Torque or speed sensor - preferences?

[trex]

you can't have torque sensor and throttle active at the same time, it's either.

 

[falmouthtony]

Ho-hum...
Yet another thread with no hope of depolarising opinions
But I'll add my two-penn'orth:

Recently, my mate from down west & I wobbled off over to Lanhydrock for a bumble round the blue trails.
He has a shiny new Cube 29er with the performance Bosch system & I was on the Mamba 29er with Ezee kit.

On the 18-mile return ride along (very) minor roads, I totally blew him away on every uphill section, using level 3 assist (to15mph) & he was easily as quick as me on the occasional flat sections when I was using level 2 (assist to 11mph).

Can't comment on relative performance on the singletrack, as I seemed to lose contact with him quite quickly
However, he was right behind me on the fast downhill sections of the Timber Trail; until we encountered horseflies, to which he's allergic, and I had trouble keeping in contact with him on the loong uphill drag back to the cafe!

Discussion over coffee suggested he was using quite low levels of assist Most of the time & fiddling about a lot, as it's a new bike, whereas I bung mine in level 2 & leave it there, using gears 4&5 only.

10 minutes for the 2-mile & 4+ for the 1-mile suggest about 12mph, meaning I had some level of assist most of the way round on the bits where I was pedalling.

I would suggest the Bosch system only rewards effort: What you put in is returned 2.75 times (max.) You only have respite on easy flat & downhill, but the bike is light, agile & easy to pedal unassisted.

The Ezee hub drive adds its power to mine as my speed decreases; ie going uphill: This is where I need assist & feels totally natural to me, just the hills decrease in severity. The kit feels heavier & not so well balanced, but in no way moped-like. Anyone who thinks otherwise needs to ride the Cornish Alps to gain a balanced view.

Would I want a torque-based system? No thanks: My bike has become my main form of local (20 miles or less) transport - I don't regard it as sport: If I did, I'd get a "proper" bike & stop cheating.

As Jackhandy's mate with the shiny new 29er, here's my two penn'orth also.
First and foremost, if horsefly bites upset you as much as they do me, you can get ANY bike up to top side of 20mph to get away from them!!

Seriously though, I can agree with pretty well everything said in JH's post.

What I can say quite categorically, having both types of bike, is that neither is 'right or wrong', 'good or bad'. They are totally different riding experiences.

The Bosch CD Cube bike is relatively light, well balanced, looks the part, will cope admirably with serious steep rocky descents, delivers power in a subtle way, feels well engineered and responds totally to the effort I put in. In the short time I've had it, I've thoroughly enjoyed it, particularly on the rough trails. Having said all that, there is no question that overall it gives me far more of a work out, particularly on the hills, than the Ezee conversion on my Specialized Hybrid road bike with rigid forks, 700c wheels and thinnish tyres. Quite simply, IT'S HARDER WORK.

The converted Ezee kit road bike is a gem. Recently I rode the 95 mile Dartmoor Cycle way with it over two days. Mostly very seriously hilly narrow lanes with a total climb in excess of 9500 feet over the two days. Even in the scorching hot weather I was able to thoroughly enjoy the scenery and arrive at the b & b just pleasantly tired - not knackered!

So ..... which bike do I prefer?

Neither .. I love them both.

I would have found the Dartmoor ride really hard work on the Cube, which would have lessened my enjoyment of the experience. The pedal sensor system combined with the powerful Ezee motor on the Specialized road bike made for a very rewarding, hilly and lengthy, 'electric bike ride'.

Without the Cube Bosch system bike with it's silky performance and totally controllable power output when used correctly, I would miss out on the exhilaration my lumpy bumpy rides and hairy steep descents down narrow boulder strewn tracks through the bracken. Makes me feel a lot younger than 67, and allows me to do stuff that health issues preclude without a modicum of assistance. I do feel you have to 'think' more about what you're doing on this bike. This will appeal more to some riders, less to others.
I feel I'm riding a 'normal good quality mountain bike' most of the time.

I've ridden around 15 miles on each bike today. Very different rides. Very different stile of riding. Both as enjoyable as each other. A good day!

 

[jackhandy]

Well written, Tony:

I reckon we've both been very restrained in voicing our uneducated opinions

Unlike some of the,practically bigotted, tub-thumpers on here.

See you tomorrow.

By the way - You didn't mention whether you find the hub- drive bike "Moped-like"...

