Tuning the Forza 300 CVT

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davenowherejones
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Re: Tuning the Forza 300 CVT

Post by davenowherejones »

aguim wrote:Problem is, there's only one (trans-mission) speed to play with on a CVT scooter. You let it
rev more freely at low vehicule speeds, and voilà it overrevs at high speeds (since it was
normally built to reach top revs at reacheable top speed).

I wouldn't fool around with these, just make sure they're properly cleaned/lubed every year or so.
(belt itself should be good for 30K -- Dave Jones is quite hard on his and has only changed it
once in 48K, so maybe 40K is possible for slower pokes like me?)
Honda says change the belt every 25,600 km, today I am at 48456 km, so I have another 2700 km to go.

I got tired of working today and talked to a few bikers at McDonalds. I dropped tools and went up the Coquihalla for a Samosa & Coffee. 120 kmph up hill and the samosa was good. Some twit dumped oil on a big bridge. Highways dumped sand and dirt all over it. What a mess but it was not slippery at least.

I changed a sprocket on my DR650 but I am not expert enough to have really noticed any difference. I have played around with tuning and I came to the conclusion that the results were not worth the efforts. Some of the factory engineers do get things right. You are always working with compromises. You increase speed but mpg decreases. You increase acceleration but reliability is compromised. Which tradeoffs do you want?

I am having more fun just riding the snot out of the Forza as it is. If I break it, I will buy something new.
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Re: Tuning the Forza 300 CVT

Post by davenowherejones »

I have had my Forza at 145 kmph under ideal conditions, tailwind, flat, long road BUT is the rest of motorcycle rated at 145?

Those small wheels are really spinning at that speed. Do we have a suspension rated for 145? Is the rider aware of his surroundings to safely go at this speed. And what if the little old lady pulls out to overtake the big truck.

I am too old and too worn out for that speed. Too many injuries and handicaps. Slow down and smell the asphalt. Or the cow shit if you live here.

I was recently riding bigger motorcycles at much higher speeds. I like my Forza better.
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E. Foster Salsbury
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Re: Tuning the Forza 300 CVT

Post by E. Foster Salsbury »

Stock rollers are 21 gram or 126 total.

According to BRed's research 126 (21x6) gram total gives a 5800rpm shift point.
90 (15x6) gram total gives a 7160 rpm shift point.
Halfway between those is 108 gram total (my selection 18x6 sliders) gives a 6480 shift point. Supposedly peak torque, and fuel efficiency is 6500?
See Ed's graph...

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Re: Tuning the Forza 300 CVT

Post by E. Foster Salsbury »

Also... Maybe Honda's engineers hands were tied by very, very strict emission standards?
I read that's why Honda went with a 279cc engine. Engines over 280cc had even more strict standards. Something to do with Euro 5 or 6 I think?
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Re: Tuning the Forza 300 CVT

Post by BRed »

A couple of runs that might be useful to those using simple single weight setups.....
these are single weight setups of various weights compared to DR Pulley 19gram sliders.


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Several things become apparent when you isolate a series of single runs....

1) you can see that the supposedly continuously variable transmission actually produces an almost sawtooth curve showing 3 distinct peaks for almost every roller combination tested. Sliders flatten the peaks so they're less obvious.

2) with the exception of the first two seconds of each run (which is ALL clutches...more on that later), every time you see the acceleration curve turns downward, it means your rollers are moving out TOO FAST and you're losing rpm! In effect you're losing the race by wasting hard won revs.

3) each of these peaks and valleys are of short duration...a couple of seconds each at most, but every rpm change, up or down, comes complete with requisite clutch slippage....the clutch pads slip worse during major rpm changes.

4) most of those setups still have one more upshift coming....it usually occurs well after the 1/4 mile run is completed but before redline is reached.
This is true for all but the lightest of weight combinations.





for those tuning for RAW power there is a very simple mod that will almost always gain you a second or two on your 1/4 mile time....
swap out your clutch springs!

In the name of driveabilty Honda has given you a very tame clutch setup....
they don't want Granny to pee her pants when she rolls on the throttle so they use very weak springs that engage at very low rpm.

If you ridden a bike with a standard transmission, you understand....
you can creep away from a stop, or you can rev it a bit and JUMP away from a stop or you can rev it a lot and burn rubber away from a stop.
Well, to a certain extent you can do the same with your scoot (ok, you might not burn a lot of rubber, BUT you can make it jump!)

both Polini and Malossi make spring kits for the Forza's CN-250 style clutch pack.
There are several aftermarket clutches available but these require a lot of experimentation and testing to setup properly.

