Failed on my first big hill

[Deleted member 4366]

In lowest gear my haibike is at most doing 3 mph with a cadence of 60, which equates to cut off point in top.The motor is very very low geared. ( I,d estimate 1000 rpm per 1kmh in lowest gear) Even a two speed hub will be at least double that in lowest ratio,

So you've now become an authority on a two-speed hub motor. When was the last time you tried one? What's that? Never! Even if you had gone as far as to read the specification, you would have realised that what you wrote was more ball-cox. It's right in its range of maximum torque at 3 to 5 mph.

When I calculate the speed of your bike in bottom gear at a cadence of 60, I get approximately 5mph. Do you have a two-speed hub fitted to your back wheel? If not, can you explain the gearing that gets you to 3 mph with a cadence of 60?

 

[(NoLongerRegistered#15675)]

So you've now become an authority on a two-speed hub motor. When was the last time you tried one? What's that? Never! Even if you had gone as far as to read the specification, you would have realised that what you wrote was more ball-cox. It's right in its range of maximum torque at 3 to 5 mph.

When I calculate the speed of your bike in bottom gear at a cadence of 60, I get approximately 5mph. Do you have a two-speed hub fitted to your back wheel? If not, can you explain the gearing that gets you to 3 mph with a cadence of 60?

I had double chain ring fitted to my bike..but principal same for standard one so its irrelevant.
Even if your two speed hub is at its max torque at 3 to 5 mph it still has less torque than cd at wheel at those speeds even of a standard cd ( mtb)
To achieve similar torque AT WHEEL the hub has to draw more current when at 3mph than a CD in its bottom gear. (. Which is where all this started)
Look just agree to differ.
Go out borrow a mtb cd ( doesn't have to have double chain ring, Bosch cant)Put it in lowest gear and pedal it up some 1 in 3 slope....
Then try it with hub..its completely different...
Its not complicated..The, CD when in bottom gear is way lower geared for motor than hub. At times that can be beneficial. That's all I,m saying for goodness sake. Stop making it such an argument.

Are you saying your hub is lower geared than my cd ?( or a standard yam haibike in bottom few gears)
Or are you saying that gearing does not affect torque at back wheel ??

First a strange thing for a cyclist to suggest .
Second a strange one for an engineer.

 

[trex]

xiongda publish the test report for their 36V XD motor here:
http://xiongdamotor.en.alibaba.com/product/1557178214-220560510/New_Invention_2_speed_Ebike_Motor_Amazing_Torque.html

it is an excellent motor for hill climbing, at 80 RPM (highlighted in blue near the bottom of their chart), where the BPM and the Ezee also excel, torque is 42.58NM and efficiency is 63.8%.
Climbing hills with the XD will quickly become inefficient at below this RPM. Torque will increase still but the cost in efficiency will make this counter-productive.

80 RPM on 26" wheels =80/12.9 = 6.2MPH
the motor simulator at ebikes.ca http://www.ebikes.ca/tools/simulator.html gives the BPM about 46NM and 66%, to the Ezee (250rpm) 52NM and 58% efficiency.

Does anyone know the torque and efficiency figures for other motors?

Based on this data, my choice goes to the CX class motors for hill climbing at anything steep enough to bring your speed to below 6mph against those 3.

 

[(NoLongerRegistered#15675)]

xiongda publish the test report for their 36V XD motor here:
http://xiongdamotor.en.alibaba.com/product/1557178214-220560510/New_Invention_2_speed_Ebike_Motor_Amazing_Torque.html

it is an excellent motor for hill climbing, at 80 RPM (highlighted in blue near the bottom of their chart), where the BPM and the Ezee also excel, torque is 42.58NM and efficiency is 63.8%.
Climbing hills with the XD will quickly become inefficient at below this RPM. Torque will increase still but the cost in efficiency will make this counter-productive.

80 RPM on 26" wheels =80/12.9 = 6.2MPH
the motor simulator at ebikes.ca http://www.ebikes.ca/tools/simulator.html gives the BPM about 46NM and 66%, to the Ezee (250rpm) 52NM and 58% efficiency.

