still not to sure what to make of bosch ebike system

Artstu

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Aug 2, 2009
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hi all
not done any hills but today tried the lower gears 23 and the lowest 26 30 34
flattish but rising slightly, found in the 30 although seeming to be spinning the pedals quite fast and doing about 12mph the power meter was only about half way,

tour mode the meter just above the tour icon in display?
had to go sport and 23 to get moving a bit.
as regards hills want to go up slow but easy
did the same road on vita uno 32f 14 r was somewhat easier
www.velominati.com has a cadence calculator
what is the op I keep seeing in posts
52.79 miles covered I bar left at 50 miles no idea how far that gets me
50 miles, 12.5 miles per segment so 12.5 miles left, roughly.

Use Turbo :rolleyes: if you want to go up hills faster :mad:

oh and yes of course the meter doesn't go all the way up given it's on half power ;)
 

mike killay

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Feb 17, 2011
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I think there is case for throttle only but maybe speed limited to 10mph. With motor geared for this speed it would be great climber under throttle, which is essential for these riders.
Quite often physically challenged people are band from driving, the only option for independence is electric mobility scooters. The ebike gives them option to do some exercise if they want to while travelling quite a bit faster.


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Why limit it to 10mph?
On my Tonaro crank drive I have removed the magnet ring and only use the throttle.
I find it ideal as I can get full power at any time.
I came up behind two people on Bosch drives on a hill outside Kemmel in Belgium. They were pedalling along at about 12 mph.
It was a bit embarrassing because I had to ding my bell to get past them.
I was doing 14mph up the hill, not pedalling at all.
 

Croxden

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Jan 26, 2013
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But I like riding a bike otherwise I would have a moped.
 
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RobF

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Dozens of very authoritative-sounding posts on here from posters who don't ride - or sell - Bosch bikes.

Too much is made of the torque sensor - set to turbo, you aren't doing a lot more than turning the pedals to activate the motor.

The Bosch system gives decent assistance over a fairly wide cadence range, about 40 to 90 rpm.

I struggle to understand some of the OP's posts, but it may be he'd be better off with a bike with a bit more power than is strictly legal available on demand via a throttle or rotation sensor.
 
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Woosh

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I struggle to understand some of the OP's posts, but it may be he'd be better off with a bike with a bit more power than is strictly legal available on demand via a throttle or rotation sensor.
he's already got a Tonsheng / Mxus CD conversion before buying his Bosch. He's after a greater assist ratio to exploit the potential of his Active Line motor.
He only gets about 350W out of a possible 500W output of the motor because he can't spin the cranks at 90rpm. That's OK on flat road, but not good enough on hills.
I wonder how long you can keep spinning at 90rpm.
Some of you can't see the wood for the trees.
You only see me as an interested competitor to Bosch every time I post on a Bosch thread so you dismiss me out of prejudice.
 
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RobF

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There's very little to be gained from a Bosch motor from spinning at 90rpm over and above about 50 or 60.

I cycle by feel, not gadgets, but if I spin at 80rpm or above on my Bosch bike the 'change up' upward arrow appears on the display.

Different Bosch motors do behave a bit differently.

My Riese and Muller has what Bosch describe as 'sports' software which I reckon feeds more power at a lower cadence than the 2012 Classic motor on my previous bike.

Trade off is higher power consumption, and being Bosch it's locked down so there's no way to tinker with it.
 

Woosh

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Trade off is higher power consumption, and being Bosch it's locked down so there's no way to tinker with it.
the OP is not new to e-biking, he probably knows that already. If he could do something simple like changing the cassette or his 18T front ring to get more out of the Bosch bike, he'll do it. As I said before, if he could pedal harder or spin faster on hills, or a software update with eMTB function, his problem is solved.
 

mike killay

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I think that we are now talking at cross purposes.
Originally, ebikes appealed to older, less fit people who needed all the help that they could get yet did not want a motor cycle.
Then came eMTBs and a younger fitter group bought them.
Now we have the situation that older, geriatric, arthritic people like me who have enjoyed cycling in the past want a silent, fume free mode of transport. I need full power on tap, not doled out parsimoniously via some unalterable secret soft ware. That is where the throttle controlled bike comes in. True the riding experience is reminiscent of motor cycling, but as I can only walk about 150 yards and not pedal very hard, a throttle bike answers my needs.
Fitter cyclists like Artstu want to retain the cycling 'feel alike' and are well able to pedal hard and long. So, the Bosch system suits them very well.
Of course, these fit cyclists will one day reach the point at which I already am.
Then their views might change.
 

