still not to sure what to make of bosch ebike system

[basicasic]

I agree with RobF that you don't need a cadence of 90 (or anywhere near to get good assistance from a Bosch motor. Like he said a cadence of 50 or 60 is plenty. I find slogging in a high gear at a low cadence pretty fruitless and changing down a cog or two ups the cadence to a reasonable level and the power flows.

For people who are incapable of walking, incapacitated in some way or just too lazy to pedal then the Bosch system is not the one for you. If you can walk 'normally' (so you can pedal normally) then it will be just fine.

Incidentally, I tried turbo (and sport) out for the first time this morning and there was so much power I could have climbed the north face of the Eiger.; it was ridiculous.

 

[Woosh]

there was so much power I could have climbed the north face of the Eiger

that's a common impression when a fit person rides a modern e-bike. They are commonly fitted with 17A controllers, giving about 550W-600W maximum assistance.

 

[footpump]

hi all a bit better today went up steepish (for me) roads today ok in eco.
one particular a***hole of a slope got up in sport, almost to the top changed to turbo but did not notice any obvious increase in assistance .
I find that I am most comftable in and around 23 26 sprockets.
went up my regular route hill at 15mph ok although this is not a long hill.
only annoying thing rear indexing changed a couple of times without me switching gear.
have found I need to do a bit more gear changing rather than tending to sit in one gear

 

[anotherkiwi]

Yes you have to ride a mid drive like it was a bicycle...

 

[Emo Rider]

I will not recommend a torque bike to anyone that has any kind of physical impediment. I love my torque bike and would not trade it for a hub/cadence system. The pro hub drive posters here are fair in their comments as to riders whom are aged or otherwise physicaly impaired. What I do not see from them are objective comments about how to get the best from a torque system. I would not expect anything different as the two camps are divided.

It takes a good, no great dealer, that has both types of systems and can both explian the differences and fit the customer with the bike that fits their needs. In 8 pages of bantering between toque and cadence individuals and businesses, it appears to me that the OP was mis sold and did not have the torque system explained and demonstrated correctly. A cadence system might have been best for him. Peace all.

 

[Woosh]

What I do not see from them are objective comments about how to get the best from a torque system.

I did not make any comment about how to get the best out of a torque system but that does not mean that I dislike or consider it inferior in any way.
As a side remark, what comes out of the torque camp is often derogatory toward their opposite.

 

[asc99c]

It's dead simple: the faster you pedal in any one gear, the less torque you get. Every time you change down, the torque increases. Every time you change up, the torque decreases.

Only the torque affects hill-climbing, not power.

To go faster in any one gear, you have to pedal disproportionately harder when you get past say 60 rpm because of the decreasing torque from the motor.

I'm really confused by this, it's the exact opposite of my experience. The power curves I've seen online look correct to me: as you pedal faster, the effort required to pedal drops off dramatically as the motor assistance improves, up to somewhere around 90rpm (no cadence meter to say exactly, judging from cadence on exercise bikes).

Dropping a gear or two and pedaling faster, the bike will fly up a hill with very little effort. Unlike the op though, my own bike has only a 16t front sprocket, and a dinner plate sized 46t low gear on the back. I'm thinking of swapping the sprocket for a 20t, since I currently have only ever needed first gear on a very steep section of hill when the motor had died completely.

Sent from my ONEPLUS A3003 using Tapatalk

 

[Artstu]

As a side remark, what comes out of the torque camp is often derogatory toward their opposite.

More a case of correcting the continuous misinformation from posters trying to sell their bikes and swamping threads, certainly brings out the worst in me.

 

[Gubbins]

Nothing to do with your heart... cadance is about spinning your legs, not about the load / power that is being put through them.

My 70+ year old mum, who's just had hip surgery, can beat me up steep hills in the Cotswolds on a Bosch Active line bike, when I'm on my normal road race bike.

You have to ride them slightly differently to normal bikes, just spin, its not all about power from the rider, the motor does it for you.

In my experience spinning your legs has a lot to do with elevating your HR. A non athlete, especially one drawing a pension, will use most of their energy just to turn the padals. Something to do with slow and fast twich muscles I think. Anyway, without load on a trainer I have managed 120 rpm's for a very short time, which took my HR to the highest its ever been at 178 and 20 minutes ranging between 85 and 100 RPM's certainly gave me a sweaty workout with my average HR well over 140 .. And I consider myself to be a fitter than average 68 year old.
Having said that I like the way the bosch bike works with the power increasing with cadence....