What I suggest is the yellow middle spring set from the Malossi clutch tuning kit.
There's a white one (lower than stock), a yellow one (125% of stock) and a red one(150% of stock)...actually 3 springs of each weight.
These resist the outward force of the clutch pad flyweights.

here are a few graphs showing just the first 2 seconds of runs comparing stock springs to Malossi yellow springs
stock springs engage at ~4400rpm yellow Malossi springs engage at~4900rpm

by engaging the clutch at higher rpm, there's less loss of revs AND you're still closer the prime power band...
the effects on speed and Gee Force is obvious

remember the color of lines through the various graphs...
they show revs, speed and Gees plotted against time and speed plotted against distance


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Re: Tuning the Forza 300 CVT

Post by leoper »

BRed wrote:
What I suggest is the yellow middle spring set from the Malossi clutch tuning kit.
There's a white one (lower than stock), a yellow one (125% of stock) and a red one(150% of stock)...actually 3 springs of each weight.
These resist the outward force of the clutch pad flyweights.

here are a few graphs showing just the first 2 seconds of runs comparing stock springs to Malossi yellow springs
stock springs engage at ~4400rpm yellow Malossi springs engage at~4900rpm
do you think yellow malossi springs combined with 17g 23x18 drpulley sliders are better than only 17g 23x18 drpulley sliders ?
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Re: Tuning the Forza 300 CVT

Post by leoper »

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Re: Tuning the Forza 300 CVT

Post by sesdave »

I finally got round to putting 3x15gm malossi rollers with 3x19gm sliders in my Forza. Whilst the acceleration is good fun upto about 120km at about 7500 rpm showing on the dials ( unless my speedo and tach are giving me incorrect readings ) it struggles to go any higher. I thought I would get my topend back with this combination not lower than using 6x17gm sliders. Is the problem that the combined weight is still 108gms which is where I lose the topend? Any suggestions appreciated. I will probably keep the combination for the next month as it is enjoyable to drive even if I haven't got more topend. Over here 120 is probably enough anyway to stay alive a bit longer lol
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Re: Tuning the Forza 300 CVT

Post by E. Foster Salsbury »

I would think that wear of the belt and rear tire would affect top speed more than the 108 gram total weight.
How much milage on both of these?
What size rear tire you running?
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Re: Tuning the Forza 300 CVT

Post by sendler2112 »

Install all 6 sliders to get the highest top speed back. Check the wear pattern to see if the variator is capable of compressing enough to move the belt all of the way to the outer edge.
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Re: Tuning the Forza 300 CVT

Post by BRed »

Sesdave:
Malossi rollers are a little undersized as far as diameter (usually 23.0mm) so about .25mm smaller than Honda OEM?
If sized properly when installed the sliders should rattle a bit as the 3 rollers are supporting the moving face when the variator is fully closed AND fully open.

Honda rollers for the 250cc scoots are the tallest....every supplier varies in diameter a bit, so you have to measure them to be sure.

I still like the super hard carbon fiber rollers best for use in a combination, since they get slicker with use.


Glad to see Photobucket released everyone's photos from the Gulag..... :)
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Re: Tuning the Forza 300 CVT

Post by justbuck1 »

Do you have any experience with Adige HRS (slider weights)?
http://www.adige.eu/public/ENG/products ... t-kits.asp
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Re: Tuning the Forza 300 CVT

Post by BRed »

I have a set of the 23 gram HRS carbon weights, but have never tested them with the Veypor....
I'm saving them for a future test.

since the HRS weights are actually a cylinder with 2 slightly flattened spots as opposed to the rounded polygon shape of sliders, they would not work in a combination but they "should" give a performance gain being somewhere between sliders and rollers and that's a good thing!

The ones I have are HEAVY...23gr each. They are also way < 23.0mm across the flats so they should yield an extremely low starting gear, like sliders.



