Honda SWT-400 improved acceleration via my 4 slider CVT mod

When I got the Honda home the first thing next day was, I opened the CVT of the SW-T400 and checked the rollers. I found not 26 gram Honda but 21 gram Malossi.
Easy mod the previous owner did and made the SW-T400 respond well to the throttle and the rpm´s went high enough to have no problem with our 16% incline.

updated 2019-11-14

When I opened the CVT for the second time a week later 2 of the Malossi rollers went out and I am riding now with the 6 roller light Mustang conversion.

Not bad, not bad at all. But still a long way to go for my perfect mountain road tuning like I did with my 4 rollers and the spacer washer mod (see: The Canary Conversion - pushing the limits of sanity)
26 gram Dr. Pulley (now called Tech Pulley and slightly modified) are on the way to have my 4 roller Colt conversion back.

CVT mod

I installed 4x26gram Tech Pulley sliders.


The characteristic from the 2 piston 400cc Honda engine is a bit different to the one piston Piaggio engine I did this mod before. The Honda uses 8x 26 gram and using 4 x26 gram Pulleys turned out to be exactly 102 gram compared to 84 gram (half factory weight) from the Spidermax.
The Honda was running a bit higher rpm, but pretty much like the Canary Conversion on the Spidermax with around 7000 rpm at 120kmh.
The only issue I have with this setup is in the 30 to 60 km/h range the engine runs at 4500 to 6000 rpm. That was a bit too high for my taste on more or less a flat road.

To bring the rpm down in the low speed range I have to sacrifice the explosive acceleration a bit. I  tried 6x26g Tech Pulleys what work well in the 30 to 60 kmh range with 3500 to 5000 rpm while 120kmh is at 6500 rpm. But overall too sluggish for my taste.

With the Piaggio 460cc and 500cc the best configuration for extreme mountain roads worked better  by reducing the weights each of the 4 from the standard 21 to 19 gram and adding 0.7mm to the driving pulley spacer washer.
While with the 400cc twin 4 original weight sliders need some fine tuning.

Advanced CVT mod

I went the other way and added some weigh to the sliders and got a better result by adding 3 gram (the gold colored inserts) to each slider in the SW-T400.
The results were encouraging but in the 20 to 60 km/h area on very curvy roads it was still a bit too much rpm. At 120km/h the rpm dropped to 6700.

nearly there, lets try more weight ... and

I found MY ideal setting:

Remember, very hilly terrain with mountains up to 2500 meter, extreme long steep streets WHERE YOU LEARN FIRST HAND WHAT BREAK FADING IS. Combined with curvy mountain roads where 20 to 60 km/h is the max speed and the rpm changes nearly every second (so the sliders have a lot of sliding up and down the pulley to do). 
You also have the possibility of horse shit or other nice surprises in or directly behind the next curve, so sometimes even on a flat road you need very low speed to go into a curve.
Add near flat highways with 120 km/h max allowed.

I pressed another 3 gram ring into the 26 gram Sliders what fitted perfect in depth as you can see  ( the exact weight is 25.5 gram) so I am at 4x31.5 gram right now and NOW the 400cc twin cylinder Honda behaves exactly how I WANT IT.

Let me share the results in a 1400 km (and counting) test over any driving situation imaginable, single and with 2 persons including filled trunk and top box.

• steep hairpin curve 2 persons 15 km/h = 3500 rpm,  up to 4500 possible, when needed
• walking speed one person, legs stretched =2500-3000 rpm totally stable
• 20-60 km/h = 3500-5000 rpm, with passing a slow moving car on a short straight piece of road very fast since you are in an instant on 7000 rpm which is the the optimal torque / power point.
• from idle direct up a 16% slope with 2 persons = 4000 - 6000 rpm depends on the speed I want
• flat street from idle 1200 rpm onto an highway ramp 1st second WOT 5000 rpm 2nd second 7000 rpm. After good 100 meter the car on the highway frees the right lane and tries to pass me while I hit the highway with 110 and 2 seconds later pass the car with 128 (the real 120 according to GPS).  Then I fall back into the 120 km/h (speedometer) traffic at 6500 rpm. 
• with 2 persons, no noticeable difference an a flat street.
• no matter at what speed I rip open the throttle between 0 to 120km/h the rpm is never over 7000  
• 0 to 135km/h full throttle in 14 sec checked with GPS 135 is 125km/h real
• 30 to 100km/h in 5 sec
• gas millage no change to the 8 x 21 gram Malossi. 4.5 liter per 100km normal streets  and around 5.0 liter up in the mountains and a bit more on slow winding mountain roads. Or doing speed tests ;)
• aggressive driving style with lots of WOT 10% more at the pump for the fun.

