Been checking out and reading about variators, found what I might like make by Teknnoetre on WIKI , but only found an obscure Italian video. Any help out there?
even the malossi is way better than that crap... what are you on about?
Well, I mentioned in another post I just wanted to tweak my speed , been trying to understand how they work before posting. I think that heavy weights are not what I need, but if I switch to an 8 roller variator ,from my Bravo 5 roller, it might be what I need. Using the same stock weights
Only linked the 8-roller because I know that's what he was referring too.
8 roller's aren't worth it. Get the Malossi for less money and enjoy.
What's the problem with 8 rollers Dirty?
It's the exact same design as the stock variator, just with more weights.
IT uses the same odd-sized weights as the 5 roller. The malossi/polini utilize common 16x13 rollers so you can get different weights to tune your transmission. The unit itself is also overly heavy and complicated compared to either of the others
I think the 8 roller has weird sized weights, the aftermarket variator use the 16x13 weights. Same size as the 50cc gy6 scooters, they are cheap and come in abundance of different weights. They are also 6 roller so you can do 3 4g and 3 5g.
Thanks guys, so ill check out the Malossi, also the weights are easy to find for this aftermarket from what I'm reading.
If your going to spend the money go with the polini. IMO the curved ramp plate works better than the flat one the malossi comes with, I didn’t really care for my malossi variator. If you buy it today you can get 20% off at treats.
Here's my setup, for what it's worth. 1978 Bravo, fast model, with the higher geared transmission. Dellorto 13.13 carb #69 jet. Proma Circuit pipe. Malossi hi flow filter. Polini Variator, Malossi belt, and 90mm rear cheeks (soon to be 100). White contra spring. Why white spring with stock engine? I'll explain in a sec. Currently running all the heavier of the weights. Top speed is currently 35-36 on the flat.
When I put the Polini variator on, I fooled around with the weights, and found that using half of the heavy, and half of the lighter weights was optimum for top speed and take off, with a top speed of 38. The problem was, with the factory contra, the RPM's would vary while accelerating, especially when accelerating uphill. It was like playing a guitar chord with a whammy bar. Wowwaaawowwaaawowaa. It would eventually level out as speed increased, but I couldn't get consistent, smooth acceleration. so I thought that changing to a stiffer contra spring would prevent the rear variator from fluctuating so much. It did, but with half heavy and half light weights, and the white contra, it wouldn't variate fully, and I could only get about 30-32 mph. So I put the heavy weights in, and now I have consistent acceleration, good hill climbing ability, and a top speed of 35. It's not quite variations completely, but I'm happy with 35 and I like the torque.
I bought 100mm cheeks from Eric, and treats has a special belt for using 100mm pulleys, so now I will have more low end, and more variation IF I have the power to variate it fully. Looks like I will have a bunch more fooling around with variator variables. Oh yay.
> Seth B Wrote:
> Here's my setup, for what it's worth. 1978 Bravo, fast model, with the
> higher geared transmission. Dellorto 13.13 carb #69 jet. Proma Circuit
> pipe. Malossi hi flow filter. Polini Variator, Malossi belt, and 90mm
> rear cheeks (soon to be 100). White contra spring. Why white spring with
> stock engine? I'll explain in a sec. Currently running all the heavier
> of the weights. Top speed is currently 35-36 on the flat.
> When I put the Polini variator on, I fooled around with the weights, and
> found that using half of the heavy, and half of the lighter weights was
> optimum for top speed and take off, with a top speed of 38. The problem
> was, with the factory contra, the RPM's would vary while accelerating,
> especially when accelerating uphill. It was like playing a guitar chord
> with a whammy bar. Wowwaaawowwaaawowaa. It would eventually level out as
> speed increased, but I couldn't get consistent, smooth acceleration. so
> I thought that changing to a stiffer contra spring would prevent the
> rear variator from fluctuating so much. It did, but with half heavy and
> half light weights, and the white contra, it wouldn't variate fully, and
> I could only get about 30-32 mph. So I put the heavy weights in, and now
> I have consistent acceleration, good hill climbing ability, and a top
> speed of 35. It's not quite variations completely, but I'm happy with 35
> and I like the torque.
I have always found I prefer having the lightest spring I can get away with. This requires lighter weights etc. so there is less weight/force to throw around.
> I bought 100mm cheeks from Eric, and treats has a special belt for using
> 100mm pulleys, so now I will have more low end, and more variation IF I
> have the power to variate it fully. Looks like I will have a bunch more
> fooling around with variator variables. Oh yay.
The 100mm plates will give you a lower end ratio (more torque) but they don't offer any more variation that the 90mm plates.
Hydra, I'm still trying to wrap my last surviving brain cell around this concept, and I know we've been over it before, and I'm sure not challenging your experience, but bear with me. From stock: front variator and rear pulley diameter are 90mm
If I install a larger front pulley, I increase top end.
If I install a larger rear pulley I get increased torque.
I have installed a larger front pulley, Polini variator. Pulley diameter is 100mm. However, it can only variate to 90mm because of belt length. So full variation is the same as original.
If I install the longer belt from Treats as is, it would be long enough to slip off the 90mm rear pulley. BUT if I change the rear cheeks to 100mm to match the front pulley cheeks, then the special longer belt won't slip off the rear.
So with the 100mm Polini variator and the 100mm rear cheeks installed, at zero variation I will be lower geared for more torque, but at full variation (to the full 100mm diameter) the front pulley is now larger and I should get more top end also, if I have enough power to variate to the full 100mm. Meaning by changing BOTH pulleys, I should gain on both ends. That's how I understand a CVT.
