# Ghetto mod electric bike - a bit of a BLOG



## BenScoobert (26 May 2016)

The other day someone offered to give his mountain bike away. I held off a couple of days and no one took it, so I said I'd like to have it to try an electric bike ghetto set up.

So here we are, step 1, I got this bike today. I say bike......BSO......gift horse and all that.
Now this thing is for playing around in the park and just dicking around in general, it's not for road use as I have my pride and joy for that. So we totally disregard this 250w nonsense, 1000w is available so no point going for less I think, per wheel I might add, so firstly I'll get it rigged up with something, then see where this goes.

I have about 12 6s 5ah lipos, so I plan to use them in a 48v system, I'm guessing 8 of them are fit to use in this, 4 are a bit tired. So that's 20ah at 48v.

I'm probably going to end up with something along these lines
http://www.ebay.co.uk/itm/48V-1000W...875424?hash=item25ae688560:g:y70AAOSwgQ9VvQLg

Anyway, enough for tonight, bedtime, tomorrow I'll give the bike a look over and check my batteries.
In the meantime feel free to share any knowledge for advice you have.

PS. Anyone considered you could fit 2 1000w wheel driven systems and another 1000w on the BB, y'know, just for shoots n giggles.


----------



## ufkacbln (26 May 2016)

IIRC the 250 is for tricycles and tandems, it is 200W for a bicycle

It is also restricted for "use on private land" so I believe you would still be illegal in a park


----------



## BenScoobert (26 May 2016)

Cunobelin said:


> IIRC the 250 is for tricycles and tandems, it is 200W for a bicycle
> 
> It is also restricted for "use on private land" so I believe you would still be illegal in a park



AH well 

It hasn't stopped raining all morning so the bike is still in the car, it's been an online research day. I don't fully understand what this means
- The rear drive motors are only compatible with a 3speed, 6speed, 7speed and 8speed freewheels (not compatible with a cassette type gear. I.e. if you have a cassette, this needs to be swapped to a freewheel, a local bike shop can help you with this). If you have a single speed bike, you can install a 3speed freewheel for compatibility (and use only one of the 3 speeds).


----------



## Pale Rider (26 May 2016)

Use of an illegally powered bike is illegal on any land to which the public has access.

This includes land which is otherwise private, ie a field, unless the field is fenced and gated, preferably with a lock on the gate.

Effectively, the bike is unusable legally just about anywhere.

The legal power limit is 250 watts for a bicycle and the assist must cease at 15.5mph - 25km/h.

On the technical side, many rear motors can only be used with a freewheel - not a free hub - which usually limits you to seven gears, although there are a handful of eight gear freewheels..

All modern nine, 10, 11 and now 12 gear cassettes are free hubs.

Some newer motors work with a free hub.

No such restrictions on a front hub motor, but getting a high powered motor to stay in the front drop outs can be difficult.

As you may imagine, the motor spinning out of the drop outs at speed is not good from a safety point of view.


----------



## Tanis8472 (26 May 2016)

Totally inaccessible to public, with land owners permission. 

Edit
Really should refresh page before posting lol.


----------



## BenScoobert (27 May 2016)

Progress 

http://www.ebay.co.uk/itm/E-bike-co...hash=item3d192d1ca3:m:mCmYxaJwKvMoGclOAeZ3s2g
this kit ordered with the extra LCD screen and peddle assist sensor, total £280
should be here wednesday




Pale Rider said:


> On the technical side, many rear motors can only be used with a freewheel - not a free hub - which usually limits you to seven gears, although there are a handful of eight gear freewheels..
> 
> All modern nine, 10, 11 and now 12 gear cassettes are free hubs.
> 
> ...



we'll try the rear 1st, then maybe the front after  2wd!!

As for gearing, this BSO only has 3x5, but I'm thinking with 1000w of boost I might only need 1 gear!! I have another donor bike at my mum's, I think it might have 6 speed rear mech, I'll check today.


----------



## raleighnut (27 May 2016)

Cyclotricity are good kits, we've got 2, both 250w front wheel kits though 1 on my Trike and the other on Maz's Dawes 'Geneva'.


----------



## Pale Rider (28 May 2016)

Cyclotricity are decent kits as @raleighnut says.

However, the 500w/1000w ones use direct drive motors which do not climb at all well.

It will give you the speed you want on the flat, which may be where your proposed hooning about use will take place.

But should you tire of that and want to progress to cross country trips, you should prepare to be disappointed.

Nor should you be taken in by the legal/illegal button.

Ultimately, the kit is not legal for use in any remotely public environment, no matter how it is set up.

In other words, it is not like a car which can do 100+mph but is legal to use provided you don't exceed the speed limit on the road you are on.

I have not heard of anyone being prosecuted for using an illegal ebike, but that doesn't mean it has not or will not happen.

