Help decide between All-Axle and GMAC

General Discussion about electric bicycles.
irf23   100 µW

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Help decide between All-Axle and GMAC

Post by irf23 » Jun 04 2021 5:50pm

Hey All,

I am looking to join the eBike world by building my own so I have been doing some research. I have narrowed my kit down to the motor selection, and I wanted some insight or opinions.

The things I really wanted:
- Light
- Well Built
- Easy to Install
- Low Maintenance
- Regenerative Braking
- Serves my use case well

It's the last thing that I find so subjective.
Here's what I have for my use case:
40-60 km range
up to 5km of 5-7% hills (Vancouver. BC)
Up to 32 km/h but not more
90% of the time spent on pavement

So far I have decided on a 36V 17Ah battery with a Baserunner. I am caught between the Grin All Axle and the GMAC. Would the All Axle be good enough for what I want to do? Is the GMAC just the obvious choice for me?

I have attached screenshots of the two setups. Note I added the Phaserunner instead of the Baserunner because the battery I want isn't in stock so I offset the price.

I also wanted any opinions if it's possible to have a Hybrid as an ebike or if I should stick with converting the MTB. Also attached pics.

Thanks for reading.
Attachments
AllAxle.PNG
AllAxleCart
AllAxle.PNG (47.53 KiB) Viewed 530 times
GMAC.PNG
GMAC Cart
GMAC.PNG (31.79 KiB) Viewed 530 times
IMG_20210604_153437.jpg
Hybrid
IMG_20210604_153437.jpg (2.07 MiB) Viewed 530 times
IMG_20210604_153529.jpg
MTB
IMG_20210604_153529.jpg (3.06 MiB) Viewed 530 times

JackFlorey   100 kW

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Re: Help decide between All-Axle and GMAC

Post by JackFlorey » Jun 04 2021 5:53pm

irf23 wrote:
Jun 04 2021 5:50pm
So far I have decided on a 36V 17Ah battery with a Baserunner. I am caught between the Grin All Axle and the GMAC. Would the All Axle be good enough for what I want to do? Is the GMAC just the obvious choice for me?
I think it depends on whether you want to do a rear hub or a front hub. Front hub - go with All Axle. Lighter, more efficient, and it supports the motor Justin designed*. Rear hub - GMAC.

(* - supporting this means we will see more products like this.)

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Re: Help decide between All-Axle and GMAC

Post by 99t4 » Jun 04 2021 10:11pm

irf23 wrote:
Jun 04 2021 5:50pm
I also wanted any opinions if it's possible to have a Hybrid as an ebike or if I should stick with converting the MTB.
Depends mostly on the quality of the roads in your area. Poorly maintained, numerous potholes, R/R tracks, etc. strongly favor at least front suspension and wider tires. It becomes more of a safety factor as well at higher speeds.

irf23   100 µW

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Re: Help decide between All-Axle and GMAC

Post by irf23 » Jun 05 2021 10:43am

JackFlorey wrote:
Jun 04 2021 5:53pm
I think it depends on whether you want to do a rear hub or a front hub. Front hub - go with All Axle. Lighter, more efficient, and it supports the motor Justin designed*. Rear hub - GMAC.

(* - supporting this means we will see more products like this.)
Yeah, I guess my dilemma boils down to front vs rear. I am not sure what I want. I thought I preferred the Front since it just seems easier to install and spreads the weight around. My only worry is doing 5km stretches of 7%. The reason I was thinking rear hub was because it seems to be common advice to say "If you're riding Hills = Mid-drive or Rear-Hub".


99t4 wrote:
Jun 04 2021 10:11pm
Depends mostly on the quality of the roads in your area. Poorly maintained, numerous potholes, R/R tracks, etc. strongly favor at least front suspension and wider tires. It becomes more of a safety factor as well at higher speeds.
Thanks for the insight. The roads around me tend to be well maintained, but I totally get the safety factor as well. I don't think I will be topping 32 km/h though (I say that now). All things considered, I will look to convert the MTB.

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E-HP   100 MW

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Re: Help decide between All-Axle and GMAC

Post by E-HP » Jun 05 2021 11:21am

irf23 wrote:
Jun 05 2021 10:43am
Yeah, I guess my dilemma boils down to front vs rear. I am not sure what I want. I thought I preferred the Front since it just seems easier to install and spreads the weight around. My only worry is doing 5km stretches of 7%. The reason I was thinking rear hub was because it seems to be common advice to say "If you're riding Hills = Mid-drive or Rear-Hub".
I like the option of not using the front brake when the road is slick or has a loose surface. Even with variable, you need to be careful with it in the front, like on a downhill wet curve.

