Apologies if the question has already done the rounds.. Should I bother investing in a bigger battery (e'g KTM Bosch or Panasonic hub) for a 6 mile round trip hilly commute? I'm sure this is another obvious question (and forgive me as I'm a non-scientific luddite), but does size equate to oomph as well as stamina? .....ooh er missus
Does size really matter?
- Thread starter musicbooks
- Start date
yes, but you may not have the choice. The Panasonic hub motor comes with its special battery, you can't change that, the Bosch 400WH is the biggest they sell, still not very big.
Bigger batteries can support bigger demand, better at hill climbing and require fewer charging cycles, ultimately result in less pence per mile.
If you have hills, beware that European bikes don't have throttle, you have to input a sizeable effort to pedal uphill. Typically, their assist levels are:
eco: 50%
tour: 110%
sport: 170%
turbo: 250%
That may seem adequate but if you have 10% hills, it's not.
Chinese bikes tend to have much higher assist, like 900%. If you're a bit unfit, get a bike with throttle.
Bigger batteries can support bigger demand, better at hill climbing and require fewer charging cycles, ultimately result in less pence per mile.
If you have hills, beware that European bikes don't have throttle, you have to input a sizeable effort to pedal uphill. Typically, their assist levels are:
eco: 50%
tour: 110%
sport: 170%
turbo: 250%
That may seem adequate but if you have 10% hills, it's not.
Chinese bikes tend to have much higher assist, like 900%. If you're a bit unfit, get a bike with throttle.
Trex....I really must get used to ignoring your postings but sometimes you come out with such garbage it is hard not to respond.
A THROTTLE MAKES ABSOLUTELY NO DIFFERENCE TO THE MAXIMUM OUTPUT OF ANY ELECTRIC BIKE>
The throttle is purely another means of tapping into the power available,if you have a speed sensor bike and set it on PAS level 5 and turn the pedals you will get maximum power,if you then operate the throttle the bike will offer no more power than the max available-you dont need to be an engineer,commonsense tells you that!!!!!
If the throttle is wired in such a way as to always deliver max power and you set the display on a lower PAS setting then the throttle will give more power but only to PAS level 5.
The only advantage of a throttle is that you can tap into the power without turning the pedals,allowing you to use the bike as a mini moped,being lazy if you like!!!
And your final quote 'if you are unfit get a throttle',surely if you are not fit the last thing you want is a throttle,that is a sure way of staying unfit and reducing the range of the bike drastically.
European bikes with speed sensors(note not torque sensors)deliver full power provided that you set it on the max pas setting,whatever that control may be,could be eco-turbo or 1-5,its the same effect.
All my bikes are Chinese,none of them could ever experience a 900 per cent lift when operating the throttle....9 times....that would suggest that the PAS setting was only delivering 10% of the available power,ridiculous!!
I have ridden many German electric bikes from Scott,Cannondale,KTM,Kalkhoff.....they are all well built bikes,that is why they cost £2k upwards,there is no way that a Woosh chinese bike will deliver 3.6 times(900 divided by 250) more power than say a KTM-Panasonic hub bike just because the Woosh has a throttle.
WHAT WORRIES ME IS THAT YOU SAY THESE THINGS WITH SO MUCH CONVICTION THAT PEOPLE MAY ACTUALLY START TO BELIEVE YOU.
KudosDave
A THROTTLE MAKES ABSOLUTELY NO DIFFERENCE TO THE MAXIMUM OUTPUT OF ANY ELECTRIC BIKE>
The throttle is purely another means of tapping into the power available,if you have a speed sensor bike and set it on PAS level 5 and turn the pedals you will get maximum power,if you then operate the throttle the bike will offer no more power than the max available-you dont need to be an engineer,commonsense tells you that!!!!!
If the throttle is wired in such a way as to always deliver max power and you set the display on a lower PAS setting then the throttle will give more power but only to PAS level 5.
The only advantage of a throttle is that you can tap into the power without turning the pedals,allowing you to use the bike as a mini moped,being lazy if you like!!!
And your final quote 'if you are unfit get a throttle',surely if you are not fit the last thing you want is a throttle,that is a sure way of staying unfit and reducing the range of the bike drastically.
