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Help with GMAC superharness rear hub order


1 mW
Mar 22, 2023
In another thread, the experts here convinced me to go with a rear hub motor instead of a BBSHD mid drive on my HP Gekko comfort trike. After reading the GRIN website and a few emails with Hayley there, I have decided on ordering a GMAC Super H kit.

GMAC SuperH Kit

I chose this kit because I do not like the V3 Cycle Analyst display, it looks too complicated for me and since the display is where most of the wires go it seems ill suited for a trike with very little horiizontal real estate. I like the 600 display available with super h kit better.

So this is my order, I just have a few questions about cable extensions needed and a few other things. I ran this kit on the simulator and it looks like it will work just fine for my needs (total weight me, bike and dog 300lbs, mostly flat Florida riding, 25 mph)

GMAC super H kit rear: GMAC SuperH Kit

GMAC 10t wind
Cassette: None, using Sram cassette on the trike
Disk rotor: None
Rim for geared hub: 26 DM 30
Spokes: Sapim strong silver
GRIN wheelbuild: Yes
Controller: V6 L10 baserunner
Controller Mount: None, I think it fits inside my Hailong Shark battery S039-3 48V 13ah, see photo attached
Display Model: 600 integrated
Display harness: Main 9
Throttle: Thumb throttle with clamp, 40 cm Higo 3 pin
Ebrake: None see questions below
Pedal Sensor: 24 pole PAS (see question below)

Any comments or suggestions most appreciated, be advised I know nothing about bike mechanis, electric motors and cables etc, just trying to order complete kit so my mechanic can install.

Ok,Questions I have

1. Am I correct that controller will mount inside my hailong battery?

2. My Gekko comfort has a single brake caliper with dual activator cables on the right handlebar, this really simplifies braking do not want to lose it. The superharness ket only comes with Ebrake levers digital, Hayley at Grin said I could use the Ebrake push pull tripwires if some soldering was done. I have no idea how to do this perhaps I can order an ebrake sensor like bafang makes that needs no modification? Pull Tripwire (50cm Cable)

3. Pedal sensor, I think my trike has the space by the crank to use the 24 pole PAS, have to go check at the shop.

4. extension cables needed.to connect everything. Baserunner - Grin Products - Product Info

Attached is a schematic I drew of the GMAC super H kit with distances between components. I need to figure out what cable extensions my mechanic will need to install the system on a trike.

Controller to battery, think I have enough length already, just need a couple andersson connectors to attach

motor cable to controller is 38 cm long, this should reach as battery/controller are right next to rear wheel

6 pin PAS sensor, distance from crank to controller = 150 cm

( pin mains cable The V4 Baserunners also feature a 9 pin waterproof plug that brings out the cables commonly used in ebike wiring topologies with a main signal harness that splits out at the handlebar into throttle, ebrake, 3rd party display, and light connectors. 600 display and throttle will mount on left handlebar, ebrake sensor will mount on right handlebar (where single brake caliper - dual activaator is mounted. Distance from left or righ handlebars is 100 cm.

I am sure all this is remedial to you guys but my hair catches on fire when I try to figure it out. Would appreciate it greatly if you could answer my questions above and also provide links to the exact cables I need to make this kit work on my trike. Just trying to make it easy for my mechanic.


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GRIN wheelbuild: Yes

For the wheel build ask ebikes.ca to use "spoke elbows in" on the non drive side and "spoke elbows out" on the drive side. This allows the wheel to be dish-less accordingly to ebikes.ca's own spoke calculator. Dish-less (which is only possible on five* rear hub motors that I know of) allows all the spokes to have the same tension as well as the same length.

*Four of which (two are 7 speed freewheel and two are single speed freewheel) are not sold by ebikes.ca which makes the GMAC the only cassette hub and the only rear hub sold at ebikes.ca capable of being dish-less.

P.S. I am assuming the MAC Cassette hub motor (being the foundation for the GMAC) is capable of being dish-less as well, but I haven't confirmed this yet.
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Hey I just finished (yesterday) a Grin SuperHarness build with a rear All Axle V3 motor on a longtail. I'm planning a big write up but feel free to message me with any questions. I did need a second order of the 9 pin mains cable as the stock cables didn't reach all the way to the handlebars where the Superharness goes.

As for brakes, soldering isn't too hard. I know Tektro offers some hydraulic brakes with ebrake cutoff where one lever controls two calipers.

My children are actively climbing on me now so I can't offer a better response but just shoot me a message happy to let you know how things went.


