Sur Ron X Controller Review 8-17-18

This will be an ongoing post for the X Controller. I was completely intrigued by the Luna Cycle X Controller, especially after Matt Richard’s video review of the unit. I respect Matt and his reviews so I ordered one right away. Apparently Luna had only 50 of the controllers. Sur Ron is hesitant to import more to the USA for reasons unknown to me. At the time of this post they are currently sold out of the units and don’t have an ETA or when or if they will return.

Matt also created an installation video of the X Controller which is excellent. I did not follow his instructions to flip the bike upside down, but instead decided to leave the bike upright on a rear tire stand. I just felt it was a better solution for me.

One of the steps I feel is ABSOLUTELY NECESSARY whether or not you keep your bike upright or on its back is to remove the battery. You will be disconnecting the main wiring of the controller and motor so you certainly do NOT want anything to arc or short out.
Almost all of the terminal connections on the X are the same as on the stock controller with the exception of one of the connectors. On the stock controller the smallest connector is not connected to anything and contains a blank socket. On the X controller there is a small triangular shaped connector that will not be connected to anything. I surmise that it may be for a future upgrade from Sur Ron. I simply placed electrical tape over the socket to try to prevent any moisture/debris from entering.

The Red, Green, Yellow, Positive and Negative terminal are clearly marked on the X Controller.

X is on the right, the stock controller is on the left

The X controller with the small triangular plug which does not connect to anything

The stock controller’s small non connected plug with a blank inserted.

I taped over the X controller’s triangular plug.

All buttoned up and ready for the test ride.

Performance

Luna makes the following claims for the new X Controller

  • 25% increased power from the stock controller
  • 10% increase in top speed
  • Smoother, more linear power band
  • Regenerative braking.
  • ($220 trade in for old sur ron controller)
  • Plug and play installation (max 20minutes)

So let’s take these one at a time….

25% increased power from the stock controller – TRUE

Because I have no ability to test the increase in power on a dyno (nor do I think anyone has as of this writing) I cannot say objectively that the increase is specifically 25%. What I can say and attest to is my seat of the pants experience. Prior to the X I had installed the 60t Luna sprocket. Prior to its installation, I was happy, but not thrilled with the torque of the Sur Ron. It was good, but I wanted more grunt down low for the type of riding I enjoy. Installing the 60t over the stock 48t provided me with the amount of low end grunt I wanted. Sure I lost about 15 MPH of top end, but my riding is primarily in the dirt on climbs and so losing the top end didn’t bother me much. Instead of the claimed 45 MPH I could only attain 42 MPH according to the Sur Ron display. LOL, as if 42 MPH on a 110 pound bike is slow, yeah right.

I had the 60t sprocket installed on my bike when the X arrived. After installation I took it for a test spin. Holy Shit! The increase in power of the X combined with the 60t sprocket was too much for my taste. Now some will ask “How can too much power be a bad thing?” I’m all about control of power, not brute power. So I switched back to the 48t and thought “OMG this is the PERFECT combination for me, the torque of the 60t with the top end of the stock sprocket.” So my seat of the pants assessment, absolutely it has a 25% increase. Maybe more like a 30% seat of the pants increase.

10% increase in top speed – TRUE

I have the pedal kit installed so I feel that the extra drag created by that kit reduces the actual top speed compared to a non-pedal kit bike. Before installing the X I could attain 42 MPH. With the X I could achieve 47 MPH. That’s a 12% increase. I have started to use a phone app that tracks speed using GPS positioning. At the time I saw 47 MPH on the Sur Ron’s display my GPS app showed 43 MPH. So the Sur Ron’s may be off a bit, but that does not mean the top speed didn’t increase with the X.

Smoother, more linear power band – TRUE

For me this may be the best part of the X. Prior to it, whenever I started increasing the throttle the bike would slightly ‘lurch’ forward. Not dangerously so, but it would not be smooth. And I have always prided myself on great throttle control skills based on my race training. With the X controller, taking off from a dead stop is now like a fine car….smooth as silk. And the power curve? Again, no dyno, but seat of the pants assessment is it is linear all the way up to about 80% of maximum throttle. That is where the power levels off. It does not shut down completely; it’s just not ‘pulling’ strongly at that point. The stock controller has a big initial jump, then levels off at about 30% throttle, and levels off again toward 75%. It becomes completely flat after that.

Why is smooth linear power so important to me? Well I ride single-track and places where there is loose gravel or dirt on top of hard pack. And when there is pavement it is often covered with silt or dirt. Getting on the pipe when on surfaces like this can lead to the rear end sliding, overshooting a turn, a myriad of unexpected stuff if throttle input is not smooth. Imagine having an early generation turbo engine or a two stroke bike. There is a flat spot and then all of a sudden the power comes on. This is an exaggeration of the stock Sur Ron, but it helps illustrate the difference between stock and the X. Throttle input is strong, smooth and predictable with the X. Much more so than with the stock controller.

