Problem with finding battery/kit to fit small frame 14". Need some help :(

Rileyy

Pedelecer
Feb 8, 2021
27
6
Manchester
Hi!
I'm looking to buy some conversion kit for my bike I'm not sure what to choose and how much will I have to spend(My budget is 500, max £550)
I don't have to go too fast, but need to do 11 miles twice a day to work.

Another problem is my frame is small and I'm afraid I won't be able to mount the battery to it.
One of the sellers responded to my email that I have to change the whole bike and sent ma link to buy a frame for £1499.
So yeah... Not cool.

The bike I have:

The frame (S)

1612824666590.png



I really need help, I have no idea how to solve this issue and I can't afford to change the whole bike :/
My budget is 500, max £550.


I would appreciate any help!
Thank You, Riley
 
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Benjahmin

Esteemed Pedelecer
Nov 10, 2014
2,034
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West Wales
Have a look at geared rear hubs (250w) and a rear rack battery. The weight distribution will be rear biased but, on tarmac, should be able to get used to it.
Alternatively you could go for a front hub and rear rack - works well for me. Make sure that the forks have a strong enough drop out that's capable of taking the strain - fit a torque bracket.
Kits are inshort supply at the mo, what with covid and brexit tantrums.
Don't be tempted by cheap e-bay kits. Most are direct drive motors, power hungry and inefficient (though could possibly suit Linconshire riding) and the batteries that come with them are underspecced and made out of cheap cells.
 
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vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,950
Basildon
In principle, if it's a rigid frame, you can fit a rear motor kit with a rack battery.

For more detailed advice, we need to see a photo of your bike and you must give details of the type of gears on your bike and how many speeds they have
 

FJC71

Pedelecer
Mar 1, 2020
36
12
Hi,

I have been through this with a 14 inch frame, in short there is no good answer for the frame battery issue. I came up with three solutions.

1. The rack battery solution is the most conventional but on a small frame seat clearance can be an issue. The saddle can foul the rack and dimensional information seems to be difficult to come by. This arrangement might not be the best looking on a small frame.

2. Soft pack battery in a frame bag, this gives better weight distribution and is more compact than a hard case so can work. If your going off road this is probably the better option. However its probably going to have to be sourced separately from the rest of the kit.

3. Fix a normal frame battery onto a normal rear rack, this can look odd but it might get round any issues with fouling the seat. Ive seen pictures of this done and it can look a bit odd.

I went for the soft pack solution in the end, no one could convince me or was even willing to provide any information on the dimensions of the rack, I was not wanting to gamble on it not fitting.
 

Rileyy

Pedelecer
Feb 8, 2021
27
6
Manchester
Thank You everyone for the replies!
Maybe I can do this! I was actally considering selling my bike and buying a new electric one, which means I would loose a lot :(

Have a look at geared rear hubs (250w) and a rear rack battery. The weight distribution will be rear biased but, on tarmac, should be able to get used to it.
Alternatively you could go for a front hub and rear rack - works well for me. Make sure that the forks have a strong enough drop out that's capable of taking the strain - fit a torque bracket.
Kits are inshort supply at the mo, what with covid and brexit tantrums.
Don't be tempted by cheap e-bay kits. Most are direct drive motors, power hungry and inefficient (though could possibly suit Linconshire riding) and the batteries that come with them are underspecced and made out of cheap cells.
One of the guys from a shop in town told me I can't mount a rack on my frame, so I think this is not possible :(

In principle, if it's a rigid frame, you can fit a rear motor kit with a rack battery.

For more detailed advice, we need to see a photo of your bike and you must give details of the type of gears on your bike and how many speeds they have
There's 8 speeds - Shimano Altus
So that's how the bike look like:
40691


Hi,

I have been through this with a 14 inch frame, in short there is no good answer for the frame battery issue. I came up with three solutions.

1. The rack battery solution is the most conventional but on a small frame seat clearance can be an issue. The saddle can foul the rack and dimensional information seems to be difficult to come by. This arrangement might not be the best looking on a small frame.

2. Soft pack battery in a frame bag, this gives better weight distribution and is more compact than a hard case so can work. If your going off road this is probably the better option. However its probably going to have to be sourced separately from the rest of the kit.

