Hub motor for 26” wheel commuter ?

[Ocelot]

I want to put a hub motor on my Trek 4300 to make it my work commuter. Presently I have an Aventon Abound cargo bike, it’s great but it takes up a lot of room in the bike rack at work.
For the commuter, I’m hoping for 40 km range with a top speed of 45 to 50 km/hr for the short stretches where I have to mesh with car traffic, flat road no headwind, but that’s not a deal breaker.
Is anyone using a GRIN SX 2 or a Bafang G311 in this configuration and getting reliable performance with this ? Or, should I step up to the GMAC ?
Regen is not really a plus as it’s Manitoba (few hills where I’d use it, and potextra drag)

And my next question is can you use two different capacity batteries on a Reention battery base for those days where extra range is needed?

 

[neptronix]

SX2 sounds like the right motor. G311 too small. GMAC only if you need higher speeds or you have serious hills. SX2 is the most efficient hub motor of all them.

Batteries can be combined in parallel if the current state of charge and voltage curves match, otherwise you can use a battery blender type device, since you're not using regen.

 

[Ocelot]

SX2 sounds like the right motor. G311 too small. GMAC only if you need higher speeds or you have serious hills. SX2 is the most efficient hub motor of all them.

Batteries can be combined in parallel if the current state of charge and voltage curves match, otherwise you can use a battery blender type device, since you're not using regen.

Thanks
I have an unused DateX2 combiner, so dual batteries isn’t a huge stretch going forward.

The side cable exit of the Shengyi is just a tiny bit off-putting, but I’d have to imagine lots are on the road already.

 

[neptronix]

That's how hub motors have been made since the 2010's. Put a protector on the side ( it probably includes one ) and enjoy.
SX2 is a really nice motor otherwise.

 

[Ocelot]

That's how hub motors have been made since the 2010's. Put a protector on the side ( it probably includes one ) and enjoy.
SX2 is a really nice motor otherwise.

I ran a sim on the Grin motor simulator, there’s no hope of 45 km/hr but I like the 17 /km (27 wh/mile) efficiency calculation result. I’m at that with my Abound at 32 km/hr

 

[neptronix]

They have a fast winding you can use. Goes a bit above your requested top speed with a 48v battery and 26" wheels even.

 

[Ocelot]

I’m going to look into the fast wind for sure.
I’m still learning, I present a substantial aerodynamic load, but it still might be my best option

 

[ebike4healthandfitness]

For the commuter, I’m hoping for 40 km range with a top speed of 45 to 50 km/hr for the short stretches where I have to mesh with car traffic, flat road no headwind, but that’s not a deal breaker.

How short are the short stretches?

 

[Ocelot]

How short are the short stretches?

At most, a block or two.
I try to actively avoid high traffic areas, but I’ve found out first-hand that the best way to upset a motorist is to hold them up…. Even if for just a few seconds

 

[ebike4healthandfitness]

At most, a block or two.
I try to actively avoid high traffic areas, but I’ve found out first-hand that the best way to upset a motorist is to hold them up…. Even if for just a few seconds

When not going 45-50 kmh, how fast would you be cruising at?

Are you pedaling when cruising at this lower speed? If so, with how much effort? 100 watts?

 

[Ocelot]

No more than 30km/hr

Never more than 32 km/hour on a bike trail/path or MUP

 

[neptronix]

I’m going to look into the fast wind for sure.
I’m still learning, I present a substantial aerodynamic load, but it still might be my best option

Leaning forward on the handlebars can make a huge difference.
This motor can sustain 50km/hr for decent periods of time, 45km/hr probably indefinetely.

 

[gromike]

I laced this motor into a 26" wheel:
https://www.amazon.com/Rosyouth-100...0318&sprefix=bicycl+hub+motor,aps,189&sr=8-14 .

I have run it at 36v and it kicks ass!