The polini and malossi variator all have modified cheek angles, which allows them to provide more belt travel as they open and close.
Without changing cheek angle, you are limited in variation by the in and out travel of the cheeks. The 100mm pullies move the belt the same distance/amount as the 90, but just start and end at a wider diameter.
The CNC plates seems to follow this and allow more variation as you are discussing, but the stock Euro 100mm plates are clearly limited to how LOW they will allow the belt to ride.
With a set of CNC plates and aftermarket variator, you could get a little more low end in addition to the top end, but not as much as you gain by changing physical gearing in the trans.
Another thing to check is push the variator pulleys together and set your belt between the 2 I’ve seen the moveable face of the variator bottom out on the stationary face before the belt reaches the top.
You can modify variators and rear pulleys for more travel, I do it all the time. A lil shaving a vari at the boss (hub) might drop the deeper into the front, getting off the line faster. If said vari was shaved, it also can in theory variate the belt higher in the pulley at fully closing allowing faster top speed. This is dependent on many factors tho...spring tension, weight selection, rear pulley travel, etc
I see what you're saying now, about the in/out lateral travel being the limiting factor. Makes sense. I wonder if I will gain anything either way with the 100mm rear cheeks I've got coming from Eric. Sure I will, I'll gain education, experience, and practice changing shit around a hundred more times. And maybe a bit more torque so I can put the factory contra and lighter weights in.
the 100 mm cheeks give you a slightly lower starting ratio so you can dig out of the hole better, that is about it. i doubt you'll notice an increased range, as others have said that is determined by the front vario.
if you're not maxing out your range because your spring is too tight, you are leaving a lot on the table. look at the jbot threads, you can add shims and do lots of other stuff.
have you drilled out the adjustment hole so you can slide the engine back and forth? that bouncing sounds like a loose belt to me, but i dunno... i've never seen it on a vespa but i don't build high performance stuff... have seen it on 70cc peugeot setups.
It may be a loose belt. I'll open the slots up next time it's on the bench. I'm starting to wrap my head around all this. So many variables to consider. I know I'm leaving a little on the table with the white spring, but that up and down rpm bouncing was driving me batty. It sounded like a feral cat with the Proma!
there is a little plate welded on the subframe where the rear mounting hole for the engine bolts through. Two lil' spot welds, just pop it off with a chisel and you can finesse your belt tension. The rear pulley has a lil' more travel than the front so you can snug up the belt the same way you preload forks, plus it helps with starting and belt slip.
I know the spot welds you're talking about. I wondered why it was like that, with no adjustment. But I don't get what you mean by "snug up the belt the same way you preload forks" ? I've never done that.
So, first of all, I 100% agree with Polini variator. It changed everything for me. It changed the way my bike behaved, added low end, and made my bike so much more fun to ride.
I have a Malossi, and it's better than stock. The overall speed performance seems to be up there with the Polini, but it just isn't as good. It doesn't grip the belt as well as the Polini, and when it slips it is harder to start your bike. Just my experience.
I have a Motzing Special that I'm excited about, but I haven't had an opportunity to try it out. It looks good though.
I also run half and half weights in my Polini, but always the stock contra. That seems to be the best mix for me so far.
I been reading a lot about the lighter springs and weights ,plus I replaced the transmission to a 9:1 ? Ratio. Also I pretty much copied Seth's build as we have the same Bravos. That's why I tried to find a 6or8 roller w/ lighter weights ,so I wouldn't get the weight & force Dirty mentioned. That's if I'm following you guys right. 8]
Just a basic basic basic break down. More to it than just this but here is a start.
Less power = more weight needed to fully variate
More power = less weight needed to fully variate
Factoring contra into play....
Stiffer spring = more weight needed to fully variate
Lighter spring = less weight needed to fully variate
Jbot has a whole thread about contra spring weight and such.
https://www.mopedarmy.com/forums/read.php?7,3027947 . It is a good read. May help wrap your brain around contra springs and such. (edited)
I've changed some thoughts on this.
Now that custom variation ramps are being made (i.e. treats rumpus plate for hobbit TJT), it pretty much eliminates the need for strong springs on most builds. At this point, with a properly designed ramp plate, the spring is only really needed to stop slip. Just over slip tension is where you want to be.
I used to bang my head against a wall trying to get the perfect spring tension to slow upper range shift, but springs are a bad way to do that due to heat soaking and consistent softening that happens over time. Yes it does work, but it's not the best way. Stronger springs also eat power, which we do not want.
Ramp plate modifications are the best way to slow upper gearing variation to not overvariate past the powerband.
And frankly, now that I'm running manual control with dual variation, the whole damn issue is moot.
Full real time control over dual variation is the future. It's fucking amazingly so much faster than most automatic setups even with the best tune.
I'm stopped at fives points wondering which road to go. 8)
Yeah, basically an infinite amount of gears within a finite range.
The thing to remember is that changing pulley size, without changing anything else, will be just like regearing a chain driven rear wheel. And just like a chain bike, you will need a new belt, but the belt /chain is not the limiting factor
Tuning Variated bikes is an art based on physics.
Just dive in and start fooling around. You'll know when you're right and wrong. Just pay attention to the shift and try different variables one at a time.
> JBOT Admin Wrote:
> Tuning Variated bikes is an art based on physics.
> Just dive in and start fooling around. You'll know when you're right
> and wrong. Just pay attention to the shift and try different variables
> one at a time.
^^Yep! Only way to know, is try shit. Speculation changes nothing. So many variables to vary so it variates. A lot of different forces at work, and everything affects everything else.
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