Does anyone know the torque and efficiency figures for other motors?

Based on this data, my choice goes to the CX class motors for hill climbing at anything steep enough to bring your speed to below 6mph against those 3.

So the OP needs either a two speed hub motor or a CD mtb ???
.
Perhaps we could all agree on that ?

 

[trex]

Climbing a hill at below 6mph is very tedious. Constantly thinking of gears does not come naturally to most people and nobody wants to know the temperature of the motor. I always believe that choosing a motor on paper data alone is not good, otherwise, everyone would buy a CD bike.
However, data helps to eliminate a number of unsuitable bikes for the job.
If the OP does not like to climb hills slowly, then his choice is very limited. Most of the best suitable bikes are not sold in the shops.

 

[Artstu]

It may well have meant raw food in the context being used. In all languages word combinations are used by the native speakers in odd or slang fashion to give variations of meaning.
.

It was this one, nothing to do with the meaning of Strava and Flud knows so.

My wife did equivalent of Winnats yesterday..its hardly Alp Duez.
Just cant see her ( or perhaps me) being capable of that on hub, certainly not the ones I,ve tried.

Interesting, where's that then? and does it have a Strava segment?

and Whilst Winnats is a short climb compared to Alp d'Heuz it is actually steeper https://www.strava.com/segments/661401

 

[Geebee]

So the OP needs either a two speed hub motor or a CD mtb ???
.
Perhaps we could all agree on that ?

Nope, an Ezee hub should stomp up the op's hill with moderate assist and I assume other larger Hubs would do similar.
A smaller hub would do it with more rider input, this was a style of bike I used to like, you get a moderate work out and your fitness improves.

If you could provide no assist at all it would be a different matter.

 

[trex]

A smaller hub would do it with more rider input.

a lot more than most people would want to - large hubs are powered by 18A-20A controllers, normal sized hubs by 14A-16A controllers. Each Amp is 36W of power. The difference in power when climbing hills between the two classes is about 4A, 140W. Most people can only manage about 100W of user input, 150W when pedaling hard.
The problem, as I see it, is that CD bikes are extremely pleasant and lively to ride on flatish roads (especially when a bit derestricted) where hub bikes can feel a bit wooden, while on undulating roads, CD bikes are constantly demanding and big hubs work like a dream. So if you live in a hilly area and can only have one bike, you will have to make a difficult choice. How hilly does it have to be before big hubs win over CD? I'd say 6%-7%, then CD wins back over big hubs at over 14%.

 

[Deleted member 4366]

Climbing a hill at below 6mph is very tedious. Constantly thinking of gears does not come naturally to most people and nobody wants to know the temperature of the motor. I always believe that choosing a motor on paper data alone is not good, otherwise, everyone would buy a CD bike.
However, data helps to eliminate a number of unsuitable bikes for the job.
If the OP does not like to climb hills slowly, then his choice is very limited. Most of the best suitable bikes are not sold in the shops.

Not on my bike, Trex, but it depends on what you mean by tedious. You just engage a low gear and start pedalling. It's perfectly happy at speeds much lower than 6 mph. The motor is just like a winch. Don't gorget that mine's the 48v version, so that data table doesn't apply to mine.

You get the same effect when you put a hub-motor in a 16" wheel, it'll be happy at 3 mph, just like the one I built for forum member Andy of the South, or when you put an Ezee motor, BPM or equivalent in a 20" wheel.

This argument started when Flud wrote "There is no way a hub motor can compete with a cd unit on limited current on any type of steepclimb", which you must agree is not true. If I pitch my bike against his in any hill-climb, it'll beat it in speed effort and probably efficiency too. It seems that his experience is based on the one bike that he tried with a hub-motor.

 

[(NoLongerRegistered#15675)]

It was this one, nothing to do with the meaning of Strava and Flud knows so.