It is kind of puzzling for me that to reach near identical performance and rpm while the one cylinder 460cc and 500cc Piaggio MASTER engine needs 4 sliders with 45%=76 gram of the original weight while the 2 cylinder 400cc Honda needs 4 sliders with 60%=126 gram of the original weight.
The same 126 gram setup with 6 Malossi 21 gram rollers shows a totally different character. More docile and not so flexible in the rpm band much less rpm control at the same speed.
So the whole magic is in 4 instead 8 pieces what move the pulley pressure plate.
The variator is stock not Malossi. Dr. Pulleys and Tech Pulleys work best with stock variators.

Can 4 rollers carry the weight from 8 without any problem?
Depends on the material they use, see: "warning bad Piaggio rollers".
I prefer the Dr.Pulleys or the Tech Pulleys because they are engineered to last and have no problem carrying the weight on only 4 sliders. Also the polymer lasts much longer than the usual rollers (up to 5 times)
Every year or 10.000km (6.000 miles) when you check on the pulleys switch them into the unused 4 slots of the pulley for even wear.
...and if they finally wear out, you use the 4 new ones you still have left.

left: Piaggio 500cc with 21 gram sliders, right: Piaggio 460cc with drilled out now 19 gram sliders. These are my original Dr. Pulley sliders which are from 2012 and around 20.000 km old. Just dirty nearly no wear signs. They would have much more millage on them but for the last 6 years I was doing kind of a "Lemony Snicket's A Series of Unfortunate Events" reenactment what prevented me mostly from using my scooter.

WHAT ARE THE BENEFITS?
- no more squealing from the belt
- no more flapping from the belt
- belt last (proven) longer (2 belts in 75000km with the second 4 pulley only belt is in near new condition after 40000 km - why? simple, every time you move from stand still and low rpm up the hill with the normal weights that puts lots of strain on the belt. Constant higher rpm´s and mostly close to the maximal torque band is easiest on the belt. See the Spidermax blog for proof.
- no more glazed clutch pads
- no more blue clutch bell
- spark plugs look like new longer
- Cylinder sides look like new after 75.0000km and piston top has a uniform burn image.

Cylinder and piston from the Piaggio 460cc MASTER engine after 75.000km

- engine runs much smoother
- instant clutch engage if needed (uphill) from idle to 5000 rpm in less than 1 sec.
- not more money at the pump with your identical riding style
- a happy bike and a happy owner (proven for 55.000 km with the Piaggio 460cc engine and also for 1500 km on the SWT-400 and counting)

WHAT IS THE DOWNSIDE ...and this is save for the engine???
I tested the 4 rollers and later slider setup for now over 10 years and over 57000 km and counting with out any engine problems.
 
Where did I get these special 3 gram rings?

Pretty much in every hardware store in the pluming section. Just look for these connectors and take the clamp ring out. They are for the 15mm permanent bendable white water pipes.
Cost for 8 rings below 8 Euros.

They cost below 60 Euro you can get them here:drpulley.info ...and no, I do not get any commission if you click this link.

How does it feel with the optimized Fliing Roller II sliders?
It feels kind like this:

Honda ST-T400 with Cessna Airplane on top shot at a roundabout (just retouched the stands from the plane and bike)

My Honda SWT-400 with Canary Conversion at work

Honda SW-T400 0 to 135kmh in 14 sec

Honda SW-T400 30 to 100kmh in 5 sec

Honda SW-T400 up a 6-16% incline

As you can see the scooter is mostly between 5000 and 7000 rpm. Why?
Simple answer because that is were you have maximum torque and are in the 60 to 95% power band. With my mod the Honda engine stays up to 120 km/h with full throttle always minimum 2500 rpm below the red line.
Here is the power and torque diagram from the older Silver Wing 400 motor,

 

The Dynojet power curve from the SW-T400 with standard weights and 8 rollers