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spinningmagnets   100 GW

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Re: Help decide between All-Axle and GMAC

Post by spinningmagnets » Jun 05 2021 11:41am

You haven't described the commute...

For flat land, get the all axle direct drive with statorade. For mild hills, the GMAC has more torque, but a weaker heat-shedding path, but if the simulator doesn't show it overheating, it should be fine.

For steep hills, go with a mid-drive to give the motor some gears to work with...my favorite "buy it once" option is the BBSHD.

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Re: Help decide between All-Axle and GMAC

Post by RunForTheHills » Jun 05 2021 11:58am

The GMAC is not that hard to install. It has 10mm axles, so there is no filing of the dropouts. Attaching the torque arm to the stay is done with a couple of hose clamps. You will need a cassette removal tool and a chain whip to transfer the cassette from your old wheel to the GMAC wheel or you can just pay a bike shop a few dollars to do it. That is a five minute job if you have the tools. You can get the tools for under $20.

MTA: That is assuming that your old wheel uses a cassette and not a freewheel. Otherwise, you can order the wheel with a cassette with the right number of cogs. You should also readjust the rear derailleur, which is an easy task that lots of Youtube videos will show you how.
Last edited by RunForTheHills on Jun 05 2021 12:03pm, edited 1 time in total.

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Re: Help decide between All-Axle and GMAC

Post by E-HP » Jun 05 2021 12:01pm

Looks like the GMAC 10T would meet your specs:
https://ebikes.ca/tools/simulator.html? ... &grade_b=7

Can do 7% for 17km before overheating (your spec 5km)
Can do 31.7kph, higher when fully charged (your spec 32kph)
With 36V 17Ah, will go 50km (your spec 40-60km)
Supports regen

If you would relax your spec of no more than 32kph, then I'd go for the 8T. Twice to torque at 32kph as the 10T, so will accelerate to 32kph more quickly and still meets your other specs (if you back off the throttle and ride at 32kph):
https://ebikes.ca/tools/simulator.html? ... &grade_b=7

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Re: Help decide between All-Axle and GMAC

Post by irf23 » Jun 05 2021 1:04pm

E-HP wrote:
Jun 05 2021 11:21am
I like the option of not using the front brake when the road is slick or has a loose surface. Even with variable, you need to be careful with it in the front, like on a downhill wet curve.
This is a good point that I hadn't considered. Thanks.
spinningmagnets wrote:
Jun 05 2021 11:41am
You haven't described the commute...

For flat land, get the all axle direct drive with statorade. For mild hills, the GMAC has more torque, but a weaker heat-shedding path so add statorade to both options.

For steep hills, go with a mid-drive to give the motor some gears to work with...my favorite "buy it once" option is the BBSHD.
Thanks for the response. I did put a blurb in the original post, but I can expand on that if I can.
irf23 wrote:
Jun 04 2021 5:50pm
Here's what I have for my use case:
40-60 km range
up to 5km of 5-7% hills (Vancouver. BC)
Up to 32 km/h but not more
90% of the time spent on pavement
Daily commute is 20km round trip. Around avg grade of 1.5% with very short sections from 5-10% (Vancouver is no SF). Also, I didn't think I could put Statorade into geared hub motors since the rotor shell isn't exposed to ambient air. I would love if that wasn't the case.
RunForTheHills wrote:
Jun 05 2021 11:58am
The GMAC is not that hard to install. It has 10mm axles, so there is no filing of the dropouts. Attaching the torque arm to the stay is done with a couple of hose clamps. You will need a cassette removal tool and a chain whip to transfer the cassette from your old wheel to the GMAC wheel or you can just pay a bike shop a few dollars to do it. That is a five minute job if you have the tools. You can get the tools for under $20.

MTA: That is assuming that your old wheel uses a cassette and not a freewheel. Otherwise, you can order the wheel with a cassette with the right number of cogs. You should also readjust the rear derailleur, which is an easy task that lots of Youtube videos will show you how.
Thanks for this. Reading it out like that gives me a bit of confidence. I think installation and maintenance is what initially ruled out mid-drives for me. I'll have a look at some general youtube videos.

