I came, I saw, I want one!

[Arash]

Hello every body,

I am considering an electric bike for a 9 mile commute to work. I can't afford or want a ready made solution, I had much rather struggle with making bits work that weere not intended for the purpose than buy a shiney one out the shop.

I will be pestering all and sundry about the differences between the wheel hub or centre motor kits etc...

I am an electrical engineer and work in central london, I have built some stuff before, so getting my hands grotty is a big part of the attraction of the project.

Any hoo

Cheers

 

[soundwave]

http://em3ev.com/store/index.php?route=product/product&path=45&product_id=187

 

[Deleted member 4366]

You can get that same kit from the UK for a lot less than from Em3ev.

 

[soundwave]

got a link so how fast will the 750w go, you fitted any ?

 

[Deleted member 4366]

http://www.eclipsebikes.com/bafang-8fun-bbs02-drive-750w-motor-p-1100.html
http://wooshbikes.co.uk/cart/?cdkit

You should be able to reach 30 mph. If you want to cruise at over 25 mph, you need a better battery.

 

[Nealh]

London 9 mile commute so fairly flat with no hills ? Weekend use or leisure ?
Fitness and weight and bike style.

 

[Cyclezee]

Hello every body,

I am considering an electric bike for a 9 mile commute to work. I can't afford or want a ready made solution, I had much rather struggle with making bits work that weere not intended for the purpose than buy a shiney one out the shop.

I will be pestering all and sundry about the differences between the wheel hub or centre motor kits etc...

I am an electrical engineer and work in central london, I have built some stuff before, so getting my hands grotty is a big part of the attraction of the project.

Any hoo

Cheers

Hi Arash,

Welcome to the forum.

I think your requirement to make bits work that were not intended for the purpose might prove tricky as all the readily available kits are actually intended for the purpose. Don't let this put you off though.

 

[soundwave]

man the batt prices kill it ;(

tho if you can build them what would it take to get to 100mph ? is it even possible ?

 

[Deleted member 4366]

Now up to 120mph average.

 

[Arash]

Thanks for the replies and the welcome, I was actually looking at the bafang kit but was not sure if it was any good.

Couple of answers to questions posed:

My bike is a 15 year old hardly used but "weather conditioned" raleigh mountain bike. It was about £500 when I bought it but it needs new chain and pair of wheels, I will upgrade the v brakes to some nice disks and the forks will get ditched for new ones.

Its a nice down hill 9miles to work and all uphill home, I am reasonably fit as I walk about 6 or so miles per day, I am what I delicately call extra lard arse!
Hence why I am considering one of these kits.

I have also got access to lots of 18650 lithium ion cells, I also know a man with a 3d printer who can print any housing or other bits I need, just need to find a proper charger, the cells are a nominal 3.7v at anything from 1ah to about 2.6 ah, 11-12 series will output 40-46 volts and I can parallel the packs to get what ever capacity I need, 10 packs of 11 cells will give me some thing like 20-24ah (usual battery performance caveats apply) each cell weighs 45g so a pack of 111 including plastic housing and cables etc will weigh about 5.2 kilos. I could go with lipo but the 18650's are more or less free.

I have the facility to give them an 8 hour charge at work as well as work and plenty of space to store extra packs as I make them.

I will more than likely only use it for the work commute, weekends I will give my sore arse a rest! Haha

Any way thats the plan so far.

 

[soundwave]

Now up to 120mph average.

how much for 1 of them tho?

i want 300mph now lol

 

[jonathan75]

I thought discs were superior but then found not only did my v brakes grip better and squeak less, but the rear disc stopped my pannier rack and mudguard fitting (and to think I paid for this privilege too!)

On London roads suspension forks are not a bad idea!

 

[Croxden]

I thought discs were superior but then found not only did my v brakes grip better and squeak less, but the rear disc stopped my pannier rack and mudguard fitting (and to think I paid for this privilege too!)

The rim of your wheel is a big disc and should work better, until the rain and mud get a hold. And they wear the rim away & then you will need a new wheel unless it collapses and stops you from biking ever again.

 

[RobF]

The rim of you wheel is a big disc and should work better, until the rain and mud get a hold. And they wear the rim away & then you will need a new wheel unless it collapses and stops you from biking ever again.

The rim acting as a big disc is a very good point.

Decent V-brakes properly mounted provide plenty of stopping power.

Longer drop Vs have more leverage, and the legs themselves need to be rigid - some of the cheaper ones flex.

Against that is rim wear, and if the wheel goes slightly out of true the brakes will rub, which they won't with discs.

On balance, I think hydraulic discs are better for an ebike, particularly a hub motor one on which replacing the motor wheel is more complicated.

 

[mfj197]

I have also got access to lots of 18650 lithium ion cells, I also know a man with a 3d printer who can print any housing or other bits I need, just need to find a proper charger, the cells are a nominal 3.7v at anything from 1ah to about 2.6 ah, 11-12 series will output 40-46 volts and I can parallel the packs to get what ever capacity I need, 10 packs of 11 cells will give me some thing like 20-24ah (usual battery performance caveats apply) each cell weighs 45g so a pack of 111 including plastic housing and cables etc will weigh about 5.2 kilos. I could go with lipo but the 18650's are more or less free.

Although you don't need anything like that capacity for a 9 mile each way commute, especially if you are charging at work as well. I'm doing a 21 mile each way commute in to SW London and use half of an 11.6Ah pack each way. That's 10 cells in series (the most common requirement), 4 parallel, weighing 2kg.

I was actually looking at the bafang kit but was not sure if it was any good

I use the 250W version on assist 3 out of 5 and find it very good. It was a relatively easy conversion, is virtually silent and works well.

Michael

 

[Arash]

Thanks for all the advice, had a go on a kalkhoff today, one of the guys at work uses it. Very nice but it costs more than my car and it will probably get nicked.

So project Ginga is about to take off!

http://s374.photobucket.com/user/kamaangir/media/image.jpg1_3.jpg.html

Its looking sorry for itself after sitting in one garden after the next. But all the rusty bits will get replaced, I liked the idea of the hub gears and the hydrolic v brakes on the kalkhoff... Depending on how much money I have left.
Found a company on aliexpress selling a frame mounted battery housing for $40 plus shipping but it can only hold 50 batteries, its a very neat solution.

I have decided to go with the bafang bbs02 48v kit.

Hoping to get it done with the help of a mate, who's into fixies, and vintage bikes, before the next tube strikes on the 5th of august.

 

[destructimo]

Don't forget to add the boring stuff that makes the bike pleasant to commute on, such as road tyres with puncture resistant strips built in, full close fitting mud guards, rack with luggage and decent lights!

Enjoy, converting a spare decent bike with a good kit gives you an excellent and inexpensive machine.

 

[Arash]

Yep ordering these tyres tonight:
http://www.wiggle.co.uk/schwalbe-city-jet-mtb-tyre/

Looking for a new pair of 26" wheels, some decent pads for the brakes, new chain and I will see what else I can get cheap.

Got an imax b6 and an nitecore d4 individual cell charger, got a bench power supply on its way too. Just chasing a bloke for a load of 18650's that he had ammassed and never did anything with.

And last but not least an extra wide sadle for my extra lard arse haha, oh and ditching the spd pedals for some normal ones.