 

[Deleted member 4366]

I think Tony has explained it pretty well. I reckon that you can broadly divide into two camps. There'll be a bit of overlap, but lets see what this controversial statement brings:

If you wear jeans or a skirt when riding, you'll probably prefer to ride a bike with a speed control system. If you wear lycra and/or cycling shoes while riding, you'll probably prefer a torque multiplication control system.

Note that some bikes with torque sensors have a speed control system. They only use the torque sensor to detect pedalling, so it's the whole control system that should be the decision factor, not the type of sensor.

 

[Geebee]

I think Tony has explained it pretty well. I reckon that you can broadly divide into two camps. There'll be a bit of overlap, but lets see what this controversial statement brings:

If you wear jeans or a skirt when riding, you'll probably prefer to ride a bike with a speed control system. If you wear lycra and/or cycling shoes while riding, you'll probably prefer a torque multiplication control system.

Note that some bikes with torque sensors have a speed control system. They only use the torque sensor to detect pedalling, so it's the whole control system that should be the decision factor, not the type of sensor.

Fail on the first step , if I was well I would be looking for a good torque system, I still eye them off even though I know I can't ride one anymore.
I wear jeans or shorts (it gets hot down here in summer), I don't own any lycra but do wear clipless shoes on the trikes to avoid leg suck.

 

[Artstu]

Jeans and trainers on my Bosch, or shorts if it's really warm.

Oh and for someone who said they appeal to those in flat areas, I live in the Peak District in the south pennines, which is the opposite of flat.

 

[shemozzle999]

I don't know how the Bosch or Impulse system works and I only have a limited idea about the Panasonic since it isn't easy to take it apart.

The Panasonic system measures torque about the the shaft which joins the pedal cranks on either side of the bike. I suppose this would be the bottom bracket on a conventional bike. I assume it does this via a system of strain gauges or something similar. The torque value is fed into the control system, which also measures the pedal cadence, so from those two inputs it's easy for the system to determine how much power the rider is contributing. The rider can then set a factor by which his effort is multiplied.

So does the motor power directly mirror the riders input with oscillating power?

If you take the driven wheel off the ground set the lowest multiplier and very slowly turn the pedals by hand can you detect the motor pulsing the wheel and is it also noticeable by the rider when riding on the highest multiplier setting at a low cadence?

As the pressure is applied by the right foot of a rider in a downwards clockwise direction I assume the torque is generated in a half wave sinusoidal patten starting at zero at the top of the stroke to a maximum torque occurring when the pedal is in the three o clock position then reducing back to zero at the bottom of the stroke where the left foot takes over and repeat the process on the left hand anti clockwise turning pedal thus producing a resultant torque sensor output of a continuous series of half waves at a frequency of twice the riders cadence with the peak amplitude varying with the riders effort .

What the torque controller does with it I have no idea at present.

It has been mentioned elsewhere that a torque reference point must be factory set by loading the pedal in the 3 o clock position with a known weight to calibrate the system. With the reference point known the multiplier can be accurately applied via the software.

To increase the multiplier without requiring additional power above the permitted allowed I can only think that it can be achieved by shortening the crank length reducing the riders input, resulting in a finer response to riders input but no additional power output.

 

[Deleted member 4366]

... if I was well I would be looking for a good torque system,
..... but do wear clipless shoes on the trikes to avoid leg suck.

You therefore fit perfectly into my model.

On the panasonic system: To me, it seemed to be a very direct torque multiplication system. You can feel it when climbing slowly with a low cadence. As you press on the pedal, you get a surge from the motor that dies as you get to the bottom of the stroke. Other systems, like Bosch, smooth out that effect. I would guess that the Bosch has a combination of speed control and torque control algorithms in its control system

 

[tillson]

So does the motor power directly mirror the riders input with oscillating power?

If you take the driven wheel off the ground set the lowest multiplier and very slowly turn the pedals by hand can you detect the motor pulsing the wheel and is it also noticeable by the rider when riding on the highest multiplier setting at a low cadence?

As the pressure is applied by the right foot of a rider in a downwards clockwise direction I assume the torque is generated in a half wave sinusoidal patten starting at zero at the top of the stroke to a maximum torque occurring when the pedal is in the three o clock position then reducing back to zero at the bottom of the stroke where the left foot takes over and repeat the process on the left hand anti clockwise turning pedal thus producing a resultant torque sensor output of a continuous series of half waves at a frequency of twice the riders cadence with the peak amplitude varying with the riders effort .

