Mecatecno Dragonfly

Introduction

Although this website is primarily about Electric Motion, the Mecatecno Dragonfly is initially what got me interested in electric trials bikes. 

I don't own a Dragonfly but I am in regular contact with someone who does.  The information presented here is a combination of public data, observations, and some reverse engineering.

Most of what I'll write about the Dragonfly assumes you have some familiarity with the way EM has done things.  If you are completely new to electric trials bikes, reviewing the EM sections will be helpful.

Some of the information I have found is inconsistent/contradictory.  As I learn more, I expect to reconcile all the differences. 

Advantages and Disadvantages

Overall, I think Mecatecno has the right idea - especially regarding the low weight.  The Dragonfly's battery, being held together with screws, looks far more serviceable than EM's.  The wiring layout is far better too - the motor, controller, and battery all connect in the same basic area.  Likewise, it has a much more accessible clutch than EM.  

The downsides are a non-linkage rear suspension and no place for any additional flywheel inertia.  And, of course, completely unknown reliability. 

The Dragonfly clutch uses 3 friction plates whereas the EM has 4.

Even though the rear shock is a high-quality Ohlins TTX22m.2 unit, it's intended for a bicycle application.  Assuming it survives the demands of moto-trials, I'm guessing it will require more frequent rebuilds than a standard motorcycle shock.

Although I would prefer to have the known quantity of a Tech front fork, the M4 fork is lighter.  The fact that M4 now employs a mechanical spring is comforting to me.

I expect this design will be more appealing to lighter/weaker riders than to heavier/stronger riders. 

You can find user manuals for the battery and Ohlins shock via mecatecnomotorcycles.com as .pdf downloads.

A Closer Look by The Hell Team

If you appreciate technical details, you will appreciate this excellent video by The Hell Team.  It is an “undressing” of the Dragonfly.

Dragonfly Assembly Video

Mecatechno produced an excellent assembly video for their special “dream bike” which has a claimed weight of just 54.2 kg (119.2 pounds)!  As of January 2024, the US price is $17,550 and only available by pre-order.

I have embedded the video below.   If you can, watch at a reduced speed to catch all the details.  My comments with timestamps follow.

0:15 We get the first glimpse of the beautiful welded titanium tubular frame.  That's not going to be cheap!

0:24 Here we can see the “gearbox” shafts on the work table.  Sponsor logos are featured prominently, among them is Dunlop. 

0:51 Heating of crankcase to install gearbox shafts.

0:54 Installation of the gearbox.  Note the paper gasket here (and for the clutch cover).

1:14 Front sprocket installed (at 2:05 we can count 10 teeth).

1:28 Clutch basket seems quite standard.  I'm estimating 75 teeth.    

1:33 Standard S3 clutch pack with 3 friction disks.

1:38 Notice 10 “clutch release arms” (same number as GasGas and others). 

1:53 Paper clutch cover gasket.

2:04 Filling gearbox with 75-weight oil.  Single plug for fill and drain.

3:14 Notice their work stand has been modified to accommodate a securing point through the footpeg.  This is because the skidplate angles up in front considerably.

 4:18 Ouch!  That steering stem nut got gouged. 

4:28 Controller (covered) being installed.

4:51 Motor installed using 3 screws.

4:58 Controller shown uncovered.

5:08 Beautiful carbon fiber handlebars.

6:39 Installation of the special lightweight battery (rated 1750 Wh).

6:42 Main fuse evident in the battery positive cable.

7:04 Display reads 38%, 50.0V, 31° C.

7:21 List of special parts.

Revised Overall Gearing Estimate

Based on observation, manufacturer claims, and educated guesses I think the following is close.

Secondary: 10T front sprocket drives 44T rear sprocket for a 4.4:1 ratio.  The chain size is 428.

Primary: 25T motor gear drives a 75T clutch basket gear for a 3.0:1 ratio.

Rotating the rear wheel and counting motor revolutions yields an overall reduction ratio of about 23.75:1.

This would put the transmission ratio at approximately 1.8:1.  (This is 3rd gear for a 5-speed Sherco gearbox.)

