What is the difference between 80nm of torque on a hub motor(cadence sensor) compared to a 80nm of torque on a MD (torque sensor)

[cstmichael]

I have a cadence sensor on my 750w Bafang G06 series hub motor that puts out 80n.m of torque. Will there be a noticeable difference on climbs if I get a Bosch 250W torque sensing mid drive motor with 85n.m of torque?

 

[Stefan Mikes]

I promised myself to not take part in the mid-drive vs. hub drive discussions
Ask yourself a question why all premium e-MTBs use 250 W (nominal) mid-drive motors and mountain gearing. Needless to say peak power of such motors is far higher than the nominal.

 

[jabberwocky]

The main difference between any hub drive and any mid drive is a hub motor is basically a singlespeed, with all the drawbacks that entails. On a climb, even with equal (or more) power, it can struggle because its gearing isn't letting it apply that power efficiently. Like trying to accelerate a stick shift car uphill in 5th gear, or trying to pedal away from a stoplight in a high gear.

Mid drives put the motor at the same place you pedal, so the power goes through the drivetrain and you can control the gearing. So power tends to be applied much more efficiently.

 

[fooferdoggie]

there was a video of one bike company that was able to compare a bafang 750 watt hub and a bafang 750 watt mid drive on the same bike it really showed the difference. may be worth a search. I think it was posted here but cant remember for sure.

 

[Petropoliskhan]

I promised myself to not take part in the mid-drive vs. hub drive discussions
Ask yourself a question why all premium e-MTBs use 250 W (nominal) mid-drive motors and mountain gearing. Needless to say peak power of such motors is far higher than the nominal.

Most, not all, premium bikes !

 

[Petropoliskhan]

The main difference between any hub drive and any mid drive is a hub motor is basically a singlespeed, with all the drawbacks that entails. On a climb, even with equal (or more) power, it can struggle because its gearing isn't letting it apply that power efficiently. Like trying to accelerate a stick shift car uphill in 5th gear, or trying to pedal away from a stoplight in a high gear.

Mid drives put the motor at the same place you pedal, so the power goes through the drivetrain and you can control the gearing. So power tends to be applied much more efficiently.

I think your forgetting to mention the loss of torque/ power when it goes through the transmission...
As discussed countless times on this very forum , different types of hub motor each have situations where they're more efficient ( trail vs gravel vs commute. Mainly flat vs hilly etc...)

 

[JCofMN]

there was a video of one bike company that was able to compare a bafang 750 watt hub and a bafang 750 watt mid drive on the same bike it really showed the difference. may be worth a search. I think it was posted here but cant remember for sure.

See:

Not exactly an apples to apples example, but informative nonetheless,

The key is torque at the rear wheel, i.e., how much torque from the motor ends up transferred from the drive tire to the ground. Assuming the specified torque is the static starting torque at the output
shaft for a mid drive, then the torque would be roughly multiplied by the transmission gear ratio used, whereas with a hub motor, the only variable for the motor's torque is the wheel diameter. It's interesting
that Bakcou doesn't think too highly of dual drive systems for their specific hunting bike market.

 

[billmeek]

there was a video of one bike company that was able to compare a bafang 750 watt hub and a bafang 750 watt mid drive on the same bike it really showed the difference.

This one?

 

[Petropoliskhan]

I have a cadence sensor on my 750w Bafang G06 series hub motor that puts out 80n.m of torque. Will there be a noticeable difference on climbs if I get a Bosch 250W torque sensing mid drive motor with 85n.m of torque?

I am sure your Bafang G06 is a fine bike but you must also take into account how that power is handled by the controller /battery/ motor combo.
I think it is also important to compare bikes that compete in similar price range. I think Bosch systems tends to be be (on average) more premium bikes.
And depends on what kind of climbs.

 

[Stefan Mikes]

Most, not all, premium bikes !

Name a premium e-MTB brand using hub-drives...

 

[fooferdoggie]

This one?

thats it thanks.

 

[Petropoliskhan]

Name a premium e-MTB brand using hub-drives...

Hi Stefan, you're right about the "premium e-mtb's"
The OP didn't say he was asking exclusively about e-mtb's..

 

[jabberwocky]

I think your forgetting to mention the loss of torque/ power when it goes through the transmission...
As discussed countless times on this very forum , different types of hub motor each have situations where they're more efficient ( trail vs gravel vs commute. Mainly flat vs hilly etc...)

I mean, ok, but chain drives on bikes are about the most efficient transmission in existence. You're talking about a few percent at most. Its not like a car automatic thats taking a chunk of power away. As someone who spent years commuting on singlespeeds/fixies and weekends riding a geared road bike, the loss of power through a bikes drivetrain is basically imperceptible.

The main drawback of mid drives are that they are more complex and therefore more costly, and since they route power through the drivetrain they are going to put more wear and tear on it.

 

[ChezCheese:)]

Try them out in person. See how it feels on each one.

 

[ElevenAD]

Middrives are better climbers if your dealing with steep inclines, it does not matter if they are torque or cadence.

 

[rich c]

I won't talk about the hub vs mid drive either. If you printed out all the discussions here, you would print something the size of War and Peace. But on the cadence vs torque, the torque sensor ride is identical to a traditional bicycle ride. On the cadence you have to rotate the pedals some distance for it to kick on, and then use the motor interrupter on the brake handles to stop it or it will continue on after you stop pedaling. If the cadence is not brought on easily by the controller, you can get set back in your seat when it comes on. Torque does not do that. For a serious MTB ride, the cadence is horrible. You don't want to wait for the cadence sensor when you are balanced on big rocks or roots. You want instant response and you want a reaction to your foot pressure, not something like a switch being thrown by the cadence.

 

[Knife2Sharp]

I have a Rambo Krusader AWD, although it doesn't have walk assist, it sure had some torque while standing along side of it, giving her a bit of juice and trying to hold it back, the front wheel would lift up and start skipping. It has two 500w hub motors and their site says 160nm of torque, whereas my Bushwacker w/750 watt Bufang BBSHD mid-drive is 120nm. For off-road use, it's awesome, but does suck w/PAS on inclines - I'm doing most of the work. Maybe the next big thing will be AWD + mid-drive

I should also note, with the AWD, traction is much better. There was a muddy field and while on the Bushwacker, I turned a corner and the backend spun out, just like a rear wheel drive car in the winter. I took my Krusader down along some RR tracks near one of my hunting properties and came to a section where there was nothing but close brush next to the track, and I was able to ride along on the side of the rock slope about halfway up - one of those situations where momentum was keeping me from sliding down and not slowing down.

So I don't necessarily agree with Bakcou's opinion about AWD drive bikes, for off-road driving on flat and hilly terrain, where an ultra mid-drive may be a bit overkill, I would rather have the AWD bike, even if battery life suffers, IMO.