Interesting, where's that then? and does it have a Strava segment?

and Whilst Winnats is a short climb compared to Alp d'Heuz it is actually steeper https://www.strava.com/segments/661401

Artsu

There are loads of off road climbs as hard as Winnats around Derbyshire??? Don't get your point ?? Asking for Strava was being sarcastic, so I was back.
Try Winn Hill from Yorkshire Bridge...you,ll never find a Strava for it, well not to my knowledge but never look at them anyway.
Any how..
Been to Winnats this morning..see new thread..

 

[(NoLongerRegistered#15675)]

Not on my bike, Trex, but it depends on what you mean by tedious. You just engage a low gear and start pedalling. It's perfectly happy at speeds much lower than 6 mph. The motor is just like a winch. Don't gorget that mine's the 48v version, so that data table doesn't apply to mine.

You get the same effect when you put a hub-motor in a 16" wheel, it'll be happy at 3 mph, just like the one I built for forum member Andy of the South, or when you put an Ezee motor, BPM or equivalent in a 20" wheel.

This argument started when Flud wrote "There is no way a hub motor can compete with a cd unit on limited current on any type of steepclimb", which you must agree is not true. If I pitch my bike against his in any hill-climb, it'll beat it in speed effort and probably efficiency too. It seems that his experience is based on the one bike that he tried with a hub-motor.

Mmmm...on reflection that is rather a sweeping arrogant opinion...apologies..
You are absolutely right, I should have said with respect to the ones I have tried...In my defence I had already taken some stick...
Think other point is I am only ever speaking about mtb, very rarely do I actually go on road..just seems to me ( on bikes I,ve tried) cd is more adaptable to rider, in that it gives its torque at crank and rider decides what he,s doing with it. With Hub all that is taken away...( probably digging deeper here)
I do think mtb is more suited to cd over hub.
But...??? No doubt loads out there are perfectly suited with hub mountain bikes.??
And having said all this, just to stir up folk again, any hub motered bike is going to have to be damned good to improve over how satisfied I am with Haibike...?? Hard act to follow..

 

[Artstu]

Artsu

There are loads of off road climbs as hard as Winnats around Derbyshire??? Don't get your point ?? Asking for Strava was being sarcastic, so I was back.
Try Winn Hill from Yorkshire Bridge...you,ll never find a Strava for it, well not to my knowledge but never look at them anyway.
Any how..
Been to Winnats this morning..see new thread..

It was a perfectly simple question. You said your wife had ridden up a climb the equivalent of Winnats, I simply asked where it was?

Asking about a Strava segment for this climb was in no way sarcastic. I merely wished to see the climb so that I could at some point attempt it myself. There are Strava segments everywhere.

From you last post it appears you're perhaps talking about an unpaved climb?

Not understanding a simple question like that makes me wonder if that big chip on your shoulder is affecting your reasoning.

 

[trex]

...
any hub motered bike is going to have to be damned good to improve over how satisfied I am with Haibike...?? Hard act to follow..

you are not wrong there. The people who oppose you on this thread already have access to a wide selection of e-bikes. Shops don't stock the hub bikes that would give your Haibike a beating.

 

[(NoLongerRegistered#15675)]

Trex
Thanks for comment, just be careful with sectioning my post in quote, a few on here like to jump on stuff taken out of context.

Artsu
Just calm down for goodness sake..
What on earth have I said to get you so wound up...
Come up to Winnats, we,ll have a cycle together and a beer..I have no chip on my shoulder..perhaps a but opinionated about my bike but so what ???
And yes obviously unpaved. Came down past whispering mountain/ caves today where road has collapsed...but so what..
And wife went around Lady Bower and up hill to the right ( behind pub) and back down and all around Howden..way more than going up Winnats ??? What's your point...

 

[Artstu]

Try Winn Hill from Yorkshire Bridge...you,ll never find a Strava for it,

Off-road isn't my thing. Winnats is tarmac, so not comparable as you implied.

Strava segment https://www.strava.com/segments/10037742

and my last reply to you.

 

[(NoLongerRegistered#15675)]

Off-road isn't my thing. Winnats is tarmac, so not comparable as you implied.

Strava segment https://www.strava.com/segments/10037742

and my last reply to you.