European bikes with speed sensors(note not torque sensors)deliver full power provided that you set it on the max pas setting,whatever that control may be,could be eco-turbo or 1-5,its the same effect.
All my bikes are Chinese,none of them could ever experience a 900 per cent lift when operating the throttle....9 times....that would suggest that the PAS setting was only delivering 10% of the available power,ridiculous!!
I have ridden many German electric bikes from Scott,Cannondale,KTM,Kalkhoff.....they are all well built bikes,that is why they cost £2k upwards,there is no way that a Woosh chinese bike will deliver 3.6 times(900 divided by 250) more power than say a KTM-Panasonic hub bike just because the Woosh has a throttle.
WHAT WORRIES ME IS THAT YOU SAY THESE THINGS WITH SO MUCH CONVICTION THAT PEOPLE MAY ACTUALLY START TO BELIEVE YOU.
KudosDave
In bigger did you mean Volts? The Panasonic 47V system does seem to have far more oomph over a 36V system, the KTM e Cross P flies up hills and is extremely quick of the mark when leaving lights etc. 6 miles though isn't very far so a bigger amp battery isn't really necessary for your commute. I'd recommend you try a range of bikes, Ive got the Kudos range and the 'key' KTM bikes in stock and for demo here, not sure if I'm to far for you though?
Musicbooks,to answer your question battery size only makes a difference to performance when the battery is starting to loose its power. For a 6 mile commute a 10Ah battery should make no difference to the performance.
However,the type of battery does make a difference as you get towards the end of the range. The LifePo4 batteries that are fitted to the Kudos Urban series,have almost a straight line voltage curve,the voltage drops off suddenly when the battery is within 1 mile of exhaustion...this means in practice that the battery will perform at almost 100% for 95% of its capacity.
However,the LiMno4 battery as used in our performance series (lighter) will start to reduce the power at about 75% of the range,but the power is reduced gradually,this applies to Lithium Ion or Lithium Polymer type batteries.
But 6 mile the battery should be delivering 100% of its power.
Hope that helps
KudosDave
C
Cyclezee
Guest
Nobody can ignore your posts Dave, they're sooooo long
WHAT WORRIES ME IS THAT YOU SAY THESE THINGS WITH SO MUCH CONVICTION THAT PEOPLE MAY ACTUALLY START TO BELIEVE YOU TOO.
dave, the assist ratios given by Bosch is the multiplication factor.
Motor output = assist ratio * cyclist input
If the ratio is 900%, the motor will supply 90%, the cyclist supplies 10%.
If the ratio is 250%, the motor will supply (250 * 100 /(250+100) % =) 71.42% the cyclist 28.58%
28.58% OK on flat roads, but not on hills if you are unfit.
I posted on another thread a simple calculation of the cyclist's own input.
Read it, you may find that a little maths can go a long way.
http://www.pedelecs.co.uk/forum/threads/which-bike-to-go-for.18502/#post-228958
the power output of the motor of course matters, but so is the demand on the cyclist.
There is no point to buy an e-bike and suffer from it. If you are a bit unfit, you need the backup of a throtttle to rest your legs.
Motor output = assist ratio * cyclist input
If the ratio is 900%, the motor will supply 90%, the cyclist supplies 10%.
If the ratio is 250%, the motor will supply (250 * 100 /(250+100) % =) 71.42% the cyclist 28.58%
28.58% OK on flat roads, but not on hills if you are unfit.
I posted on another thread a simple calculation of the cyclist's own input.
Read it, you may find that a little maths can go a long way.
http://www.pedelecs.co.uk/forum/threads/which-bike-to-go-for.18502/#post-228958
the power output of the motor of course matters, but so is the demand on the cyclist.
There is no point to buy an e-bike and suffer from it. If you are a bit unfit, you need the backup of a throtttle to rest your legs.
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Can someone explain the 900% assist level?
Are there ebike retailers claiming this level of assistance?
Why would anyone buy a less powerful and more expensive "non chinese" bike?
