kalkhoff battery and gearing problems,

tiredlegs

Finding my (electric) wheels
May 13, 2010
11
0
Hello, I have a gearing problem. My partner ordered a kalkhoff agattu stepthru from 50cycles, she asked for a 19 tooth rear sprocket but they only had an 18 tooth, so she said yes to it. Since getting the bike she sais her bike is slower by ten minutes compared to her synergie mistral, and it is no good on hills or against wind, Any advise on suitable front/rear gearing giving good/reasonable speed and hill climbing ability. At the moment she hates the agattu because it is so much slower than the mistral which she was hoping it would come near to matching. The bike also has an underlying pulsing surge. on the Plus side it freewheels beautifully. Also when my partner phoned 50cycles about new battery conditioning she was told that the first charge conditioned it, and that was it, no discharging mentioned over the phone or in the manual. Do the batteries no longer need a conditioning charge?. Thanks
 

badpoet

Pedelecer
May 20, 2010
32
0
The emotion manual recommends two full discharges on the same panasonic system - don't know if that helps:)
 

HarryB

Esteemed Pedelecer
Jan 22, 2007
1,317
3
London
Agreed with Badpoet that you do have to do the two conditioning discharges but it won't help solve the underlying problem. Have you explained the importance of cadence? The lower the cadence the more power you get and provided you don't encounter too many hills the 18 tooth sprocket should help this. The other way of dealing with this is to go for an 11 tooth conversion as this allows you to raise the cadence by 20% or so. You would have to lower the gearing as the 18 and 11 combination is a bit too much. It should be possible to get similar journey times to the mistral and I say possibly even quicker if you know how to ride the Panasonics.
 
Last edited:

flecc

Member
Oct 25, 2006
52,822
30,382
The pulsing surge that you refer to is the way this system works, it adds to the leg power on each pedal stroke so is very different from a hub motor system like the Mistral's

As Harry says, try to get used to the system and think of it as riding a normal bike but having magically stronger leg muscles. Keeping the pedal rotation speed lowish will give the most power as said. The other thing to note is that the motor input is in relation to the rider's input. If the rider input is low, the motor help will be low as well, regardless of what power mode is selected.
.
 

lemmy

Esteemed Pedelecer
As Flecc says, she needs to get used to the system.

The hill climbing ability is possibly the best available but like changing from a petrol to a diesel engine, you need to know how to use it best.

If you have a gps or cycle computer on the bike, note that in top gear maximum power assistance comes at just under ten mph. Pedalling faster than this reduces the power. The surging you notice is more in the mind than in practice. Most people who've ridden my Tasman for the first time remark on how smooth the power delivery is.

As Flecc puts it, the hub motor is a moped - a powered vehicle with pedals. The Panasonic system is a bicycle with power assistance. It.'s not the same thing and means that a lot of the time the motor will be turned off and the Kalkhoff ridden as a normal bicycle.

Get her to persevere - some people are more adaptable than others - but in the end she'll really like it. Personally, I find no need to change the gearing, after toying with the idea, but even if I did, I wouldn't consider an 18t.
 

tangent

Esteemed Pedelecer
Mar 7, 2010
299
0
I have a 12T motor sprocket and 18T hub sprocket on a 7 speed hub. The 18T hub sprocket I have is equivalent to a 19T on the 8 speed hub.

The 12T/18T/7 spd combination means that I can do 25mph on the flat and still have power assistance. Most of the time though I cruise along between 18 and 20mph in 6th gear, or drop down to 16-18mph in 5th if there is a head wind or I am feeling lazy, tired or hot. My normal commute does not have steep hills, but on other journeys I have made I have found that I can get up hills of up to 12%, in 3rd or 4th gear with not much effort. I like to go fast, but having a 18T on a 8 speed hub would seem over the top to me.

Fitting a 11T or 12T motor sprocket transforms the bike, allowing power assistance to still be available at much more normal cadences and I would recommend this first before changing the hub sprocket. After this, if you are not really interested in pedalling at high speeds, then I would recommend that you work out what gear you are most comfortable in for top gear and use this to choose a suitable hub sprocket. A larger hub sprocket will make pedalling at high speeds more difficult, but will reduce the gaps between the gears.