E-HP wrote:
Jun 05 2021 12:01pm
Looks like the GMAC 10T would meet your specs:
https://ebikes.ca/tools/simulator.html? ... &grade_b=7

Can do 7% for 17km before overheating (your spec 5km)
Can do 31.7kph, higher when fully charged (your spec 32kph)
With 36V 17Ah, will go 50km (your spec 40-60km)
Supports regen

If you would relax your spec of no more than 32kph, then I'd go for the 8T. Twice to torque at 32kph as the 10T, so will accelerate to 32kph more quickly and still meets your other specs (if you back off the throttle and ride at 32kph):
https://ebikes.ca/tools/simulator.html? ... &grade_b=7
Just to confirm, the faster 8T will give me more torque which translates to a quicker acceleration to my max speed. I am open to relaxing my spec of no more than 32km/h but I am having trouble understanding why the 8T wouldn't work if I kept the speed limit in place.

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Re: Help decide between All-Axle and GMAC

Post by RunForTheHills » Jun 05 2021 1:46pm

irf23 wrote:
Jun 05 2021 1:04pm
Just to confirm, the faster 8T will give me more torque which translates to a quicker acceleration to my max speed. I am open to relaxing my spec of no more than 32km/h but I am having trouble understanding why the 8T wouldn't work if I kept the speed limit in place.
No, it is the opposite of that per the Grin motor simulator, but your max speed will be higher with the 8T vs 10T.

https://ebikes.ca/tools/simulator.html? ... nt_b=BRL10

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Re: Help decide between All-Axle and GMAC

Post by Tommm » Jun 05 2021 3:22pm

irf23 wrote:
Jun 04 2021 5:50pm
Hey All,

I am looking to join the eBike world by building my own so I have been doing some research. I have narrowed my kit down to the motor selection, and I wanted some insight or opinions.

The things I really wanted:
- Light
- Well Built
- Easy to Install
- Low Maintenance
- Regenerative Braking
- Serves my use case well

It's the last thing that I find so subjective.
Here's what I have for my use case:
40-60 km range
up to 5km of 5-7% hills (Vancouver. BC)
Up to 32 km/h but not more
90% of the time spent on pavement

So far I have decided on a 36V 17Ah battery with a Baserunner. I am caught between the Grin All Axle and the GMAC. Would the All Axle be good enough for what I want to do? Is the GMAC just the obvious choice for me?

I have attached screenshots of the two setups. Note I added the Phaserunner instead of the Baserunner because the battery I want isn't in stock so I offset the price.

I also wanted any opinions if it's possible to have a Hybrid as an ebike or if I should stick with converting the MTB. Also attached pics.

Thanks for reading.
That thing costs a fortune for quite bad performance... baserunner is like 40a, with 36v battery.
Really if that is all you need I would get a pedelec and unlock region to america, and you will have 32kph, and a warranty.

If you want a hub with throttle, I will show you a 5x better deal:
https://www.aliexpress.com/item/4000838391101.html
Option I recommend: Color: 48V24AH LCD3
It has 1.1kwh battery. 48v and 40a. 1/3rd the price. Top speed is about 42kph so still in your ballpark. It will wheelie from 0 if you want.

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spinningmagnets   100 GW

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Re: Help decide between All-Axle and GMAC

Post by spinningmagnets » Jun 05 2021 3:27pm

The lower turn-count uses thicker wire, and shorter windings, so it has less resistance.

It may have a higher top speed per pack voltage when using max throttle, but you aren't required to travel at the top speed.

There are several ways to cap the top speed to a speed you choose, so you don't have to constantly fiddle with the hand-throttle, orr PAS settings.

I would recommend the 8T over the 10T, but either one will work fine.

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Re: Help decide between All-Axle and GMAC

Post by E-HP » Jun 05 2021 6:57pm

Just to confirm, the faster 8T will give me more torque which translates to a quicker acceleration to my max speed. I am open to relaxing my spec of no more than 32km/h but I am having trouble understanding why the 8T wouldn't work if I kept the speed limit in place.
8T will go faster than 32kmh. Not sure why you want it to be limited to 32kmh (is that your legal limit?), but if you need to to be limited, you can just set the max speed in the controller settings.


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Re: Help decide between All-Axle and GMAC

Post by JackFlorey » Jun 05 2021 7:52pm

spinningmagnets wrote:
Jun 05 2021 3:27pm
The lower turn-count uses thicker wire, and shorter windings, so it has less resistance.
But also less torque at the same current. There is no difference in power handling between them; the only real difference it makes is in top speed vs. battery voltage. The simulator is a good way to see what sort of turn motor works at a given voltage/speed target.

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Re: Help decide between All-Axle and GMAC

Post by irf23 » Jun 05 2021 8:29pm

Tommm wrote:
Jun 05 2021 3:22pm
That thing costs a fortune for quite bad performance... baserunner is like 40a, with 36v battery.
Really if that is all you need I would get a pedelec and unlock region to america, and you will have 32kph, and a warranty.