Practically, if you are pedalling along illegally assisted at 15-20mph - fastish roadie pace - you are unlikely to attract any attention.

But if you go barrelling down your local high street at 30mph with your feet on the handlebars you could easily get nicked.


----------



## BenScoobert (2 Jun 2016)

Build day!!

Today I got the bike to a stage where I can test it with 250w of power.

As you can see from the pics, the wheel is nice and tidy, the loom is tidy with a single cable to the handlebars which then splits into 4.

Tomorrow I'll mount the rack I dug out and work out where I want all the transformer and batteries sat.

I had a little ride around, it made hills feel like flat, I guess it was about 1 in 6 hill I tried, it didn't convey me without pedalling but I didn't get out of breath.


----------



## raleighnut (3 Jun 2016)

BenScoobert said:


> Build day!!
> 
> Today I got the bike to a stage where I can test it with 250w of power.
> 
> ...


I would have gone for the rack mounted battery option, well worth the extra (£100 ?) there won't be that much range with the smaller battery pack.


----------



## BenScoobert (3 Jun 2016)

raleighnut said:


> I would have gone for the rack mounted battery option, well worth the extra (£100 ?) there won't be that much range with the smaller battery pack.



The rack mount ones are £400, I only used small packs for testing, I actually have a lot of these packs, I'll probably be using 15-20ah worth.


----------



## raleighnut (3 Jun 2016)

BenScoobert said:


> The rack mount ones are £400, I only used small packs for testing, I actually have a lot of these packs, I'll probably be using 15-20ah worth.


so you just bought the Motor and Controller then, The 2 I have were complete kits but I left out the bar mounted assist computer and the crank sensor and just run em on the thumb throttle (front wheel kits)


----------



## raleighnut (3 Jun 2016)

This is my Trike with the 250 watt front wheel kit







The 'curly' lead is for the twin lampset on the front, nothing to do with the Cyclotricity kit.


----------



## BenScoobert (3 Jun 2016)

raleighnut said:


> This is my Trike with the 250 watt front wheel kit
> 
> 
> View attachment 130540
> ...



I got the kit with 48v 1000w motor and controller, thumb throttle and brake levers which cut power. Optional extra LCD screen and pedal assist sensor. 

The pedal assist sensor will have to wait for now as I can't get the crank arm off.
Also the pedal assist sensor cable is so short it limits you to fitting the power controller to the seat post. I had wanted to put in on the rear rack. 

I'm just about to solder a lead which will sit all 8 batteries in 2s 4p configuration using EC5 connectors.


----------



## Pale Rider (4 Jun 2016)

BenScoobert said:


> Build day!!
> 
> Today I got the bike to a stage where I can test it with 250w of power.
> 
> ...



Well done for getting up and running.

Fitting a kit requires some creative fettling.

Fine if you know what you are doing, but it would defeat a lot of us.

I see you also seem to know what you are doing with batteries, which is another big plus.


----------



## Tanis8472 (4 Jun 2016)

Aiming for 2.5hp on something weighing maybe 125kg including rider  

20hp per ton. That should go like snot


----------



## BenScoobert (5 Jun 2016)

Tanis8472 said:


> Aiming for 2.5hp on something weighing maybe 125kg including rider
> 
> 20hp per ton. That should go like snot



Right now it is about 113kg me + 25kg bike with 1kw/1.34bhp
it propels me to 27mph in no time, the gearing on this bike doesn't allow pedalling over 20 mph, I found a sweet spot is to limit it to 16.5mph.

I still need a crank puller to fit the cadence sensor


----------



## BenScoobert (5 Jun 2016)

Pale Rider said:


> Well done for getting up and running.
> 
> Fitting a kit requires some creative fettling.
> 
> ...



The fitment was fairly straight forward TBH, the cyclotricity kit seems quite simplified compared to some.

As for the batteries, I have radio controlled helicopters, the batteries I use are capable of delivering about 2.5kw each, so this is a walk in the park for them.
That's the difference between lithium ion and lithium polymer, on the downside they are far more volatile and subject to careful charging.
Each of my packs is 5AH 25.2v (6S) that means 6x 4.2v cells in serial. I used 2 packs to give me a theoretical max of 50.4v in 12S.
Then I plan to run pairs on packs in parallel which will up my AH, to if I use 4 pairs of packs I'll have 20AH.
20AHx50.4v = 1008WH this is 1.008KWH meaning I can run 1KW for an hour and fully drain the packs, or a 4 hour 250w discharge.

I wouldn't drain the packs fully as it doesn't do them any good, a good rule of thumb is 80% discharge. Which ties up nicely with the low voltage cut off of the kit.


----------



## BenScoobert (4 Oct 2017)

This is now for sale in the classified section


----------

