torque sensing vs gear sensor

[DuckMtnDick]

As I have some intermittent ache/pain in my leg, I have been looking at a Bafang likely a BBS02 with a gear sensor. This because I'm led to believe this will decrease any jarring with shift changes. However I have noticed the CYC Photon has torque sensing that appears interesting.
Interested in the thoughts of others,
Thanks

 

[tomjasz]

Two different functions. Torque-sensing "reads" your energy output and adjusts engine power. A gear sensor simply shuts down the motor momentarily during the actual chain movement to another sprocket.

I never found shifting to be jarring with or without a gear sensor.

 

[harryS]

The term for the BBS02 pedal assistance is cadence sensing, The motion of the pedals, if it meets a certain rotation speed, is used as an on/off switch to turn on the motor, The speed of your pedaling has no effect nut, the motor speed will depend on the level of pedal assist chosen. If you have an assist level that matches how fast you want to ride, it can feel like riding a regular bike,
.
A torque sensor system measures the above pedal pressure and provided notor assist based on the pressure. The better systems also take into account how fast you spin the pedals and adjust power accordingly, I own bikes with both types of pedal sensing. Both have their pros and cons.
.
One difference between the two is when starting out on a bike, The cadence system needs to see the pedals rotate at least a half revolution before giving power. The torque assist system gives you power as soon as it feels enough pedal force,
.
Another difference is in climbing a hill. If you run out of steam on a cadence bike, you have to go to a higher assist level to get more power, if that's available, On a torque sensor, it will give it to you if your pedal harder, if there is any more power left.. In both cases, if there's no more power in reserve, well then you fall over, if you ride like my wife. I don;t know how she does that.
.
The gear sensor on a bafang is not required for normal riding, and has little to do with the above discussion,. You can have situations with both systems where you want a gear sensor, I guess if you had one, you could downshift on that hill without having to kill the motor manually. The sensor would do it, while you fall over,
.

 

[AHicks]

I have, ride, and enjoy both the "cadence only" and the "torque sensing" bikes. All are equipped with throttles as a bike without one is a complete deal breaker here. Just NOT going to happen. Noteworthy, is the fact that ready built/production bikes with torque sensing are generally quite a bit more expensive than the cadence only bikes.

There should be no "jarring" on a shift change with either system - but a lot of that's going to depend on the skill level of the rider. It's going to take some riding to get the timing required for those smooth perfect shifts. They may be a little clunky at first for a newbie or somebody without recent experience.

Last, if you are still exploring your power options, just wanted to mention that Bafang has a great motor that's made/is making a lot of friends. It's torque sensing AND able to be throttle equipped. Check into bikes powered with the Bafang M600 motor.

 

[rich c]

I think he is asking about shift sensing Harry, but maybe not. I think you just need to easy up on the throttle when you shift Duck and shift it like a bicycle instead of a motorcycle. I'm led to believe this will decrease any jarring with shift changes

 

[gromike]

Maybe shift the bike like you're driving an old tractor.

 

[harryS]

"Got to be cool now, power shift here we go" from "Shut Down" Brian Wilson & Roger Christian. 1963
.
OK, it's been 60 years. The Beach Boys lost that race, and probably blew the transmission on that fuel injected Sting Ray, shifting with the pedal to the floor,
.
Gear sensors cut the motor while you shift, letting the derailleur move the chain. If you're an old time biker, you already know to do that.
.


.

 

[AHicks]

"Got to be cool now, power shift here we go" from "Shut Down" Brian Wilson & Roger Christian. 1963
.
OK, it's been 60 years. The Beach Boys lost that race, and probably blew the transmission on that fuel injected Sting Ray, shifting with the pedal to the floor,
.
Gear sensors cut the motor while you shift, letting the derailleur move the chain. If you're an old time biker, you already know to do that.
.


.

Totally agree with you Harry. Would only note that some of the Bafang Ultra guys, even those with recent analog experience, are struggling with their timing a bit when first stepping on to thier new Ultra powered bike (most are standard w/shift sensors).

Personally, the only time I notice that switch is the unusual condition where you are trying to downshift at a fairly low speed and low cadence (you've found yourself going way too slow in way too high a gear for what you have right in front of you). It's not hard to stall a bike with that switch! MUCH better move with an Ultra (and likely a BBSHD), because of the huge amount of torque on tap, is to increase the power available by hitting the PAS level "UP" button a time or 2..... no delay on this plan, and it won't hurt a thing. -Al