Front Direct drive Fatbike motor (135mm)

Jordan

10 µW
Joined
Jun 1, 2012
Messages
6
Location
Canada
I’m looking for a 500-1000w direct drive front hub motor with 135mm spacing for a 20” Fatbike.

Just wondering what my options are, can only find generic motors ~1000w with a big flange diameter and prebuilt wheels with radial lacing.

Thank you
 
Tell us all the places you have looked to find hub motors/laced hub motors?
Before we start repeating the places you've already looked.
You are right, 20" rim will require radial 0x lacing.



Jordan said:
I’m looking for a 500-1000w direct drive front hub motor with 135mm spacing for a 20” Fatbike.

Just wondering what my options are, can only find generic motors ~1000w with a big flange diameter and prebuilt wheels with radial lacing.

Thank you
 
Checked ebikes.ca, ebikeling, crystallite, golden, leaf, amazon, aliexpress, ebay etc. lots of googling; Most things I have found look like this:
s-l1600.jpg

with a big flange diameter and narrow flange spacing. Can't find any smaller fat direct drive motors.

Looking for something I could lace 1x at least. Its for a 2wd cargo bike so it will be supplementing a rear motor mainly for traction and for Regen. Don't want to go too big and stress the dropouts and id like to avoid radial lacing.

Where else should I look for hub motors? Would like to use a grin all axle motor but there's no adapters for a 135mm hub.
 
Luna Cycle dont do hubs no more
Then there is Leafbike AND Leafmotor
Which companies on Aliexpress did you look at? There are some good companies.
On Aliexpress there is EVfitting Greentime sells hubs
also on Aliexpress the official MXUS website the name doesnt come to me off hand but I would recognize the name.
Then mxus also has a normal website and alibaba website which can be hard to navigate because they repeat the same motors to snag 250w scared uk/aus sales, 500w sales elsewhere and 750w elsewhere as well, then all the high powered stuff 3kw (135mm dropouts with 5/6/7spd) and 5kw (155mm dropouts)

Jordan said:
Checked ebikes.ca, ebikeling, crystallite, golden, leaf, amazon, aliexpress, ebay etc. lots of googling; Most things I have found look like this:
s-l1600.jpg

with a big flange diameter and narrow flange spacing. Can't find any smaller fat direct drive motors.

Looking for something I could lace 1x at least. Its for a 2wd cargo bike so it will be supplementing a rear motor mainly for traction and for Regen. Don't want to go too big and stress the dropouts and id like to avoid radial lacing.

Where else should I look for hub motors? Would like to use a grin all axle motor but there's no adapters for a 135mm hub.
 
Jordan said:
<snip>
big flange diameter and narrow flange spacing. Can't find any smaller fat direct drive motors.
That's unfortunately pretty much the definition of ebike DD hubmotors at present, fat or not, from all the ones I've seen.


Looking for something I could lace 1x at least. Its for a 2wd cargo bike so it will be supplementing a rear motor mainly for traction and for Regen. Don't want to go too big and stress the dropouts and id like to avoid radial lacing.
I know of no direct drive motors small enough to do anything other than radial lacing in a 20" wheel. Geared hubmotors, but not DD. The smallest diameter (by just a little bit vs typical ones) DD hubmotor I've personally had is the Ultramotor, which was used on some Stromer bikes, and A2B Metro, etc. Don't know that it's available anywhere except used off one of these bikes; they are nice motors though. However, still probably too big for anything other than radial lacing--it *might* be possible to do 1x...but it would likely be a PITA to do.
https://endless-sphere.com/forums/viewtopic.php?f=2&t=67833&start=1025#p1711799
file.php


There *are* some scooter hubmotors that might be small enough, but all the ones I've seen come with rims built onto them, not spoke flanges, so for those you'd have to machine something to replace the rim with. (which might require machining a new rotor and installing new magnets on it, depending on it's design and on how small a flange diameter you need).

THere are some with wider flanges, but they are also much heavier; QS205, MXUS 450x, etc. This image shows an MXUS 450x on the trike, and the not-yet-mounted Ultramotor off an A2B Metro (still in the complete Metro wheel) in a blue bike frame to do some testing using the SBC's controller/etc. It's hard to tell exactly how much different they are, but you can see that the spokes are longer on the Ultramotor wheel than the MXUS wheel, though both are 20" rims.
file.php




The ones I've seen are rear motors, but there's nothing stopping you from using them on the front--just don't install the freewheel cluster on them, since you don't need it (I did this with an ex-stromer ultramotor in a 26" wheel on a fatbike fork on SB Cruiser for a while, but the fork was very poorly made and began to fold up from braking forces, so the experiment was ended before I got any motor testing in--worked fine as a wheel, though). But they are all still the same large diameter, and still need radial lacing in the 20" wheel.
https://endless-sphere.com/forums/viewtopic.php?t=86600#p1466764
file.php

file.php


Would like to use a grin all axle motor but there's no adapters for a 135mm hub.
You can ask them if they can make one. The nice thing about that hub is that it is possible to make an axle adapter to work with quite a lot of setups. ;)

Note that AFAICT the GAA DD hubmotor is also going to need radial lacing in a 20" wheel, but it's probably listed in the Grin spoke calculator so you could "build" it into one there to verify if it might work or not. .



FWIW, the radial lacing, if done with the right (thin!) spokes for the rim used, can still be plenty strong. Using radial-laced wheels I built onto the various motors I've tested (primarily the MXUS 450x's for the last long while until I started using the Ultramotors on the right side to replace a failed MXUS), I carry up to hundreds of pounds of cargo (groceries, dog food, dog, etc) in the back of the itself-very-heavy SB Cruiser, and have broken rims on potholes without breaking spokes, and even axles. I *have* had a couple of broken spokes on the left wheel (which is odd because most of the damage happens on the right due to being on the worst part of the edge of the road), but it's very rare.
 
Since it will be a dual motor setup, why not get your regen off the back wheel, and use any 135 mm axle spacing rear geared motor for your front hub. Then you can lace it 2x.

For a rear 20" motor, you would be able to do the same thing, if you can live without the regen. Coasting geared motors can be almost as good as regen, especially if the downhill grade is not steep.

2x geared motors will power a cargo bike just fine, feed each one 52v 20-25 amps.

If your rear wheel is 26", then easy to put a dd in there with 2x lace.
 
Thanks for the replies, I appreciate the suggestions.
I was looking at using a rear 135 with wider flange spacing but would rather avoid a weird dish. Trying to avoid radial but l thought the grin motor with paired spokes would be better than straight radial, asked about adapters but nothing available; might try and cobble something up later but just going with a generic front dd like i posted for now.
It’s a longtail cargo bike with 20” wheels front and back, I want the dd in front where it’s less loaded, I also already have a geared hub and a bbshd for rear motor options.
 
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