Electric cruiser - Not the norm

Lordlucan

Finding my (electric) wheels
Oct 8, 2015
5
2
45
Hi,

I've been a bit of a lurker for the past few months, so forgive me for my relative newness.

I have built a cruiser bike, similar to: http://i90.photobucket.com/albums/k245/firebikes/DSC03023.jpg

It's quite a heavy steel frame. I have used bmx components, 26" mountain bike wheels on 2.3 schwalbe tyres, put disc brakes on, an old sprung brooks saddle and then put a 250w 13ah kit from electric bike conversions. It's a bit of a fun handsome Frankenstein. The battery is carried in a formed rucksack on my back.

At the time of buying the kit I was looking at the oxydrive 13ah kit but they were not in stock and I figured I would get it running and then, if needs be, at a later date then change the kit. So, in summary it's quite a heavy single speed bike. I'm 6'3", perhaps 13-14 stone.

It's been built for about a month and I have been waiting for a friend to complete a similar project. I couldn't wait any longer on Sunday and so went out for a ride and covered about 7-8 miles. Overall, was a pleasant experience, there's a few minor issues that need ironing out, but the pedal assist and throttle work and it gets to about 15mph on the flat (I think). Living in quite a hilly area though did expose the main issue, climbing power. I did not expect that it would be a throttle on and carry me up the hills but I was a bit underwhelmed by its ability when tackling a gradient.

By way of a sort of comparison I have previously ridden a Pedego which, whilst more of an ergonomic ride and probably lighter, was much more capable on the hills.

So, what to do? I know that I am not allowed to exceed the 250w, being a UK resident, but I need it to be more capable on the hills. A 500w kit would not be sensible given that, even in my short Sunday excursion, the bike attracted quite a lot of attention.

1 - Have I bought a good kit?
2 - What would you recommend I do in terms of modifying the kit?
3 - Is there a more suitable kit i.e oxydrive?
4 - Would using a higher voltage battery help?
5 - Do any of you experts live in Gloucestershire fancy a cup of tea at mine to have a look at what I have built, and provide some pointers?

I can probably add a photo of it later.

Thank you in advance.
 

JohnCade

Esteemed Pedelecer
May 16, 2014
1,486
736
250w is a purely nominal figure and most motors produce far more at peak power. A BPM motor or equivalent would have been much better for you. Oxygen do a very good kit which makes for a powerful hill climber, and that may have been the one that was out of stock. Woosh and others will sell you a powerful motor kit without you needing to end up with an illegal bike..

What you have discovered is that not all 250w motors are equal, and some are very much more powerful than others.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,917
8,533
61
West Sx RH
Lurking for a few months but missing for about 40 odd years :D.
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
20,917
8,533
61
West Sx RH
Can you post a link to the actual kit you got, Do you know if its a geared hub or direct drive hub ? Both types of hub are different in the delivering of their performance.
 

Lordlucan

Finding my (electric) wheels
Oct 8, 2015
5
2
45
I always like using the username 'lordlucan' but it did upset someone enough on ebay that they would not do business with me, haha. I did try to remind them it was just a bit of fun.
 

Alan Quay

Esteemed Pedelecer
Dec 4, 2012
2,351
1,076
Devon
Looks like an SWX but can't be sure. Certainly looks like a geared, brushless DC motor.

As others have said, a BPM/CST would be better.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,917
8,533
61
West Sx RH
Certainly not a D/D hub to small and as Alan says is a swx freewheel or similar ok for lightweight person or lightweight bike not really able to cope with steep or long hills. For your weight certainly a bpm or cst will be more powerful for hill climbing something with a winding between 230-270 rpm that way you get good torque for pulling and good speed for the flat ( 18-19mph), a lower winding will give better Torque but a few mph less and a higher winding will be the opposite. Your battery at 13ah should be ok depending on the quality of the cells inside Samsung and Panasonic are good.
Answering your original Q's.
1. It is an average kit not really for hill climbing.
2. You can tweek the controller to give a few more amps but that may
wreck your hub motor.
3.The Oxy kits the 11ah kit uses a smaller cst but better then your one, the 13ah is high torque(said to be 270rpm) & high speed 24mph.
Woosh bpm kit is high torque but 350w, speed 19/20 mph.
Cyclezee kits are powerfull and quality and legal.
Also Pandabikes sell the Xiongda 2 speed kit for hill climbing same size as yours but stronger and powerfull, speed 19/20mph.
4. 48v would give you 30% more torque and speed but may be too much for that hub but would be ok on a bigger 36v hub like bpm/cst. or Xiognda.
5. Me no.
Try applying the throttle as you peddle to see if it helps.
 
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Lordlucan

Finding my (electric) wheels
Oct 8, 2015
5
2
45
Thank you all. This is massively helpful. I will go and do a bit of further research and let you know how I get on. It was always going to be an ever evolving project...
 

Lordlucan

Finding my (electric) wheels
Oct 8, 2015
5
2
45
Guys, I just wanted to thank you for your help. I purchased an oxydrive kit. It is very good. Hill climbing and top speed are vastly improved. Mine is the front one. Only a few jobs left before it is finished. FB_IMG_1469229231208.jpg
 

D8ve

Esteemed Pedelecer
Jan 30, 2013
2,142
1,294
Bristol
Nice bike, isn't it going to be a bit easy to spot you on that:eek: