just enough weight to get it to variate fully and see if it does the goat. ive ordered a zuma spring and some bits to make a better contra set up.
I prefer the lighter scooter contra springs like malossi white to yellow usually and control most of the shifting with my foot on the lever and the left hand controlling the shift lock
If you like getting weird and experimenting, check out some of the threads on adding a gas strut. I haven't tried it but it might work for ya. You can in theory run a lower pressure but get some damping to prevent the bounce
yeah i dont mind getting creative
im wondering if the damper from a cars rear hatch would work?
> Alan Jackson wrote:
> -------------------------------------------------------
> yeah i dont mind getting creative
>
> im wondering if the damper from a cars rear hatch would work?
It may, but they are typically far too strong to use as a contra. You can buy them straight from McMaster for very little money, and in he throw/weight you need.
From my memory, I think 20-50 lb struts were the nominal range for a bunch of folks, dependent on setup
thanks for that graham dillon and jbot.
now to find the uk verion of mcmasters
btw my spring arrived
but just realised im gonna have to hack the original counterspring mount off the frame. i could save it and weld it back on at a later date if required but im leaning towards buying another moby and doing all sorts of modding hacking and welding to that and leaving this one near to standard.
If you search there are a few threads with sizes, weights, variator setup, pretty much everything has been figured out for ya. I think jbot tried one and went back, might be a good thread too, for some additional info.
thx graham, yeah jbot linked to his thread
it i think he initially used a gy? spring then went to a zuma/jog spring. which is what ive bought.
you are right, all of this stuff has been asked about before and is old news to most but i'm new to mobylettes and a bit of a noob. i find if someone mentions a solution i then use the search (not only on here) to find good info.
You want a 2 stroke Zuma or jog spring.
That one looks great.
It’s so much better, cut off that stupid frame mount. It’s such a dumb design. The contra style spring is perfectly aligned in the center of the engine to the frame. It’s as efficient as it can get.
Then you can adjust preload as well.
Personally every moby I get I’ll be taking that frame spring mount bracket off.
> Totally normal JBOT wrote:
> -------------------------------------------------------
>
> Personally every moby I get I’ll be taking that frame spring mount
> bracket off.
Sounds like you're ruining the collector resale value dummy!
HAha oh dear
im thinking i can hacksaw the (cheap) nylon bushes to give me the right amount of engine swing. ive got a threaded eye that will accept a roller thingy or bearing to ensure smoothness.
That’s good just cut em back enough for full travel. You need very little retainer to keep it on. It’s just stuck in there, you when you want to pull it out just take off the belt and pop it out
cheers jbot
On my reeded 50cc I used a 1000 spring, and in my very insane 70 I used a 1500 I think with a decent amount of preload.
Did u see my other insane moby shifter mod?
I added a notched shaft with a paddle shifter so it could have fixed gears. Was super fun.
Will be more fun once I put a kit on it
https://www.mopedarmy.com/forums/read.php?7,4261967,page=1
brilliant idea
my brain is doing somersaults trying to "invent" something similar
but for now ill copy your set up
im assuming theres no patent?
No ones cares about anything I make because they are afraid of change their rigid views on tuning.
So go for it if you like
my AV10 motor with std variator clutch (but with clutch starter arms removed) and std pulley and std spring work fine with my 82cc motor no goat. mallossi belt. clutch bite around 5000 rpm.
but when i fit an er3 and doppler clutch pulley er86 (modifield) and original spring i get the goat. so its the er3 variator that needs different spring specification.
i have made my own spring . i have 4 belts all different lengths. with shortest belt that compresses spring. i get zero goat. but no variation even with heaviest weights x 6. but with longer belts i get goat unless i remove all weights. and then the belt slips???
do i need to shape the belt so it fits the pulleys better? or will it wear itself into the correct profile after a while?
can you run the er3 without weights and get zero goat?
spring by alan jackson, on Flickr (edited)
Goat is just the motor bouncing
Do you have a launch lever yet? Make one then you can set your foot on it to stop any goat action and keep a weak spring. You might need a stronger spring if you bounce too much and don’t have any method of stopping bounce.
Or in combo with the lever you could add a vari brake like I have to control shift from a hand lever.
Btw, when using a scooter contra spring one often needs to use a strong spring. If that’s a malossi white spring it’s likely much too weak for 82cc.
The only way to use less spring force is with methods that stop the bounce via foot launch lever or hand varibrake
Lastly, have you checked for smooth motor swing with the engine not running? Just move the swing and make sure its not rubbing against anything. Seems silly to ask but diy swinging setups often have a carb or reed block or intake that will bump into the spring during variation. My goal is to get mine to have at least a 4mm gap so nothing gets rubbed or broken off.
Any resistance in the swing (sans spring) can cause weird issues.
You’ve inspired me to go ride a swinging engine bike today. I get so proud in French style bikes when I finally get all the geometry right and everything swings together without eating itself.
But I will say I’m constantly controlling shift on my setups, I could use a much stronger spring and have it all shift automatically but I’ve always felt that moby style bikes are semi automatic, with my preference being acting more like a manual shift (edited)
i checked swing and i have 32mm of swing with one of the tighter belts on and then it gets too hard to compress the spring anymore by hand, nothing fouling. its a purple or mauve pink spring. if you scroll up a few posts there are 2 pictures one with nylon bushes and one above that with with the name and number on it. nakaru -1000??
i will just keep playing adding weights and swapping belts until i find a good combo. if not i can adjust the spring and apply more preload. but a shorter belt sort of does that. i am getting belt slip. the er3 has lots of evidence of belt slip black marks. im scared of making a launch lever because im no good at doing too many things at once when im riding. like patting your head and rubbing your belly at the same time. but i might have to learn.
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