If you want a hub with throttle, I will show you a 5x better deal:
https://www.aliexpress.com/item/4000838391101.html
Option I recommend: Color: 48V24AH LCD3
It has 1.1kwh battery. 48v and 40a. 1/3rd the price. Top speed is about 42kph so still in your ballpark. It will wheelie from 0 if you want.
My concerns with AliExpress are a) weather resistance b) quality and then no regen braking with this gear hub. I do quite get your point though. I can save $400-500 looking at some of the Grin FH212 and G310 setups.
spinningmagnets wrote:
Jun 05 2021 3:27pm
The lower turn-count uses thicker wire, and shorter windings, so it has less resistance.

It may have a higher top speed per pack voltage when using max throttle, but you aren't required to travel at the top speed.

There are several ways to cap the top speed to a speed you choose, so you don't have to constantly fiddle with the hand-throttle, orr PAS settings.

I would recommend the 8T over the 10T, but either one will work fine.
E-HP wrote:
Jun 05 2021 6:57pm
8T will go faster than 32kmh. Not sure why you want it to be limited to 32kmh (is that your legal limit?), but if you need to to be limited, you can just set the max speed in the controller settings.


Sent from my iPhone using Tapatalk
Makes sense. Thanks. I would consider the 8T over the 10T for sure.

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Re: Help decide between All-Axle and GMAC

Post by goatman » Jun 05 2021 9:00pm

if grins building the wheel for you then you wont have to worry about much in the way of broken spokes and warped rims

if something happens and they dont reply to emails, you can show up at their front door :D

id go gmac, its rear tire and has regen

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Re: Help decide between All-Axle and GMAC

Post by spinningmagnets » Jun 05 2021 9:06pm

But also less torque at the same current
The question is, does it make enough torque to make the OP happy on his particular commute. You can just as well say that the higher turn-count makes less top-speed at the same current...

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Re: Help decide between All-Axle and GMAC

Post by TDB » Jun 06 2021 3:55am

irf23 wrote:
Jun 05 2021 8:29pm

Makes sense. Thanks. I would consider the 8T over the 10T for sure.
I'd select 8T GMAC at 36V you selected. It'll better low end torque than DD. It is good to have a motor a little faster than what you'd have at rated voltage. Wheel RPM is proportional to voltage. You want about 25% margin to maintain pace near the end of the trip and pack voltage is dropping to around 30V. 10T with 48V.
I suggest phaserunner set something like 20A battery current limit and 70A phase current limit. Baserunner was mentioned somewhere, but isn't rated for the higher phase current requirements of that motor.

Many here disregard the law, that's fine, but I'll just say it anyway. You have a generous 32kph and 500W legal limit in BC. From your stated desire for 32kph limit I assume you want to keep it close to legal. At least to avoid ticketing and perhaps protect insurance. 16A at rated voltage is about your legal power limit. I'd set the controller current limit at 20A and power limit at 580W for when the battery is below rated. That is based on Grin Motor Simulator model. 500W will give you about 24kph on 7% at 100kg total mass with a (reasonably fit, but not racer) human input of about 150W.
Unfortunately CA is not smart enough for rpm based power limits that could allow 500W to the road at most speeds. Fatter torque curve of the GMAC is advantageous.
If you are trying to protect insurance it is a good idea to add a simple PAS sensor (it is required) to your shopping list and set absolute speed and power limits in the controller, not CA. It will give law and insurers less against you especially if it becomes a disability compensation fight where you could be left with nothing.

https://ebikes.ca/tools/simulator.html? ... &temp_b=34

Also ignore the maximum temperature in the Grin motor simulator (redline is too high anyway) and use the trip simulator instead. It'll give you a better idea of real world temperatures. You can use a Cycle Analyst and/or Phaserunner for power roll back at something more reasonable like 90-100C and 100-110C cut off. Lower is better for motor longevity.
Last edited by TDB on Jun 06 2021 8:20am, edited 1 time in total.

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Re: Help decide between All-Axle and GMAC

Post by spinningmagnets » Jun 06 2021 7:31am

All of the options discussed will work fine for the commute you described. I'd recommend 48V over 36V for several reasons. If you use a modest amount of power, the higher volts will mean that you use fewer amps, and the heat from amps are the issue of concern over the years. In a power outage, the 48V battery can run a small inverter, the 36V cannot.

