What am I missing ?

[Kuorider]

Being new to this stuff, I see an e- kit for my wife's folder will cost around £450. Shopping around I see a little e-something folder being sold under different names from £375 to upwards of £700. So I buy the cheap one ,take of the 'kit' and revamp the donor as a push bike for the local charity shop. Then fit the kit to the good quality custom built folder constructed for my little lightweight, fit ,but oldish wife to toddle along cycle paths at 10mph max for a few miles in the sun.. Can it be this simple or am I missing something... ?

 

[Deleted member 4366]

It is that simple, but there's always a few obstacles. You need to check the width of your forks. The Tesco Hopper will be 100mm. Many lightweight folding bikes have 75mm forks. You might also meed to change your bottom bracket to a wider one to accommodate the pedal sensor, and you need to check your seat-post diameter is the same for the battery clamp.


Why would you need to change all the stuff over. There's nothing wrong with a Tesco Hopper

 

[Kuorider]

Hi,d8veh, Thanks for your reply, The forks are indeed 100mm ,on your other points, these are not a problem as I can fabricate & machine items in my own workshop. The bike issue is simple, the folder is based on a Xootr Swift, modified with lower gearing ,shorter cranks, double chainwheel, improved brakes ,self presenting clipped pedals, thudbuster stem sleeved to suit the frame and custom made steering stem for shorter reach, comfort saddle, gel grips on wider alloy bars. Built to suit my wife who has minor age related issues . By comparison the hopper is a bit ordinary. There is a kit available for the Swift at £800 which seems a bit much given that the only special item is the shaped battery . I do much appreciate your interesting posts on here,especially the electrical stuff.

 

[Deleted member 4366]

It's probably cheaper to buy a kit. You have a nice bike, so why not get a nice kit to go with it. You can get one from BMSBattery or Greenbike kit for a lot less, and with a better control system. If you want UK support, a basic Cyclotricity kit is £399, or £450 with the LED control panel.

Those Tesco Hopper type bikes only have a 24v battery, so power and range is limited.

 

[Kuorider]

Hi,Again. I am on a learning curve here .Looks like a new hobby opening up now . I have been looking at the Cyclotricity kits and their good reputation helps also. I did not know of the others until joining here. It all gets more interesting by the day. I see your point on range but is the power not limited to 250 watts regardless of the voltage on legal bikes. In this particular case low range and power may suit perfectly. Thanks once more for your help.

 

[Deleted member 4366]

You can't take any notice of the 250w rating. There's three important factors for a hub-motor: The voltage, the current and the winding speed (RPM).

Most cheap 250w systems use a 12, 14 or 15 amp controller, so to compare, you could have 12 amps at 24v (actually about 28v) or 15 amps at 36v (actually about 40v). The power from the battery could therefore be 336w or 600w, which is roughly double. Then, there's more expensive kits like the Ezee kit with a 20 amp controller that draws 800w from the battery, or even the "200w" Heinzmann with a 30 amp controller for 1200w.

 

[Kuorider]

Hi,Again, Thanks for that info ,I will need to bull up on fractional DC motors .I see where the proper controller fits in now.
I done a few miles on the Kuo this afternoon,it's a 24 volt unit and I find the performance very good. The forest behind here climbs over 300 ft in about 1/2 mile and I can do this easily in low gear. Bear in mind that I am 70, 72kg and the road is smoothish ,I was not even breathing hard, this is a great way to toddle around. This run was getting beyond me on the MTB even in max granny mode. I can feel an upgrade coming on !!

 

[Kuorider]

UPDATE.. I decided to look around for a complete donor bike following the help given here. Searching around the internet turned up a seller offering new eco go bikes for £300. these were advertised as 'open box' having minor faults. Fine by me as I just wanted the kit which was guaranteed to be A1. The seller had excellent feedback and answered emails fully and promptly . Two days later the box arrived with an unmarked and obviously new bike complete with battery ,charger, paperwork etc. Only faults I could find were gears well out of adjustment one soft tyre and the handlebars stuck out of line due to the wedge needing freed off. Actually as D8vh pointed out a surprisingly nice bike and worth every penny. All parts swopped over with no problems leaving a complete manual bike which my Daughter has commandeered for herself. So all in a complete kit and a bike left over for £300 is a good start in messing around with electric bikes. I decided not to convert the Xootr and instead used a small alloy folder which suits my wife better. now have a Xootr left and eyeing up a suitable 'off road' conversion.