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Am I correct that controller will mount inside my hailong battery

Grin sold the properly machined metal mounting plate/heat sink for the controller. That should be part of your order, and I don't see it on their website just now. I only see Reention mounting plates and external (bike frame) mounting plates. You want one - it soaks up extra heat and connects it to the air to cool. You also want to use thermal compound (I use Arctic Silver or other computer CPU heat paste) on each of the 5 or 6 little screws that hold the controller to this metal mounting plate.

Your battery may already have this in place in the cradle - check there, although I can't tell whether it's machined to fit the Baserunner.

Another issue - soldering the wires from the Baserunner to the connector in the battery cradle that the battery plugs into is not easy. When I tried it at home, my soldering iron wasn't hot enough to raise the temperature of the metal pins before making the plastic holding them melt. My fabricator has a serious soldering iron and he dialed the temperature right up to accomplish this.

If you buy the battery from Grin, they solder the connector to the Baserunner pigtails and would at least mention the mount if they didn't have the metal plate. An alternative is to get them to solder the battery connector to Andersons and also solder Andersons to the Baserunner to make the connection - but that doesn't mount the Baserunner in the battery cradle.

I don't happen to know - does the SRAM cassette fit onto the Shimano standard freehub on the motor?
I'm looking at your schematic now and I see you don't have the superharness anywhere. On a conventional bike it goes by your handlebars. The front light, rear light, brake cutoff, throttle, and phaserunner/baserunner all connect straight to the superharness. The battery mount is integrated with the baserunner and connects directly to the PAS/torque sensor, motor, and superharness.

Depending on where the battery/baserunner mounts relative to the motor and superharness you will probably need a 9 pin cusmade mains extension cable or the battery/motor extension cable (can't remember what that's called).
[These comments are from someone with GMAC 8T + Superharness + 52V 14ah + foldable Bike Friday with [just two] 20" wheels]

>I chose [Superharness] because I do not like the V3 Cycle Analyst display, it looks too complicated for me
Agreed, CA3 is fat and ugly as sin, and with all those non-waterproof connectors. But it sure is educational!

>GMAC 10t wind
Good choice. My GMAC 8T with 52V battery will get up to 35 MPH on full throttle even with its 20" wheels, which is scary fast. 10T and 48V would be lots safer.

>Controller: V6 L10 baserunner
Yes, V6 is required for Superharness

>Controller Mount: ... fits inside my Hailong Shark battery S039-3 48V 13ah,
Right, but 13ah sounds a bit low for a trike. The regen braking is seriously constrained by how many amps you can push back into the battery. When the battery is fully charged the controller will seriously limit the regen current. So for regen braking right from the start, get a larger battery (20ah?) and usually fill it only 80% or so!

>Display Model: 600 integrated
I've tried the 750C with the Superharness, and it did work, but is rather lame. I currently use the miniature SW102, which is pathetic, imprecise, hard to read, but discrete and light weight. I sure wish GRIN would write a decent manual for these mainstream displays.

>Display harness: Main 9
The Superharness is indeed a truly elegant solution.

>Ebrake: Gekko Comfort has a single brake [lever] with dual activator cables on the right handlebar, this really simplifies braking -- do not want to lose it.
RIGHT! I'd suggest you leave Gekko's two front brakes exactly as they are: NON-electric.

Your photo shows you DO have a linear pull [rim] brake on the rear wheel, so you presumably also have a second brake lever, on the left handlebar. So... throw away this second lever plus its cable and calipers, then install _one_ of GRIN's analog proportional e-brake levers "E-EbrakeA_HG4_R_LS" or "EbrakeA_HG4_L_LS" _without_ any standard brake cable+housing. Hook it into the Superharness blue HiGo plug. Don't use just a simple ebrake lever.

[Full disclosure: ebrake levers do have a return spring but are not really designed to work without a standard activator cable+housing in there -- the empty socket for the cable barrel can jam the lever in the "ON" position. So you need to put a drop of adhesive inside the lever to keep the empty socket pointing straight out.]

So now you have Lever#1 running the two front disc brakes only, and Lever#2 running the regen ebraking [on the rear wheel] only. Works like a charm.

> 4. extension cables needed.to connect everything.
OK, you WILL surely need to set the parameters in your V6 baserunner. So you WILL need a Baserunner programming cable and a computer to hook it to: "Msc-TTL-USB".

> 6 pin PAS sensor, distance from crank to controller = 150 cm
Yes, and be sure to get a PAS sensor with the HiGo connector, e.g. "CAP-PAS_12P_HG"!