3. Fix a normal frame battery onto a normal rear rack, this can look odd but it might get round any issues with fouling the seat. Ive seen pictures of this done and it can look a bit odd.

I went for the soft pack solution in the end, no one could convince me or was even willing to provide any information on the dimensions of the rack, I was not wanting to gamble on it not fitting.
1. As far as I'm aware I can't mount rack on this frame (at least that's what they told me in one of the stores in Manchester.
2. That sounds good, do you mount in the frame triangle? Do You have any links for something like that?
3.Again, I don't think I can get a rack for that frame :(


You can fit a small frog battery either to the seat tube or like this:



https://wooshbikes.co.uk/?batteries#smallfrog
Thanks, the frog battery seems like a great solution, but with a budget of 550 for everything I can't spent 299 on battery, but thanks :)
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
16,938
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West Sx RH
A bottle battery or a Hailong 2 side off battery may fit in the triangle, obviously measuring is critical. A tringle mount will be far better then a rack mount.

H2 battery you need 365 x 106 height to be able to fit in the tri area.
Hailong2 Battery 36V12.8AH Panasonic NCR18650-BD Li-ion Battery Pack [Hailong2 battery 36V12.8AH] - $195.00 : Zen Cart!, The Art of E-commerce (topbikekit.com)

Would a bottle battery like this fit ?
G30 Battery 36V9.6AH 18650 Panasonic NCR18650BD Li-ion Battery Pack for Ebike [G30 36V9.6AH bottle battery case] - $149.00 : Zen Cart!, The Art of E-commerce (topbikekit.com)
 
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vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,950
Basildon
You can fit a rack to any bike. I've even made my own, which doesn't take long using aluminium tube from Wickes.

One of these batteries would probably fit. The 7Ah one would take you at least 25 miles as you're not very big.

You'll probably have to increase the size of your chainring, as the one you have looks a bit small for an electric bike.


When you buy a battery like that, you typically have to pay about £30 duty, though I've bought 2 of them and din't have to pay anything on either of them.
 
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FJC71

Pedelecer
Mar 1, 2020
36
12
2. That sounds good, do you mount in the frame triangle? Do You have any links for something like that?
In the triangle, not a recommendation but you will get the idea from this link. https://enerprof.de/en/ebike-batteries/softpacks-in-bags/36v-10s-batteries/111/softpack-battery-36v-10.20ah-20.40ah-35e-in-enerpower-frame-bag?c=100
The dimensions of the bag are given in the photos. A bag like this will take quite a big battery much bigger than you need.
An alternative bag, Roswheel Attack Frame Bag
You need to carefully check the internal and external dimensions for both the space in the frame and in the bag to be sure.
3.Again, I don't think I can get a rack for that frame.
Its not impossible but its very expensive by using a Tobus rack and additional fittings. You would need to check disc clearance as well as all other dimensions to be sure before you commit.
This rack fits through the axle rather than the frame. You would also need one of these.
or one of these.
You will probably also need longer rack stays as well. You might find other rack manufacturers do similar stuff but it will still add a bit of expense. The frame bag is by far the cheapest solution if cost is an issue.

There is a downside to the frame bag in that there is no lock so you must remove the battery if leaving the bike unattended.

I looked at the pics of your bike and noticed that it had a small chainset. This could be an issue if you plan to install a mid drive. The larger chain wheel and housing these typically have might foul the frame. You will need to get detailed dimensions for any mid motor you intend to fit to check this out. In such a case that a mid motor wont fit, a geared rear hub motor is the best option.
 
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Pedaluma

Pedelecer
Sep 28, 2020
30
6
Hi!
I'm looking to buy some conversion kit for my bike I'm not sure what to choose and how much will I have to spend(My budget is 500, max £550)
I don't have to go too fast, but need to do 11 miles twice a day to work.

Another problem is my frame is small and I'm afraid I won't be able to mount the battery to it.
One of the sellers responded to my email that I have to change the whole bike and sent ma link to buy a frame for £1499.
So yeah... Not cool.

The bike I have:

The frame (S)

1612824666590.png



I really need help, I have no idea how to solve this issue and I can't afford to change the whole bike :/
My budget is 500, max £550.