Kendalian

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I have the Bosch Active Line in my Orbea Katu e20 which I have only done 90 miles on as yet. Can I ask a basic question as to how it works? Does it have a 'torque sensor' to measure how much power I put into the pedals? The reason I ask is that I was out on the bike yesterday 'up hill and down dale' on the hilly roads around here and I was taking note bearing in mind this thread. Up hill in too high a gear (7/8) I was putting lots of pressure on the pedals but the Bosch system only gave me around half power. Changing down to gear 2/3 I was putting less pressure on the pedals, my cadence went up (to around 60 I think - no meter), the motor gave me maximum assist and I went up the hill faster. I haven't yet got my head around how the system operates - I would have expected more assist from the motor in the higher gears than the lower ones as I was working harder - does it also take account of cadence? I also noticed if I pedalled really fast, once I was at a cadence level that the 'change gear' icon came on the assist power dropped from full to 3/4. I love the bike - after 18 miles of 'up and down' I was still as 'fresh as a daisy'! (I'm 61, 80kg and neither fit nor unfit but finding hills hard work on a non-ebike).
Cheers
Kendalian
 
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Crockers

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If you look at the "automatic " systems, they are all based on cadence. When your cadence drops they reduce the gear to increase it so you can maintain the level of assistance you have selected.

I think that answers many questions on how to use a hub motor efficiently.
 

Artstu

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Aug 2, 2009
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Fitter cyclists like Artstu want to retain the cycling 'feel alike' and are well able to pedal hard and long. So, the Bosch system suits them very well.
Of course, these fit cyclists will one day reach the point at which I already am.
Then their views might change.
Whilst I might have better fitness compared to some, I live with a chronic illness that limits my power output, I don't ride an e-bike by choice, it's a necessity.

-------------------------------------------------------------

As to the OP, I agree with Rob that his posts don't make sense. Woosh/Trex is jumping to conclusions based on unreliable information.

This thread is an annoying waste of time, and I'm not going to waste my time further,
 

RobF

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Sep 22, 2012
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I have the Bosch Active Line in my Orbea Katu e20 which I have only done 90 miles on as yet. Can I ask a basic question as to how it works? Does it have a 'torque sensor' to measure how much power I put into the pedals? The reason I ask is that I was out on the bike yesterday 'up hill and down dale' on the hilly roads around here and I was taking note bearing in mind this thread. Up hill in too high a gear (7/8) I was putting lots of pressure on the pedals but the Bosch system only gave me around half power. Changing down to gear 2/3 I was putting less pressure on the pedals, my cadence went up (to around 60 I think - no meter), the motor gave me maximum assist and I went up the hill faster. I haven't yet got my head around how the system operates - I would have expected more assist from the motor in the higher gears than the lower ones as I was working harder - does it also take account of cadence? I also noticed if I pedalled really fast, once I was at a cadence level that the 'change gear' icon came on the assist power dropped from full to 3/4. I love the bike - after 18 miles of 'up and down' I was still as 'fresh as a daisy'! (I'm 61, 80kg and neither fit nor unfit but finding hills hard work on a non-ebike).
Cheers
Kendalian
A Bosch bike has speed, cadence, and torque sensors.

The data from those is fed through software which decides how the power is delivered.

What this means is there is a bit of a knack to getting the most out of the system.

It's something you will soon learn - your post shows that process has already begun.
 
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Dozens of very authoritative-sounding posts on here from posters who don't ride - or sell - Bosch bikes.
Just in case you included me in that group, I was testing a Bosch CX Performance yesterday, in an attempt to understand OP's problem. I've ridden Bosch and other CD bikes on many occasions. Nothing from my tests yesterday changes any of my comments or opions.

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. The decreasing torque is caused by the back emf from the motor as it approaches its max rpm. The back emf cuts down the current to make the limit below what the controller can allow. All BLDC motors behave like that.

For maximum torque from the motor when climbing in any one gear, you need a cadence of about 60. That affects how steep you can climb in that gear. By pedalling harder and faster in that gear, you'll climb faster, but with more effort from yourself. Changing down to a low gear makes pedalling easier and speed less
 
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Kendalian

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Yes - I do know how to ride the bike, I was just curious as to how it was working as I thought it just operated with a torque sensor, hence why I was trying to go up hill in the 'wrong' gear to see what happened. I sussed out how to ride it within 10 miles.

Thanks RobF, that helps make sense of the system. As I said, I love the bike.

Cheers
Kendalian
 
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Artstu

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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.
Not true, I often change up a gear to get more torque from my bike, seems counterintuitive, and down to the way the system is programmed.

ETA. Dipping back into the peak torque rpm, where I'd prefer to be spinning a little bit more.
 
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RobF

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Yes - I do know how to ride the bike, I was just curious as to how it was working as I thought it just operated with a torque sensor, hence why I was trying to go up hill in the 'wrong' gear to see what happened. I sussed out how to ride it within 10 miles.

Thanks RobF, that helps make sense of the system. As I said, I love the bike.

Cheers
Kendalian
I suspect most new Bosch riders have a similar experience, it takes only a very few miles to work out the best technique.

Plenty of hills to play on where you are.
 

Artstu

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Yes - I do know how to ride the bike, I was just curious as to how it was working as I thought it just operated with a torque sensor, hence why I was trying to go up hill in the 'wrong' gear to see what happened. I sussed out how to ride it within 10 miles.
Sorry, I misread your question a little.