Looking for reliable 1000w rear hub motor for regen purposes

[Potato011]

I currently have a mongoose envoy equipped with a bbshd and 52v battery. This bike is my daily driver and is often loaded up to 300 lbs (rider + cargo). The areas I ride in have many long hills so I want a rear hub motor for regen so I stop shredding my brakes. I'm looking for a decently reliable 26" rear hub motor that is to be primarily used for regen but can also serve as a backup should the mid drive fail. The motor will be paired with a vesc since I want to experiment into virtual freewheeling. This bike goes offroad pretty often so ideally something with thicker spokes and rims. So far, the prime contenders are the GMAC and one of the ebikling options. I want some feedback on these choices and if there's any other issues with this idea. Thanks

heres a few pics of the bike.

 

[fooferdoggie]

a dd motor will suck on those hills. but decent brakes will cost far less. we have Shimano 4 piston deore and xt they stop out 450# tandem with 1 finger on 20% grades.

 

[Potato011]

a dd motor will suck on those hills. but decent brakes will cost far less. we have Shimano 4 piston deore and xt they stop out 450# tandem with 1 finger on 20% grades.

I'm using magura mt5s on both the front and back wheels. both wheels use 203mm rotors. I can definitely slow down and stop but not at a fast enough rate. The regen is also partially just a science project I want to try out.

 

[Potato011]

find a nice dd 1500 watt with a compatible controller,you are going to add weight.

do you have any recommendations on brand?

 

[fooferdoggie]

I'm using magura mt5s on both the front and back wheels. both wheels use 203mm rotors. I can definitely slow down and stop but not at a fast enough rate. The regen is also partially just a science project I want to try out.

with good metallic pads you should be able to lock bot wheels just fine. can't get more braking then that. we get about 2000 miles on pads and we do a lot of down hills.

 

[Potato011]

with good metallic pads you should be able to lock bot wheels just fine. can't get more braking then that. we get about 2000 miles on pads and we do a lot of down hills.

probably a good idea. i'm using organics because of noise reasons. still want to try the hub just to see how it goes

 

[charlieboom-boom]

I am using a 8T winding GMAC geared rear hub motor with a 52v24ah and a 52v28.8ah battery that I installed in a TriSled RV-2 velomobile. It had been programed with with the electronic virtual freewheeling. The effect of the REGEN braking is amazing. Even when coasting down hill at 55+mph. it will still bring me down to almost a full stop without even using the disc brakes that are on the front 2 wheels of the tadpole type configuration. I have over 3,100 miles on it so far and seldom use the disc brakes. I installed the motor cuttoff/REGEN switch on the left brake lever and adjusted the pads on the right wheel to contact the disc with very little movement of the brake lever. I only use the disc brakes when I am almost stopped at a sign or light. So seldom do I use the disc brakes that a couple of days ago I heard sort of a grating sound from the left rotor. There must have gotten some rust or dirt on the rotor. I have not had to make any adjustments after 3,100 miles to the brakes. I did have to make several adjustments to the V3 ca display controller for the circumferance of the particular tire on the 406mm rims. There can be over 100mm difference between 32-406 and 60-406 tires. I would mention that it is a good idea to check and tighten up all clamps and parts of the torque arm. They can get loose over time If the torque arm comes loose and falls apart it will cut the motors power cord The REGEN in the 8TGMAC motor is developing up to 1.2kw of braking power. And while I electronicaly turned down the motor to 1,800 watts from 2,000watts peak output. At full throttle on flat level ground and no wind the controller display indicates that the watts being used falls off to 350-375 being used. That is all the power need to maintain the top speed to overcome the wind drag and tires rolling resistance. The REGEN braking will really reduce the brake pad wear. The RV-2 velomobile with the 2 52v batteries, tool kits and other stuff at a bit over 120 lbs.. The first tadpole e-trike wore out the disc pads at 2,400 miles before replacing them was necessary. The top speed was 10mph slower than the velo. One thing that supprised me when I went over the full throttle top speed on a steep downhill that it began some REGEN. Just a few watts and the amount of watts increased as the speed increases. I would definately reccommend going with Grin's GMAC series motors for REGEN braking.