 

[Woosh]

More a case of correcting the continuous misinformation from posters trying to sell their bikes and swamping threads, certainly brings out the worst in me.

Artstu, would you please list the misinformation that you accuse me of?

 

[mike killay]

It takes a good, no great dealer, that has both types of systems and can both explian the differences and fit the customer with the bike that fits their needs. it appears to me that the OP was mis sold and did not have the torque system explained and demonstrated correctly. A cadence system might have been best for him. Peace all.

To the average punter with no knowledge about ebikes, they all look much the same and said average punter is totally unaware that there are two radically different systems.
They just see hub or crank motors.
Bike shops have a huge responsibility to ascertain their customers needs and expectations.
(I must clarify that not all crank systems are torque sensored.)

 

[Gubbins]

To the average punter with no knowledge about ebikes, they all look much the same and said average punter is totally unaware that there are two radically different systems.
They just see hub or crank motors.
Bike shops have a huge responsibility to ascertain their customers needs and expectations.
(I must clarify that not all crank systems are torque sensored.)

Change the word punter to cyclist. At the one end of the scale is the pro with a finely balanced approach with man and machine fully in sync and can spin at 100rpm all day long, and at the other end is someone who rides with the saddle too low, the middle of his foot firmly planted on the pedals and turning a high gear at about 40 rpm.
My Yamaha powered ebike would be useless to the former as all it's power is at a low cadence wirh no help at 100+, whereas my Bosch powered bike wouldn't offer much help to the latter as pulling a high gear at a low cadence won't get you up the hills...

 

[Deleted member 4366]

I'm really confused by this, it's the exact opposite of my experience. The power curves I've seen online look correct to me: as you pedal faster, the effort required to pedal drops off dramatically as the motor assistance improves, up to somewhere around 90rpm (no cadence meter to say exactly, judging from cadence on exercise bikes).

Dropping a gear or two and pedaling faster, the bike will fly up a hill with very little effort. Unlike the op though, my own bike has only a 16t front sprocket, and a dinner plate sized 46t low gear on the back. I'm thinking of swapping the sprocket for a 20t, since I currently have only ever needed first gear on a very steep section of hill when the motor had died completely.

Sent from my ONEPLUS A3003 using Tapatalk

Your understanding s correct. There's no need to be confused. It's just your interpretation of the commets that is confusing you. You're getting confused between torque and power. The motor makes more power the faster you pedal, but the torque decreases. If you don't have enough torque for the conditions (steepness or speed), you slow down, so power decreases.

Power = torque x rotation speed. It's the torque that provides the power, so you should see it the other way round as torque = power/rotation speed.

If you compare that with the power graphs shown earlier in the thread, then do the sums, you'll see that you get diminishing returns of torque as you pedal faster. In order to pedal faster, you have to apply more torque yourself, so the total torque increases and you can climb steeper and go faster, but you're giving an increasing proportion of the torque once you get past about 60 rpm.

All that applies to staying in one gear. If you can change to a gear where you can pedal at 75 rpm, you get the maximum power from the motor with less torque from yourself. That's why you have gears. Obviously, if you're in bottom gear, that's not an option. You therefore have to make sure that you get gearing that suits your capability and the rides you do.

Most of my earlier comments assumed that OP was using bottom gear, like most of us would, but it seems he wasn't.

 

[Trevormonty]

My friend has just bought a Smartmotion Pacer, allows rider to switch between cadence a torque. He uses cadence on way to work avoid a sweat and torque on way home to get a workout, also good for extending battery range. Excellent purpose built commuter, lights up like christmas tree no missing it in dark and no speed restriction in NZ. Tops out at about 40km/hr. Does struggle on steep hills but that is price you pay for speed.

Sent from my SM-G570Y using Tapatalk

 

[Woosh]

to help understanding the issues, you need to take into account some ergonomic aspect. The cranks and pedals are obviously connected to the legs. The energy needed to rotate the cranks has to be added to the energy needed to move the legs. Pedaling at higher speed costs considerably higher amount of strength than you would rotating the cranks with your hands.
If you have a large tummy, you know exactly what I mean.