You can cap the top speed with the cycleanalyst if you fear you might go too fast when you are not paying attention. The lower resistance of the 8T over the 10T is worthwhile, and I suspect that the only place anyone would feel a difference is if you use max throttle with the two of them side-by-side in a race. By that I mean, a poster suggested the 10T would have more torque at the same current. Would you use max current with either choice?

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Re: Help decide between All-Axle and GMAC

Post by TDB » Jun 06 2021 7:47am

The difference between temperature models for 36V and 48V set ups being discussed are negligble... A couple of degrees across the speed range at a given power level.
I assume Grin has modelled their products accurately.

https://ebikes.ca/tools/simulator.html? ... bopen=true

I think 48V does have better forward options.

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Re: Help decide between All-Axle and GMAC

Post by Tommm » Jun 06 2021 9:27am

irf23 wrote:
Jun 05 2021 8:29pm
Tommm wrote:
Jun 05 2021 3:22pm
That thing costs a fortune for quite bad performance... baserunner is like 40a, with 36v battery.
Really if that is all you need I would get a pedelec and unlock region to america, and you will have 32kph, and a warranty.

If you want a hub with throttle, I will show you a 5x better deal:
https://www.aliexpress.com/item/4000838391101.html
Option I recommend: Color: 48V24AH LCD3
It has 1.1kwh battery. 48v and 40a. 1/3rd the price. Top speed is about 42kph so still in your ballpark. It will wheelie from 0 if you want.
My concerns with AliExpress are a) weather resistance b) quality and then no regen braking with this gear hub. I do quite get your point though. I can save $400-500 looking at some of the Grin FH212 and G310 setups.
a, Weather resistance is fine in these ones, at least for the motor and controller. Their hailong is the same type of battery the grin has, if one is weather resistant the other one will be too.
Quality is also fine, I have done my research before getting this motor and I haven't seen a single fail. Motor cable is a bit long but you can shorten it in an hour. You wouldn't be saving $500, you'd be saving $1000 as it includes the battery too. Look at the last pic in the listing, they ship free and also are tax free in a whole list of countries.

b, No regen. (This can be fixed by a welder in 10 minutes, possibly would need a different controller.)
I own mid drives, this geared hub, and direct drive hubs. I can tell you the advantages of having regen on a light and slow bike are miniscule. Have you pedaled a direct drive hub with the motor off? Now do you understand a geared hub will have the motor spin 5x faster, so the resistance will be way more too. If you plan on pedaling or using PAS a lot the constant engagement of the magnets and reduction will net you comfortably in the negative range in energy consumption compared having no regen and freewheeling.

I think grin products are good (I have several) but to price an entry level spec kit to what you can get a more powerful and much longer ranged full build for, including a full suspension brand named donor bike is not something that should be encouraged. I sometimes have a laugh at their configurators and their markups.

In your place I would sell the bike in the pic and do exactly the above, for the same budget. I never understood putting $2000 worth of electronics on a bike worth $50 (mtb), the handling, capability, control, safety just won't be there. I bike with such budget should send you flying when hitting a pothole (hybrid) or get its rear rim destroyed (hardtail mtb).
Last edited by Tommm on Jun 06 2021 9:41am, edited 2 times in total.

TDB   100 W

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Re: Help decide between All-Axle and GMAC

Post by TDB » Jun 06 2021 9:37am

Counter argument...

Buy once.

With consumer protections.

And support your local businesses.

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Re: Help decide between All-Axle and GMAC

Post by Tommm » Jun 06 2021 9:44am

Yes, but not at all costs. They can support you because they can build 3 of these kits for the price they sell 1 for. They don't even give discounts compared to getting all of the parts separate for some reason??? :lol:

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Re: Help decide between All-Axle and GMAC

Post by TDB » Jun 06 2021 10:46am

So you want to live in a first world country and earn a first world wage, but pay third world prices. It is no surprise your jobs are going to Asia.

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Re: Help decide between All-Axle and GMAC

Post by Tommm » Jun 06 2021 1:47pm

TDB wrote:
Jun 06 2021 10:46am
So you want to live in a first world country and earn a first world wage, but pay third world prices. It is no surprise your jobs are going to Asia.
I want them to be competitive and fight for it. I think the grin ecosystem is about overcharging people 2-10x for things they have made/ buy themselves from china...

The asi controllers, also from canada are very competitive in price when bought through a dealer against pure chinese sabvotons/kellys on the higher end for example, and a superior product at the same time.

In the end, it's his money, his bike. I just showed some options and gave some answers when he raised some concerns.

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