Advice wanted for choosing a kit

[JT101]

Hi Everyone

I am looking for a conversion kit for my existing bicycle. I am mechanically minded, so fitting a kit will be straight forward, but I wouldn’t be capable of building a kit from scratch i.e. separate controller, LCD etc etc.

This is my ideal wishlist:

Top speed on throttle – min 20mph
Range: 30miles (on full assist level)
Bottle style battery
As small a profile motor as possible
Low maintenance

My commute will be 12 miles each way, so 30 miles should leave me a bit in the tank if I make a detour. The route is fairly flat. Definitely no major hills.
My budget is only about £500, and for this I would like to buy a full kit from one of these good quality Chinese importers such as BMS battery, although I’m happy to buy direct from a reliable Chinese business. I am not looking to spend more money for the benefit of UK customer support.
I have been leaning away from mid drive because of the lack of big hills on my route, the additional cost and maintenance involved. I am thinking front motor, only because of the all wheel drive with my legs powering the back, and the battery located in the middle of the frame.
I would really like a round bottle style battery, and I’m thinking for such a long commute, 15Ah is a minimum really. Any more and it would be too heavy / expensive.
I would like a top speed of 20mph so that I can add my own leg power to take it to 22 – 23mph
Having done a fair bit of research I believe I’ve come up with a reasonable spec, but would like some comments or recommendations of what to buy and where to buy it please.


36V 15A 500W Brushless geared motor
15Ah Panasonic bottle battery

 

[wesnewell]

Take your pick.
http://www.ebay.co.uk/sch/i.html?_from=R40&_sacat=0&_nkw=48v%201000w%20rear&LH_PrefLoc=1&rt=nc&LH_FS=1&_trksid=p2045573.m1684
And for a 30 mile range at 20 mph you'll want a 15ah 48V battery pack minimum.

 

[dogman dan]

Or a 36v 20ah. But you can use a smaller battery if you can charge it at work.

The budget might be too small, even direct from china. But you should be able to snag a 36v kit and 36v 10 ah battery pretty affordable from bms battery or somebody with similar prices. Then maybe add a second battery later when you can afford it.

 

[Jon NCal]

Just to note, if your motor is 20mph top speed, it won't be giving any useful power when you are pedaling 22-23mph. So best to get 24-25mph motor @ your chosen battery voltage.

 

[JT101]

I am willing to increase my budget £100-200 if the kit was good enough

Those Ebay links you sent, I wouldn't know if they have a good reputation or are good quality

 

[dogman dan]

It's close your eyes, click buy, and hope for the best in your price range. However, the cheaper stuff with potentially higher defect rates still have most of the customers get working stuff.

Up your budget, and you can go to reputable vendors like EM3ev for your kit.

One thing to take note of, the battery for a 1000w kit will have to cost more than a battery for a 250w kit. 20 mph takes 400-600 watts. So aim for a 36v kit, that will do 20 mph without needing expensive cells. You'll still need the size to make your distance, but at least you won't have to pay for the very best cells.