Mecatecno Dragonfly

Introduction

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

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.

The information presented here is a combination of public data, observations, and reverse-engineering.  Some of the information I have found is inconsistent/contradictory.  As I learn more, I expect to reconcile the differences.

As of October 2024, there is a Dragonfly in our garage.  It's my wife's bike and she chose it almost entirely on the basis of weight.  There is an immense amount to learn, and I will be sharing it here in the coming weeks and months.

My initial impression is that it's extremely easy to work on this bike.  Everything is very accessible.  It all seems to have been designed as a system rather than as a collection of parts. 

Original Dragonfly Prototype in USA in 2018

The adjacent video shows the original 5-speed prototype with the CNC machined swingarm.  The chassis is all tubular steel.

Probably M4 air-spring forks.  The shock spring is yellow, so probably Ohlins.

Appears to have a different motor than the production version.

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.

Dragonfly Assembly Video

Mecatechno produced an excellent assembly video for their special dream bikewhich 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.  For comparison, the standard 2024 dragonfly has a US price of $11,299.

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.

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.

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.  My wife's Dragonfly weighed in at 62.9 kg (138.5 pounds) including the sidestand and mounting screws which total 442g.

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. 

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 overor 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 three to four ounces (nominally 100 ml, I'm guessing) 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 (without stickers).

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.

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.

Subframe

I'm not sure what to make of the subframe.  It certainly is unconventional.

My first impression is that it's not very robust.  It appears to be lightweight.  Probably repairable after a crash.

Apparently, this is the improved (strengthened) version of the subframe.

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.

Fastener Torque Table

Mecatecno provided the following guidance for fastener torque.  I converted Nm to lb-ft for the metric impaired.  Curiously, there's no spec for the rear axle.