 

[charlieboom-boom]

I can you about the srounging around and trying to go the "cheap" route. Sometimes it gets turned around and ends up biting you in the ass. I bought a 11 year old Sun EZ3 HD delta type semi-recumbent trike on a consignment sale from a LBS. I e-mailed Sun to find out the date it was made. It was literley in brand new condition. No wear on the cloth padded seat, no grime or rust on the chain or gears, and the Maxix Hookworm 53-406 tires still had all the mold marks and nubs of rubber that new tires have. The price was $890.00 So I thought great. I knew that I could buy a conversion kit for $650 (4 years ago) without a battery. (I used the 48v20ah battery from my first e-trike. I could get a front wheel kit from E-Bike Kit and it would be the same as The Sun EZ3 trike that thier sister company (ElectricTrike) sold for $2750 at the time. It was and worked good except there was no traction on the front wheel because of no wieght being on it. Even after putting 40-406 Winter studded snow tire on the front motored wheel the 500watt still would spin. Next step was a 750 watt Bafang Mid drive ($600) to power the right rear wheel, Winter studded 55-406 and a Schwalbe Pickup 55-406 on the left so the tire psi would be the same for both rear wheels. Another $500 for a 52v28.8ah battery to power the 2nd motor. And probably around $700 total to remove the under the seat steering, build a front head tube steering system with "Ape" type handlebars to mount all the throttles controls and the displays for both motors. A new indexed 7-speed shifter. (I did not like the twist shifter and the cable was to short to be used with the ape bars.) Running 3100mm long brake cables and tubes to the 2 rear disc brakes. I just checked Electric Trike is selling the Sun EZ3 right now for $3,514.00 plus shipping. So I probably "saved" a few dollars overall. And have a 3x2 driven e-trike that can really go in the snow and ice. And it has 90 plus miles of range if I don't use both motors at the same time.. You are right that "GrinTech" is first class. The 8TGMAC was the only choice to put into the RV-2 velo. The prices for velomobiles are crazy. The base price is $9,000.00 AUD ($6120.00 USD) plus extra options. I went with the RV-2 because the roto-molded fairing is much more durable than the fiberglass or carbon fiber on the velo's from europe. I've tipped mine twice and you can hardly see the scratches. The total cost including shipping costs and customs brokerage and duties and motor kit from Grin was about the same as the velo's from Europe without customs, shipping. and motor. About the only extra customisation I am thinking to do is to send the boom's bottom bracket to Utah Trike to machine and install a 34T Schlumpf High Speed Drive. The 2.5 to 1 drive would make the 34T chain ring equal to a 85T. That would let me pedal on flat ground faster than the e-motor. I think that 35-40 mph would be possable. And the 34T would give me a much lower gear ratio for starting up than the 58T front chainring does now.

 

[Slaphappygamer]

I made a similar “mistake” as mentioned above. I first changed out my controller and display to a KT system. Grins CA and BaseRunner were too expensive. I used the KT system for almost 2 years and it was great. I finally did enough research to be more confident that I could install a CA and BaseRunner. I have that now and wish I would’ve moved right to it, instead of getting the KT system. Seems like I wasted money since I just went to Grins system anyway, but I did learn a lot.

Save extra money and get what is best for your bike, not what’s best for your wallet.

I would go with the GMAC motor. Perhaps, have you looked at using that motor in the front so you can have both wheels driven at the same time? That would help on take off with a heavy load.

 

[charlieboom-boom]

The 8TGMAC motor has proven to really be the perfect choice for the RV-2 velomobile. The 1.2kw of REGEN braking it can provide is very effective at bring it to almost a complete stop while on a down hill coast at 60mph. without even using the 2 disc brakes on the front 2 wheels. (and a 120 load on a trailer behind it.) I know that the REGEN works and it has eliminated my worry about brake steering at high speeds. One feature that I did not know about (actually 2) of the REGEN braking is that it can be set in the V3 CA display to act as a sort of govenor to not allow the down hill coasting speed to exceed what ever speed I choose to set it at. (set at 60 mph.) And when the coasting speed goes over the maximum rpm for the voltage rpm of the battery powering the motor. The 8T winding of the GMAC provides 10.2 rpm per the batteries voltage. (compared to 8.2 rpm/volt of the 10T winding). With a 52v24ah battery fully charged to 58.8v the top speed is about 30.5mph. When that speed is reached on a down grade and begins to coast down faster the motor begins generating a little power which is just 1 watt and slowly increases the wattage as the speed increases from going down the hill. When the top speed gets to the 60mph setting that I set the governing feature at it automatically uses whatever amount of REGEN braking is needed to prevent going over the 60mph limit. 3,175 miles and no adjustment to the disc brakes yet. Though I will need to adjust the left one a little due to cable stretch from using the locking parking brake feature that all trikes seem to have. E-trikes being so very heavy tend to wear out the disc brakes pretty fast. Both the tadpole and delta trikes have had the pads replaced at aroung 2,400 miles. But with REGEN in the RV-2 velo, I'm starting to believe Justin's claim that it might be 30,000 miles before needing to replace the pads.

The 3x2 dual motor does real good at pulling a trailer loaded to 120+lbs. Using the 14T-28T 7speed rear gear cluster gives a lot of pulling power from the 750w BaFang mid drive motor. The front hub motor with the studded snow tire is only really needed to help with steering control on snow and ice. Both the delta and tadpole trikes as well as the RV-2 velo are set up to pull the trailer. The 500w rear geared hub motor in the tadpole trike is a little weak when it comes to pulling a heavely loaded trailer.