The gear ratios of the 8 speed hub with various sprockets is as follows:

HTML:
          18T  19T  20T  21T  22T  23T
1 0.527  33.6 31.8 30.2 28.8 27.5 26.3
2 0.644  41.1 38.9 37.0 35.2 33.6 32.1
3 0.748  47.7 45.2 42.9 40.9 39.0 37.3
4 0.851  54.3 51.4 48.8 46.5 44.4 42.5
5 1.000  63.8 60.4 57.4 54.7 52.2 49.9
6 1.223  78.0 73.9 70.2 66.9 63.8 61.0
7 1.419  90.5 85.7 81.5 77.6 74.0 70.8
8 1.617 103.1 97.7 92.8 88.4 84.4 80.7
So at the moment, gear 8 is giving you 103.1 gear inches. If you are completely comfortable with gear 6 as your top gear (78.0 in the above table) then a 23T sprocket would make gear 8 similar to your current gear 6. Similarly if you would like gear 7 to be top gear (90.5) then a 21T would provide something similar (88.4) in gear 8.
 

tiredlegs

Finding my (electric) wheels
May 13, 2010
11
0
thanks for help & advise, aggatu gear battery probs.

thanks fellas,
would you believe it, my partner carole is happier with the bike today. She is now getting used to the differenent way power is delivered between the Mistral and Agattu. She used to ride the mistral flat out at times at a fairly high cadence, despite a hip problem. I have now ordered an eleven tooth motor sprocket, and will try it with original rear sprocket 21/22 tooth i think, and see if that suits her better.
I had a look on e-motion site, and yes, they do say condition the battery by running down twice, so i will follow that advice to maximise battery life. I noticed the same advice elsewhere, and on pedelec.
Pity there was not a higher ah battery available like a 14ah for greater range, though it might not fit the frame.
 

flecc

Member
Oct 25, 2006
52,822
30,382
There is a 15 Ah battery now, but it's much wider and needs revised cranks, cowlings and battery platform. Since it's then not interchangeable with the 10 Ah and the cost of the large one is very high, it's unlikely to be popular.

Since the 10Ah is only just over 2 kilos, I think the best solution for longer range is to carry a second one, and that method has more flexibility in how the batteries can be used.
.
 

Grizzly Bear

Esteemed Pedelecer
Sep 14, 2007
282
0
65
Swansea
www.grizzlyfish.com
I would just like to point out the fact that, the Mistral is such an user friendly bike, that feels so natural to ride out of the box. It's a great introduction to ebiking, for a fraction of the cost of so called superior machines.
 

Tex

Esteemed Pedelecer
Jun 14, 2009
251
0
Sydney, Australia
I have a 12T motor sprocket and 18T hub sprocket on a 7 speed hub. The 18T hub sprocket I have is equivalent to a 19T on the 8 speed hub.

The 12T/18T/7 spd combination means that I can do 25mph on the flat and still have power assistance. Most of the time though I cruise along between 18 and 20mph in 6th gear, or drop down to 16-18mph in 5th if there is a head wind or I am feeling lazy, tired or hot. My normal commute does not have steep hills, but on other journeys I have made I have found that I can get up hills of up to 12%, in 3rd or 4th gear with not much effort. I like to go fast, but having a 18T on a 8 speed hub would seem over the top to me.

Fitting a 11T or 12T motor sprocket transforms the bike, allowing power assistance to still be available at much more normal cadences and I would recommend this first before changing the hub sprocket. After this, if you are not really interested in pedalling at high speeds, then I would recommend that you work out what gear you are most comfortable in for top gear and use this to choose a suitable hub sprocket. A larger hub sprocket will make pedalling at high speeds more difficult, but will reduce the gaps between the gears.