 

[Deleted member 4366]

I love my torque bike and would not trade it for a hub/cadence system. The pro hub drive posters here are fair in their comments as to riders whom are aged or otherwise physicaly impaired. What I do not see from them are objective comments about how to get the best from a torque system. I would not expect anything different as the two camps are divided.

Whether you are physically impared or just lazy, it should make no difference whether you choose a hub-motor or crank-drive. What they need is a control system that gives power-on-demand.

Don't forget that there's plenty of hub-motors that use torque multiplier control systems. Most of them use direct drive motors, which have their own advantages, but it seems that their disadvantages don't suit our style of riding, so they've never been popular here. The Wisper Torque, being a geared motor with a clutch, is an exception. It also gives you the posiblity to switch between torque and cadence control, so you can choose which suits you.

With a hub-motor, torque is independent of the bike's gears, so you need to choose a motor that has the right characteristics for your ride. Basically, you can't have good climbing torque and high speed with a low power motor. It seems that most people aren't even aware that you can get hub-motors that have substantial climbing torque. The typical hub-motors are available in a wide range of speeds, but typically, they use the 230 to 270 rpm versions, which would run to well over 20 mph, when unrestricted, at the expense of climbing efficiency. That doesn't make sense to me when they're restricted to 15 mph.

 

[Gubbins]

My 2 bikes have very different characteristics which I soon got used to. What I, as a cycling moron, like about both of them is the fact that they are more or less automatic in the way the electric bit works so I can just get on and ride them without thought. My giant/Yamaha is set to normal and the scott/Bosch is set to sport and after early experiments I rarely change these settings now. All this technical talk of torque and power graphs might as well be Chinese and I don't think I am in a minority either. No disrespect intended towards all you that have the knowledge, which I find impressive but often meaningless.

 

[Gaz]

All this technical talk of torque and power graphs might as well be Chinese and I don't think I am in a minority either.

Well if you are in a minority, then so am I, right there with you

Gaz

 

[Emo Rider]

Whether you are physically impared or just lazy, it should make no difference whether you choose a hub-motor or crank-drive. What they need is a control system that gives power-on-demand.

Don't forget that there's plenty of hub-motors that use torque multiplier control systems. Most of them use direct drive motors, which have their own advantages, but it seems that their disadvantages don't suit our style of riding, so they've never been popular here. The Wisper Torque, being a geared motor with a clutch, is an exception. It also gives you the posiblity to switch between torque and cadence control, so you can choose which suits you.

With a hub-motor, torque is independent of the bike's gears, so you need to choose a motor that has the right characteristics for your ride. Basically, you can't have good climbing torque and high speed with a low power motor. It seems that most people aren't even aware that you can get hub-motors that have substantial climbing torque. The typical hub-motors are available in a wide range of speeds, but typically, they use the 230 to 270 rpm versions, which would run to well over 20 mph, when unrestricted, at the expense of climbing efficiency. That doesn't make sense to me when they're restricted to 15 mph.

Couldn't agree with you more about the Wisper Torque. It is the everything bike.

 

[anotherkiwi]

In my experience spinning your legs has a lot to do with elevating your HR. A non athlete, especially one drawing a pension, will use most of their energy just to turn the padals. Something to do with slow and fast twich muscles I think. Anyway, without load on a trainer I have managed 120 rpm's for a very short time, which took my HR to the highest its ever been at 178 and 20 minutes ranging between 85 and 100 RPM's certainly gave me a sweaty workout with my average HR well over 140 .. And I consider myself to be a fitter than average 68 year old.
Having said that I like the way the bosch bike works with the power increasing with cadence....

I have fast twitch muscles and at over 60 have no problem spinning pedals at 80 rpm all day long without breaking a sweat (everybody sweats at +30°C like today). Walking, I am able to sustain 6 km/h for 8 hours with a 1/2 hour break every 2 hours. Because of asthma I can't go very far on a normal bike around here because on the hills I get bogged down even in the lowest gear and stuck in low cadence and there my heart rate goes sky high etc. etc. I find spinning over 90-100 rpm to be counter productive and that does get the heart rate up.

My unscientific testing shows that I don't use much over 290 W motor power (LCD watt meter) on the hills unless I am feeling lazy. And using on-line calculators have deduced that I am producing about 160 W (2 W/kg) on a good day which is very much in line with what a reasonably fit person is able of producing over sustained periods. I usually ride in 1 hour segments - from bar to bar...