Thus, I'm estimating the overall ratio at: 4.4 x 3.0 x 1.8 = 23.76

A top speed of 28 mph has been measured via GPS.  This corresponds to a maximum motor speed of a bit over 8000 rpm using a standard trials tire.

It could also explain the US importer's 46 mph statement as a misprint of units.  28 mph is fairly close to 46 km/h.

For comparison, the EM Race (before 2024) had an overall motor speed reduction ratio of 14.39:1 and a measured motor maximum of 8,160 rpm.  This yields a top speed of about 70 km/h (44 mph) with the same tire dimension used for the Dragonfly calculation.

Firsthand Account

A friend (Mike) who is a current EM Race owner was able to obtain a brief test ride on the Dragonfly.  There was about a half meter of snow on the ground, so time on the bike was limited to the public road and owner's driveway.  The following information comes from that ride. 

By far the most impressive thing is the low weight.  Mike found it very easy to balance, and full lock turns were no problem. 

The controller has not yet been updated to the latest specifications and thus lacks the automatic anti-rollback, and also something I would call a virtual flywheel on deceleration.  Remote updates of the controller firmware are possible.

There is no “tick over” or idle feature.  It does not feel as though there is any automatic regeneration and there is no button to manually cause regeneration.

Mike said the throttle response was nice.  It may accelerate faster in the Green and Blue modes than Mike's 2022 Race.  He did not try Red mode.  There is no controller neutral.

The clutch feels about the same as the EM but was not adjusted to Mike's liking. 

Having not seen a drain plug, I was curious about changing the oil.  The oil comes out where it goes in.  Lay the bike on the left side to drain, and the right side to fill.  It uses about four ounces (120 ml) of the fluid of your choice.  

The sound it makes is different than that of an EM - maybe more “mechanical”.  It is not loud and Mike felt he could still hear what the rear tire was doing on hard surfaces. 

One of Mike's concerns was the rear master cylinder being vulnerable in a crash.  Mecatecno is aware of this and says it's more rugged than it appears and can withstand a lot of abuse.   

Parts are not expensive.  The bike has already needed a replacement rear fender for $60.

There is a 2-year warranty on the bike, but only 6 months on the battery.

Note that Mecatecno's battery capacity claim is roughly 15% greater than the battery manufacturer's rating.  This is because Mecatecno uses the battery's maximum voltage whereas the battery manufacturer uses a more depleted value.

Bottom line: the test did not reveal anything that would stop Mike from buying one.  On the other hand, it was not so fantastic that he planned to place an order immediately.  Mike would like to test the bike at one of his riding spots.  That would settle the buy or not buy question.  But that's months off given the weather.  Mike would probably keep his EM even if he gets a Dragonfly.

Miscellaneous Observations

There is no conventional 17-character VIN (vehicle identification number) on the headstock.   Each bike is uniquely identified by markings near the countershaft sprocket.

The 2023 Dragonfly weighed 137 pounds on a hanging scale.  On the same scale, a 2022 EM Race weighed 170 pounds.  Note that the Dragonfly scaled 6 pounds lighter than I was told by a different source using an identical procedure.

There is no DC-DC converter.  Power for the LED headlight comes directly from the controller (via a 10-volt output rated at 50mA). 

The Dragonfly uses a standard motorcycle lanyard kill switch.  The switch closes when the magnet is missing.  This provides the opposite action of the special and more expensive unit used by EM.

A Leonelli control on the left handlebar contains the “start” button, the map-select button, and the map indicator LED.  

The controller powers up in Green mode when the start button is pressed momentarily.  There is no neutral.  White mode (less powerful than Green mode) comes after Red mode in the map sequence.  Some of the early bikes were programmed for a  White-Green-Blue-Red sequence.  Mecatecno does customer surveys, and 50% said they had no use for White mode, so maybe that's why they stuck it at the end of the sequence.  Although, I have been told it's great for getting out of a muddy stream.

There is a small guard for the rear disc.  The front disc has a typical guard. 

Although the footpegs are nice, the brackets look pretty poor.  This may explain why Mecatecno is offering the red adjustable ones for an additional $223 USD.

Venting

In addition to the vent near the countershaft sprocket, there is a vent directly into the motor casing.  Both vent lines terminate near the heatsink for the controller.