Again, for those who want the simplicity of single weights...

use 6 x 17 gram rollers or 6 x19 gram sliders for peak acceleration
or
use 6 x19 gram rollers or 6 x20 gram sliders for commuting/touring.

the shape and actual diameter rollers vs sliders are such that there are about 2 grams of weight difference to get similar results.


the guys running a properly set up combination will catch you! :)
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Re: Tuning the Forza 300 CVT

Post by Kompact »

What is the best performing variator? I was looking at https://scooterpartsco.com/malossi/01-m ... 397077cef1

I want to keep my bike reliable but would also like better acceleration. I currently have 18g Dr Pully Sliders, everything else is stock. That makes it way better than but I would still like more off the line and I'm wondering if the best option is a new variator.
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Re: Tuning the Forza 300 CVT

Post by BRed »

Kompact, with your current setup, what is your 0-100kph time (roughly) and what is your max comfortable cruise speed (not pegged throttle speed)?

I have direct experience with DR Pulley's slider based variator, the JCosta traverse pin type variator, and both Honda variators (single track and dual track Reflex type) on my own bikes and I've installed both Polini and Malossi variators on others bikes.

Beyond any doubt (and I have graphs to prove it!), the JCosta yields the greatest gains across the entire useable range.... over any other type I've tested. All of them show gains at bottom end but usually come with light weights to insure that fact.

You may end up tuning your performance variator to gain more top end or to try to reduce revs at top end. And then there's the reliability issue...it seems the more extreme the performance gains the more extreme the wear and tear on that particular component....high performance variators on even moderately powered scooters of 20HP or so, that are routinely run at interstate speeds for long periods of time, tend to have very short lives and often go out with a catastrophic failure called "grenading"!

The only aftermarket variators I know of that are still in use after extended running all had one thing in common....
they came with 2 (TWO) pulley faces.

I would not buy anything else since I believe the mismatched pulley faces running under load at high speed is the root cause of "grenading".

I've yet to see a Honda variator with enough wear on it to warrant replacement....
I have personally worn out two aftermarket variators in ~10,000 miles!

Stick to the OEM variator for max reliability but don't be afraid to play with the weights.
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Re: Tuning the Forza 300 CVT

Post by Kompact »

BRed wrote:what is your 0-100kph time (roughly) and what is your max comfortable cruise speed (not pegged throttle speed)?


Stick to the OEM variator for max reliability but don't be afraid to play with the weights.

Never really counted 0-100, rough ballpark guess if I picture it in my mind and count .... 5-7 seconds...ish? Comfortable cruising speed is 120 at about 7rpm, engine doesn't feel stressed.

I'll stick with the OEM variator then, reliability is more important than performance. I'll try some lighter sliders, I seem to remember putting 18's in, maybe they are 20's, I'll have to open it up and check.

Thanks for the info BRed.
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Re: Tuning the Forza 300 CVT

Post by sesdave »

So what do you think will work best. With the 15g rollers and 19g sliders very nice acceleration but struggles for top end. So do I either put in 3x 17g and 3x 19g slider mix or just 6x19g. I have a set of both.
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Re: Tuning the Forza 300 CVT

Post by BRed »

In saying it "struggles for top end", you are, in effect, saying you need to increase your 3 heaviest weights....
if running a combination, you would need to go to something like 3x21g sliders and 3x15g or maybe 3x14g rollers.


of course, you can also regain top end with 6 x19g sliders, but you already know from your testing that it will not accelerate nearly as fast from a stop as a slider/roller combination....
bite the bullet and bump the 3 heavy slider weights up a gram or 2 each. :)

unfortunately mixing 2 slider weights changes only the shiftpoint but not the shape of the acceleration curve, which is the whole point of combining weight types.
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Re: Tuning the Forza 300 CVT

Post by sesdave »

Took the forza to the honda garage intent on trying out the 17g and 19g mix of sliders. Discovered 2 things that were probably affecting my topend with the 15g roller and 19g slider mix - its was hard to get the revs higher than 7500. The previous mechanic had put the sliders in the wrong way round and the clutch bell and pads were more worn and shiny than my old bald head. Got the mechanic to change the clutch parts and put the sliders in the right way round. Off on a trip on Monday so will see if I have now got my topend back with the 15g and 19g slider mix. If not back to original plan lol.
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Re: Tuning the Forza 300 CVT

Post by BRed »

You know, I ALMOST asked if you were 100% sure the sliders were installed right!
With an embarrassing lack of top end while using sliders of any weight, that's always the cause.

It just didn't sound right for the range of weights you were using...
with sliders you can almost bet on the fact that any mechanic will install them wrong the first time round (unless he reads the instructions?).

If you use sliders it's up to you as the owner to make a visual inspection that the mechanic does it right, tall side up...
if you don't, he won't! :)
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