I would appreciate any help!
Thank You, Riley
Use the Topek Versa Mounts on the underside of the downtube for the battery. You have plenty of room there for a cage. Weight will be low and centered. Use a torque sensor mid-drive motor. One of these will effectively give you 300Watts from a 250W motor because they are more efficient and weight will also be low and centered.
 

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Pedaluma

Pedelecer
Sep 28, 2020
30
6
Please show the test data where you get that from, otherwise I call com[plete ballcox.
Firstly I have no data as proof that mid-drive motors are lower and more to the center of a bike than hub-drive set ups. You have me there.
The difference is in the feel at starts and on hills. I am in the San Francisco area, so go on a group ride like we do with both kinds of bikes and find out for yourself about how they feel. We are doing a Covid-safe group ride Thursday AM. Launch a hub-drive into a hill alongside some mates on mid-drives then you will know.
 

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FJC71

Pedelecer
Mar 1, 2020
36
12
Looking again at your budget I think you can forget the rack option. I also think the mid drive option is doubtful with regards to your bottom bracket (you should check that). Mid drives tend to be more expensive as well that might be a factor. Lastly with regard to mid drives, you intend to commute , you require reliability, hub drive as a whole tend to be more reliable based upon the feedback you get on forums. I would say if you were going to use the bike for fun and for off road a md drive would make more sense but not for what you propose.

A figure of 12wh per mile is often quoted for the average rider for battery usage, if your younger and fitter you might do better. Your daily distance will be 22miles? you will need around

12 x 22 = 264 wh

Allowing for a maximum usable capacity of 80% thats a minimum of 330wh battery. In reality I would want a bit more at least 400wh. That means a minimum battery size at 36v of about 9ah for the lower figure 11 for the higher. Smaller 7ah bottle batteries might work in space terms but could be tight for range. You could recharge at work but that would mean carrying the charger or a second charger stored at work.

Given the above I think you should be looking at a geared hub drive with a battery of 10ah minimum

If after checking a standard frame battery does not work (the best option if it does) that leaves you two possibilities.

1. A softpack in a bag.
Or possibly the best
2. The frog battery proposed by Woosh.

The quoted price of £299 for the small frog battery is actually not bad considering the capacity of the battery. He doesnt quote it on the website but speak to him and see if he will do a suitable hub based kit based on the small frog. The prices quoted for a frame battery on the Woosh site suggest it might be within or close to your budget if he does it.

A complete kit will be better than a motor and battery from different sources as there will be hidden costs in the latter, such as making up adapters, extensions to the wiring etc. Sourcing from Woosh you will have confidence in the battery and some back up if you need it.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,950
Basildon
Firstly I have no data as proof that mid-drive motors are lower and more to the center of a bike than hub-drive set ups. You have me there.
The difference is in the feel at starts and on hills. I am in the San Francisco area, so go on a group ride like we do with both kinds of bikes and find out for yourself about how they feel. We are doing a Covid-safe group ride Thursday AM. Launch a hub-drive into a hill alongside some mates on mid-drives then you will know.
That's rubbish. It depends what type of hub motor, what speed it's wound for, how much current you give it it and at what voltage it runs. You're making sweeping statements based on very limited knowledge. We used to get a lot of myths like that spread on this forum about ten years ago, but they had died out until you have tried to resurrect them. It's a complete fallacy that mid motors are any more efficient than a hub motor. There were tests done by a German ebike magazine that proved the opposite of what you're saying.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
16,938
6,612
59
West Sx RH
How about the hill climbing challenge that used to take place in Brizzol, a hub bike beat a Bosch drive to the line.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,950
Basildon
How about the hill climbing challenge that used to take place in Brizzol, a hub bike beat a Bosch drive to the line.
Hub-motors won every year they did it. In fact, I'm pretty sure that they won every single event. IIRC, a Bromptom with an ordinary QWSXK5 motor running at 48v won in the penultimate year. The Oxygen MTB with a Bafang CST motor won the last event.
 

hey_pavel

Finding my (electric) wheels
May 1, 2020
9
4
We can produce a kit for your bike with a seat post or handlebar mount - vekkit.com .
 

Pedaluma

Pedelecer
Sep 28, 2020
30
6
Rileyy,
Convert an S-Works Turbo Levo over to a hub-drive for enhanced performance because engineers at firms such as Specialized and Santa Cruz obviously do not know what they are talking about. What were they thinking?
 

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