The gear ratios of the 8 speed hub with various sprockets is as follows:

HTML:
          18T  19T  20T  21T  22T  23T
1 0.527  33.6 31.8 30.2 28.8 27.5 26.3
2 0.644  41.1 38.9 37.0 35.2 33.6 32.1
3 0.748  47.7 45.2 42.9 40.9 39.0 37.3
4 0.851  54.3 51.4 48.8 46.5 44.4 42.5
5 1.000  63.8 60.4 57.4 54.7 52.2 49.9
6 1.223  78.0 73.9 70.2 66.9 63.8 61.0
7 1.419  90.5 85.7 81.5 77.6 74.0 70.8
8 1.617 103.1 97.7 92.8 88.4 84.4 80.7
So at the moment, gear 8 is giving you 103.1 gear inches. If you are completely comfortable with gear 6 as your top gear (78.0 in the above table) then a 23T sprocket would make gear 8 similar to your current gear 6. Similarly if you would like gear 7 to be top gear (90.5) then a 21T would provide something similar (88.4) in gear 8.
tangent: facinating reply. Two questions: 1) how is your range effected? 2) I'd never heard of a 12 tooth motor sprocket/ where did you get that?
 

tangent

Esteemed Pedelecer
Mar 7, 2010
299
0
tangent: facinating reply. Two questions: 1) how is your range effected? 2) I'd never heard of a 12 tooth motor sprocket/ where did you get that?
As Flecc says, check out the previous article. I would stick with the 11T as you have ordered it now. The difference between this and the more expensive and unofficial 12T is hardly noticeable. The 11T is much better than the 9 though.

As for range, I cannot really tell as I usually only do 15 miles per day. At the weekend I did 20 miles before recharging, including some fairly steep hills, but still had 3 LEDs showing on the battery.
 

carpetbagger

Esteemed Pedelecer
Nov 20, 2007
744
18
blackburn
this is a route with an 11t which i do and it starts flashing on the handlebars at half a mile from the end usually,i think its about 1 or 2 on the battery. if you look at the elevation its is not flat.... !
Gmaps Pedometer
 

tiredlegs

Finding my (electric) wheels
May 13, 2010
11
0
excellent mistral

I would just like to point out the fact that, the Mistral is such an user friendly bike, that feels so natural to ride out of the box. It's a great introduction to ebiking, for a fraction of the cost of so called superior machines.
Have to agree with you on that one, faster than my wisper 905se, but very much more agricultural. The bike has been ridden pretty much flat out everywhere. The battery has done two solid years and still going strong, maybe because it has been kept topped at all times topped up. thumbs up for the bike.
 

Grizzly Bear

Esteemed Pedelecer
Sep 14, 2007
282
0
65
Swansea
www.grizzlyfish.com
Have to agree with you on that one, faster than my wisper 905se, but very much more agricultural. The bike has been ridden pretty much flat out everywhere. The battery has done two solid years and still going strong, maybe because it has been kept topped at all times topped up. thumbs up for the bike.
The Mistral my wife had is now 4 years old, a friend bought it off us, and I replaced the battery with a Ping LIFEPO4. With the Ping it now does 40 miles on a charge(30 miles previously), it's been super reliable too, literally nothing has gone wrong with it, except the battery wore out after 2 1/2 years, which is not bad really.
 

oriteroom

Esteemed Pedelecer
Jul 13, 2008
297
110
The gear ratios of the 8 speed hub with various sprockets is as follows:

HTML:
          18T  19T  20T  21T  22T  23T
1 0.527  33.6 31.8 30.2 28.8 27.5 26.3
2 0.644  41.1 38.9 37.0 35.2 33.6 32.1
3 0.748  47.7 45.2 42.9 40.9 39.0 37.3
4 0.851  54.3 51.4 48.8 46.5 44.4 42.5
5 1.000  63.8 60.4 57.4 54.7 52.2 49.9
6 1.223  78.0 73.9 70.2 66.9 63.8 61.0
7 1.419  90.5 85.7 81.5 77.6 74.0 70.8
8 1.617 103.1 97.7 92.8 88.4 84.4 80.7
So at the moment, gear 8 is giving you 103.1 gear inches. If you are completely comfortable with gear 6 as your top gear (78.0 in the above table) then a 23T sprocket would make gear 8 similar to your current gear 6.
Thanks for a useful table - just changed from a 23T to 19T on my Pro Connect but kept 9T motor sprocket. Changing Mrs 'O' to a 22T/11T combination, she's less of a speed merchant! Can you explain what 'gear inches' are? Never quite understood the term but can see the effects?