What the torque controller does with it I have no idea at present.

It has been mentioned elsewhere that a torque reference point must be factory set by loading the pedal in the 3 o clock position with a known weight to calibrate the system. With the reference point known the multiplier can be accurately applied via the software.

To increase the multiplier without requiring additional power above the permitted allowed I can only think that it can be achieved by shortening the crank length reducing the riders input, resulting in a finer response to riders input but no additional power output.

Yes, the Panasonic system does mirror the rider input and when climbing a steep hill in a low gear, so pulsing is noticeably.

Turning the pedals by hand with the back wheel off the ground doesn't generate sufficient torque to activate the motor.

 

[shemozzle999]

Thanks, I can now understand why the the motor maximum peak power is allowed to exceed what would normally be permissible as the averaging out of the waveform would bring it back inline with the regulations. As long as the waveform is not allowed to clip I see nothing wrong with this approach.
Does your bike also have a separate speed sensor?

 

[tillson]

Thanks, I can now understand why the the motor maximum peak power is allowed to exceed what would normally be permissible as the averaging out of the waveform would bring it back inline with the regulations. As long as the waveform is not allowed to clip I see nothing wrong with this approach.
Does your bike also have a separate speed sensor?

On the 26 Volt early Panasonic motors, the speed is detected via the sprocket which drives the chain. This sprocket is on the end of the motor output shaft. This means that when in a low gear, the motor cut off occurs before 15 mph is reached. This is because the motor output shaft is rotating at cut off speed even though road speed is below 15 mph due to the gearing.

On the later 36 Volt systems, road speed is used, via a magnetic pickup, to determine the motor cut off point (15 MPH in all gears. )

 

[shemozzle999]

OK, thanks again that has made it clear for me to understand.

I looks like there is no power control delivery advantage over one system or another , just down to rider preference.

Your torque system provides a wholly pulsed delivery and a PAS or throttle system provides a constant motor assist overlaid with a natural pulsed rider input from the crank.

 

[falmouthtony]

I think Tony has explained it pretty well. I reckon that you can broadly divide into two camps. There'll be a bit of overlap, but lets see what this controversial statement brings:

If you wear jeans or a skirt when riding, you'll probably prefer to ride a bike with a speed control system. If you wear lycra and/or cycling shoes while riding, you'll probably prefer a torque multiplication control system.

Note that some bikes with torque sensors have a speed control system. They only use the torque sensor to detect pedalling, so it's the whole control system that should be the decision factor, not the type of sensor.

Wrong again d8veh!!

Don't possess any lycra or cycling shoes.
Shorts or Ron Hill tracksters and Merrell sandals ( without socks of course!!) on both ..... and the damage to the calves from the pedal studs to prove it .

 

[Deleted member 4366]

Wrong again d8veh!!

Don't possess any lycra or cycling shoes.
Shorts or Ron Hill tracksters and Merrell sandals ( without socks of course!!) on both ..... and the damage to the calves from the pedal studs to prove it .

Are you sure? What about your lycra underpants?

 

[D8ve]

D8veh

What do I do then on Monday I wore jeans and t shirt. Today it was Lycra ? Confused of Bristol ;-)

 

[Deleted member 4366]

The fact that you wear lycra any time puts you in the torque control camp, I'm afraid, with Falmouthtony and his lycra underpants.

 

[D8ve]

Tony are we allowed to discus some one else's Lacey undergarments?

 

[jackhandy]

The fact that you wear lycra any time puts you in the torque control camp, I'm afraid, with Falmouthtony and his lycra underpants.

Oh dear, oh dear...

All I can say is that I've never been one of the herd - In fact, if I had any money I'd be described as Excentric but, as a skint pensioner, I'm just another crackpot

I wear lycra shorts under me Aldi casual shorts & I'm definitely of the Speed Sensor persuasion!

They ain't 'alf comfy

 

[Artstu]

It's no good anyone attempting to pigeonhole us electric bike owners, we're all eccentrics who aren't constrained by the need to belong.

Unsurprising that we often also have widely differing opinions about things. Strength of character is required to live as we often do,

 

[Deleted member 4366]

It's not about pigeon-holing. It's about observation, normal distributions, probability and correlation.