In some ways I feel that presents a safer situation than the stock controller, ESPECIALLY the stock controller paired with the 60t sprocket. Because the power delivery is much more abrupt with the stock one, the torque hit of the 60t can be surprising. This is NOT to say the stocker is dangerous, just less predictable than the X. Enough said.

Regenerative braking – TRUE

I’m going to combine regenerative braking and engine braking here which is something Luna does not mention. In terms of engine braking for those who have not ridden a regular 4 stroke motorcycle, imagine you’re driving your car. You are approaching a stop light and remove your foot from the accelerator. At that very instant you shift your automatic transmission to “N” for Neutral. What you would feel is the car NOT slowing down, but coasting fast, much faster than you want. THAT is how the stock Sur Ron feels with the normal controller, no engine braking. Basically the compression of gasoline powered cylinders doesn’t slow you down, which is the nature of electric motors. NOW with the X – that feeling, that physical action of engine braking HAPPENS.

What it creates is a more ‘natural’ feeling, one most of us associate when we lift/turn our throttles off, not coasting, but SLOWING. The X accomplishes that in spades. On downhill sections, approaching a stop; letting off the throttle SLOWS YOU DOWN without the need to apply the brakes.

Doing so then regenerates the battery pack. I did not measure the voltage (like Matt demonstrates in his great video) during my tests. BUT what was apparent is on the very same 17.4 mile loop going approximately the same speeds, in the same wind/topography conditions – here are my very unscientific battery readings:

Stock Controller:

  • 100% charge at start
  • 17.4 mile loop
  • 3 miles of full throttle
  • Combination of dirt/pavement riding
  • Battery reading upon returning home: 48%

X Controller:

  • 96% charge at start
  • 17.4 mile loop
  • 3 miles of full throttle
  • Combination of dirt/pavement riding
  • Battery reading upon returning home: 52%

($220 trade in for old sur ron controller) – Unknown but TRUE

I have not sent mine in, so I cannot attest to this being true. HOWEVER I have NO DOUBT that Luna honors what it says. And what for me is even more important? Honoring early adopters by offering a trade in amount….unheard of in my world! Bravo!

Plug and play installation (max 20 minutes) – Nope not for me!

So Matt’s video shows him installing the X with little to NO issues. Well…. That’s fine for him, but not for me. I had a hell of a time removing the wiring connectors from the neck of the bike. Yes I removed the tip over switch bracket, but the damn horn was in the way. And when I tried to unloosen the hex bolt to the horn bracket it was so tight I just gave up!  So I pushed the horn to one side and was finally able to work the wiring connections free from the neck of the bike. Whew! In total it took me about an hour to complete the job. And my cussing scale was 8/10, mostly at Matt for making it look so fucking easy! LOL

This is certainly not my last or only post about the X. It will be ongoing as will my experience with the Sur Ron. I do NOT want anyone to get the impression that the bike is shit without the X! Far from it. The Sur Ron is a REMARKABLE bike, an INCREDIBLE value. The X Controller takes it to a different level in terms of smoothness, power, engine braking, and regenerative charging for 270.00 with the 220.00 trade in! Insane!

Unfortunately as I write this they are sold out. And Luna has stated that they are unsure if Sur Ron will supply more of them to the US. If true that’s sad because it’s wonderful upgrade to an already incredible machine. IF they are offered again, don’t be ‘that person’ and ‘wait’ just buy one!

X Controller Update 8-18-18

So today I opted to remove my moped plate and ride as an “ebike” to visit Joe and Luis, the two fellas of Motostrano in Redwood City. Motostrano is where I purchased my Haibike Fullnine RC “Sofia” as I named her back in 2016. And yes I still ride her regularly, she’s not to be ignored…LOL. I wanted to ride to Joe’s shop in a combination of bike path/on public roads to see how the X performs in regenerative braking and charging. Unlike my prior test the Sur Ron was fully charged to 100%. When Wall-E is fully charged I always start off in EP mode. Why? Well I am aware that the X controller does not have the ability to discontinue regenerative charging during deceleration even if the battery is at 100% capacity. This ‘could‘ damage the battery, the engine or both. So I travel about 2-3 miles in EP mode to bring the charge down to 95-97% just to play it safe.

Today’s combined dirt/public road journey was 15.9 miles round trip with a top speed of 38 MPH. Both of those stats are from the Sur Ron display since I did not use the GPS app on my phone. The route I took today was relatively flat as well. At no time did I use full throttle during this ride.

One of the things I noticed about riding on the street is I tend to NOT rush toward a stop and then chop the throttle. So getting off the throttle smoothly and early resulted in me slowing down much more quickly and well before the intersections. I had to give a little throttle to reach the intersections! LOL This indicated to me just how strong the X’s engine braking affects the bike. I was riding on the stock tires as I have not yet changed to the Moto kit.

Upon returning home my battery indicated a remaining charge of 61%.

No comment yet, add your voice below!


Add a Comment

Your email address will not be published. Required fields are marked *