Mike
 

tangent

Esteemed Pedelecer
Mar 7, 2010
299
0
Thanks for a useful table - just changed from a 23T to 19T on my Pro Connect but kept 9T motor sprocket. Changing Mrs 'O' to a 22T/11T combination, she's less of a speed merchant! Can you explain what 'gear inches' are? Never quite understood the term but can see the effects?

Mike
Gear inches are used to compare gear ratios. A gear inch of 60 just means that it is like riding an old penny farthing with a 60 inch wheel. Penny farthings had no gears, instead they had the crank connected to the centre of a large wheel. The bigger the wheel the harder it was to pedal, but a greater speed could be obtained.

My table was knocked together quickly based on a wheel size of 28". However, I think this is probably inaccurate. I suspect that a 700c wheel and tyre is closer to 27". The table is just for comparing the effects of different hub sprockets. The numbers will be different for different wheel/tyre sizes. A non-standard chain wheel would also change the numbers. I will check my tyre size tomorrow and try to come up with a more accurate table, along with a table for a 7 speed hub.
 

JamesC

Esteemed Pedelecer
Sep 1, 2007
435
5
Peterborough, UK
I suspect that a 700c wheel and tyre is closer to 27".
The 700c wheel, fitted with 700 x 38 Marathon Plus tyres, is quite a popular combination amongst forum members.

An excellent start point with this setup when calibrating a mileometer is to use a circumference of 219 cms - it is the right setting for the Mavic A319 rim + 700 x 38 MP's.

This works back to a rolling diameter of 27.44 inches.

James
 

tangent

Esteemed Pedelecer
Mar 7, 2010
299
0
Ok, MP 27.44" wheels then, with a 41T chainwheel. I have added numbers for more extreme 16T an 17T sprockets. Here is the table for the 8 speed hub:

HTML:
          16T   17T   18T  19T  20T  21T  22T  23T
1 0.527  37.1  34.9  32.9 31.2 29.6 28.2 26.9 25.8
2 0.644  45.3  42.6  40.3 38.1 36.2 34.5 32.9 31.5
3 0.748  52.6  49.5  46.8 44.3 42.1 40.1 38.3 36.6
4 0.851  59.8  56.3  53.2 50.4 47.9 45.6 43.5 41.6
5 1.000  70.3  66.2  62.5 59.2 56.3 53.6 51.1 48.9
6 1.223  86.0  80.9  76.4 72.4 68.8 65.5 62.5 59.8
7 1.419  99.8  93.9  88.7 84.0 79.8 76.0 72.6 69.4
8 1.617 113.7 107.0 101.1 95.7 91.0 86.6 82.7 79.1
And here is the table for the unfortunates amongst us with the 7 speed hub:

HTML:
          16T   17T  18T  19T  20T  21T  22T  23T
1 0.632  44.4  41.8 39.5 37.4 35.6 33.9 32.3 30.9
2 0.741  52.1  49.0 46.3 43.9 41.7 39.7 37.9 36.2
3 0.843  59.3  55.8 52.7 49.9 47.4 45.2 43.1 41.2
4 0.989  69.5  65.5 61.8 58.6 55.6 53.0 50.6 48.4
5 1.145  80.5  75.8 71.6 67.8 64.4 61.3 58.6 56.0
6 1.335  93.9  88.3 83.4 79.0 75.1 71.5 68.3 65.3
7 1.545 108.6 102.2 96.6 91.5 86.9 82.8 79.0 75.6
 

SuperPad

Finding my (electric) wheels
Jun 14, 2010
6
0
Dublin
How's it going?

Thanks for a useful table - just changed from a 23T to 19T on my Pro Connect but kept 9T motor sprocket. Changing Mrs 'O' to a 22T/11T combination, she's less of a speed merchant! Can you explain what 'gear inches' are? Never quite understood the term but can see the effects?

Mike
In terms of performance or general "feel", how have you found the sprocket combination of 19T rear with standard 9T motor? Or what's the "before" and "after" like? I'm considering my options...;)