No. With European made bikes, the harder you pedal, the faster you climb.So to cut a long story short
There is a fixed ratio between the motor support and your own input.
On Chinese bikes, it's more complicated but requires much less if no cyclist input. You need to use the e-bike emulator at ebike.ca to work out case by case. The Ezee and BPM motors are widely used for hills, the TCM is a crank drive used mainly by Woosh, smaller than Ezee and BPM, less grunt but has higher efficiency at low speed (below 8 mph). Higher voltage simply makes the motor spin faster.
In the case of the Panasonic hub, voltage is only one parameter, its power comes from the controller, capable of delivering up to 47V * 20A * motor efficiency, most Ezee and BPM run at 36V and 20A * motor efficiency but you can't get 47V * 20A * motor efficiency with the Panasonic hub unless you input 0.28 * 47V * 20A * motor efficiency. That's why I said if you are a bit unfit, you'd be better off with a Chinese Ezee or BPM.
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the 900% assist ratio that I gave earlier is to keep to the Bosch way of specifying assist ratio.
That means the motor will give 900% of the cyclist input.
When you read the European bikes' brochure, you see specified 'Turbo: 250%' that means the motor output is 250% * the cyclist input
Usually, assist ratios are not specified with Chinese bikes, only assist levels, 3 for cheap bikes, 5 for more expensive bikes. Also, most of them do not have torque sensor, the cyclist input cannot be measured accurately, only estimated, so the 900% is my estimate.
People buy expensive bikes because they are designed, not assembled from a menu of components like most Chinese bikes are (with the exception of a few premium brands like Ezee, Momentum), better built and usually have premium components like hydraulic shocks, hydraulic brakes, good rack, good grips, good propstands etc.
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I understand "assist ratios" - Bosch, Panasonic,Kalkhof - all use them.
I presume the chinese "assist levels" are a sort of rough guide, so the figure of 900% is your own personal "estimate", not any industry guideline?
This Kalkoff I've just bought will go up the 17.5% hill up to my house in third gear faster and with about the same amount of effort or less than the Woosh in first.
It is ridiculously undergeared though and if it's the same gearing as a member here who posted his, third is 37." While the Woosh is 34" in first if I remember right.
It is ridiculously undergeared though and if it's the same gearing as a member here who posted his, third is 37." While the Woosh is 34" in first if I remember right.
So, Whoosh bikes are not claiming a 900% assist (ratio) level of assistance with some of their bikes, this is your own claim?
That's my own estimate. Most Chinese bikes do not have torque sensor, the amount of motor power you get depends on the assist level you set, the speed you are travelling at (faster = slightly less power) and the rotational speed of the cranks (faster = slightly more power). The throttle is much more proportional, like a motobike.
D
Deleted member 4366
Guest
You can get bikes that give 1,000,000% assistance. It, s absolutely meaningless if you have a bike with a throttle or pedal speed sensor because you can get all the power from the motor without putting any effort in if you want.
To judge a motor's power, you need to look for the current that the controller is set to and the battery voltage. Multiply to the two together to get a number to compare. Generally, the bigger the motor, the more torque it can give, which is what you need to climb hills.
I was about to type out a reply about the 900% rubbish when I spotted your post? trex needs to slow down with his posts when replying to people asking simple questions.
On my wife's Woosh with me riding it, the assist is nowhere near 900%. On the same bike with her riding it a measly 900% would not move the bike.
point taken, to both of you. While it's easy to explain the proportionality of the Bosch assist ratios, how do you compare with Chinese bikes where these ratios don't exist? I wrote in my first reply 'Chinese bikes tend to have much higher assist, like 900%. If you're a bit unfit, get a bike with throttle'.
Blame kudosdave who immediately picked up on the word 900% but quoted me out of context by omitting the word 'like' before the '900%', that subsequently changed the flow of the thread.
Blame kudosdave who immediately picked up on the word 900% but quoted me out of context by omitting the word 'like' before the '900%', that subsequently changed the flow of the thread.
The best way to describe my wife's Woosh or my 2 Kudos bikes to a new ebiker, would be to say, the bike gives its full power no matter how hard or softly you turn the pedals. However, none of this answers the OP's question.
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