You don't want a beer then ?

 

[flecc]

very rarely do I actually go on road.

I wish this had been made clear earlier. Many of us are predominantly road riders, in my case it's nearly all my riding.

Off road, especially on rough stuff, there's a good case for CD on other factors than drive efficiency.
.

 

[(NoLongerRegistered#15675)]

I wish this had been made clear earlier. Many of us are predominantly road riders, in my case it's nearly all my riding.

Off road, especially on rough stuff, there's a good case for CD on other factors than drive efficiency.
.

Yes, unfortunately I,m only now just realising this.
But ahwell, no harm done..
I,ll look for an emtb forum and upset all them..
Take care.

 

[fishingpaul]

Yes, unfortunately I,m only now just realising this.
But ahwell, no harm done..
I,ll look for an emtb forum and upset all them..
Take care.

First of all hi and welcome to the forum flud,i see you have had a baptism of fire,i hope you stay around and contribute some more to the forum,i am sure you are very happy with your bike,and your enthusiasm is admirable,but when you try and argue against flecc and dv8,it is not going to end in your favour,when you have tried all or the majority of the hub motors available,and also tried the bosch Panasonic Yamaha bbs and been given bikes to test,knowing that you will give an honest unbiased reviewer,then you can argue all you want,flecc and dave have helped hundreds if not thousands of people out,not for any gain to themselves but out of a passion for electric bikes,neither sell any bikes as far as I am aware or gain from any sales but have spent many years contributing to this forum,in my experience there are many hub geared bikes that are all pretty much the same,they require a lot of rider assistance up any real hills,but the ezee, bafang bpm and a few others are in a different class,i have an ezee hub off a 2008 torq and I really cannot see anything that would be any better on hills,my chain broke once and it pulled my 16 + stone up a hill on 700c wheels, that other electric bikes that I have owned required a lot of effort just to help the motor out,a hub motor with a throttle also offers the most choice, I can choose a little help no help or loads of help,without selecting different modes.

 

[(NoLongerRegistered#15675)]

First of all hi and welcome to the forum flud,i see you have had a baptism of fire,i hope you stay around and contribute some more to the forum,i am sure you are very happy with your bike,and your enthusiasm is admirable,but when you try and argue against flecc and dv8,it is not going to end in your favour,when you have tried all or the majority of the hub motors available,and also tried the bosch Panasonic Yamaha bbs and been given bikes to test,knowing that you will give an honest unbiased reviewer,then you can argue all you want,flecc and dave have helped hundreds if not thousands of people out,not for any gain to themselves but out of a passion for electric bikes,neither sell any bikes as far as I am aware or gain from any sales but have spent many years contributing to this forum,in my experience there are many hub geared bikes that are all pretty much the same,they require a lot of rider assistance up any real hills,but the ezee, bafang bpm and a few others are in a different class,i have an ezee hub off a 2008 torq and I really cannot see anything that would be any better on hills,my chain broke once and it pulled my 16 + stone up a hill on 700c wheels, that other electric bikes that I have owned required a lot of effort just to help the motor out,a hub motor with a throttle also offers the most choice, I can choose a little help no help or loads of help,without selecting different modes.[/QUOTE

Hi Paul
Thanks for welcome.
Will be contributing again .
On the argument...
Couple of points
Yes I did make a few arrogant comments for which I,ve already apologised.As I said at time a few had been very lets say impassioned ,in their defence of hubs.Unfortunately I responded to dv8 about a comment from Dan,which only aggregated situation. Appoligies again. Only realized after reading back.
However, after reading my own comments again the conclusion I am saying Hubs aren't good climbers is wrong. That has never been my point. Obviously some are, and equally obviously I have not tried them
The crux of my argument, probably poorly made, was the overall ratio ( ie to back wheel) is much much lower for cd mtb units than hub drives.,and that for mtb ( because of scope of being able to alter overall ratio for rider and motor ) has benefits for certain conditions.
Not sure why either of these proved so contentious .
Any how..enough said..
Thanks for welcome.
Going out on bike...
Take care.