Please review this before I place an order

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AF7JA   100 W

100 W
Posts: 132
Joined: Jun 09 2015 3:56pm
Location: Salt Lake, UT

Please review this before I place an order

Post by AF7JA » Feb 09 2020 2:10pm

This is going to go an a Rotovello (a moderately heavy velomobile). I also have a 48V 30AH LiFePO4 battery that I will be using with it. My goal is not high speed, instead, I am looking for range and the ability to pull a trailer with solar panels. I already have the solar panels and charge controller from my Kansas to Utah "never plug in" tour.

So this is basically the IGH hub motor from

Motor Winding Type ( Fast 395 winding recommended for 20" wheels) 1 x IGH_395

Include a Wheel Build?1 x WheelBuildSelect Rim for Custom Wheel Build

1 x Rim20_AlexSelect

Spokes for Custom Wheel Build36 x Sapim Strong 13-14g Butted Spoke, Black

Controller1 x C4825-GR

*Cycle Analyst or LED Display Console?*1 x CA3-DP

Throttle Choice1 x T-Lever

include *Tidy Wiring Kit?*1 x WireRouteKit

Nightdiver13   1 mW

1 mW
Posts: 10
Joined: Mar 19 2019 9:20pm

Re: Please review this before I place an order

Post by Nightdiver13 » Feb 09 2020 2:53pm

Have you run that motor configuration through Grin's trip simulator on the more stressful (hills, temp, etc) parts of the trip you're planning? My experience with running that hub through the simulators is that it heats up pretty quickly with the combo of gradient (length and/or severity) and higher gross vehicle weights.

AF7JA   100 W

100 W
Posts: 132
Joined: Jun 09 2015 3:56pm
Location: Salt Lake, UT

Re: Please review this before I place an order

Post by AF7JA » Feb 11 2020 8:51am

Just to follow up, I got come information straight from Grin.
  • Even though the website says to use the faster winding for 20" wheels, they suggested that I go with the slower winding
  • As expected, the CA 3 will give me more of what I need, including built-in (as compared to modifying the CA right out of the box) temperature monitoring.
I will probably add the Stator Aide; In the simulator, it seems to do some good. I will probably add the brake levers, I have some, from another kit, lying about but they were os such poor quality that I never used them, I hope Grin's are better. The thinking of the brake levers is that, when touring, the total rig will probably be heavy enough to get some value from regenerative braking.

As far as grades go, on the Kansas-Utah my steepest grade was about three miles of 13% (I broke a few chains on that one, then rode back to Pueblo to get BMX chain. I can safely say that hill took three days to climb). Then there was a long grade of about 7%. I had to stop on that one and let the solar panels do their stuff while I read and went for a short hike.

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dogman dan   100 GW

100 GW
Posts: 35305
Joined: May 17 2008 12:53pm
Location: Las Cruces New Mexico USA

Re: Please review this before I place an order

Post by dogman dan » Feb 14 2020 9:21am

Mid drive it would be better. especially if the weight gets really big.

Not that you can't do a heavy rig up hills with a hub. But a strong mid drive will be better.

DO NOT pick the fast wind for a trailer hauling hub motor. You want the slower wind. Because all that weight will have you going slower, unless you choose a really big motor that can handle 2000-3000w, which is what it takes to go 15 mph up a mountain pass weighing over 400 pounds total weight.

So if your motor is going to push you up that hill at 10 mph, pick a motor that runs efficiently that slow, under heavy load.

So you need the 305 motor for sure. I can say for sure in 20" hub 400 pound load outs will be fine. It will have about the same capabilities my low power trailer hauler had. Over 400 pounds loads, that will need a mid drive, or larger more powerful motor.

My rig had 48-52v, 22 amps, 20 inch wheel and 500w rated, lower speed dd motor. It hauled me, 2000wh of battery, and a bob trailer with 30 pounds on it up my motor melting test mountain easily without overheat. 400 pound load total. So you will get that at least with a 305 rpm motor. Exact same load with higher rpm motor did make it too, but very hot at the top of the 5 mile long climb. It was pushing it to the very limit with the faster wind, and a watt limit less that 2000w.

Weigh it all, if its over 400 pounds, you need to mid drive it, or two hubmotors so you have 2000w + when it gets steep and long.

Taswegian   100 mW

100 mW
Posts: 39
Joined: Dec 17 2018 8:21am

Re: Please review this before I place an order

Post by Taswegian » Feb 15 2020 7:47pm

Is a derailleur an option? The sim suggests that in this power class a GMAC can be far stronger than a TCDM at low speed if fed enough current whilst retaining regen.

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