matt912836
100 W
I recently purchased a Kona Kikapu FS frame of CL to build my next ebike on. Came with a Fox rp23 rear shock. I chose full suspenison because with past experience, anything faster than 24mph on a hardtail is uncomforting hitting the slightest bump. I also want the ability to do some very light off roading and have no problems hopping off curbs and not having to baby the bike. With this setup I am planning to use 4-6 36v 4ah batteries mounted in the triangle. How they are wired depends on which route I take on the motor. I want this setup to have good low end torque, and a top speed of 25-30mph (don't see the point of going FS if any slower). I'm also looking for the most efficient setup possible to maximize range. I DON'T want to throw thousands of watts into a motor, 500-1000 max, so it will definitely have to use the efficiency of using gears. Not trying to bust the bank either, this is a budget build. With that in mind, I'm looking at two options right now:
[strike]A brushed geared mid drive kit:
http://www.ebay.com/itm/24V-350W-DIY-MTB-Electric-Bicycle-Accessories-Kit-Geared-Brush-Motor-Conversion-/151872590818?hash=item235c4fd3e2:g:cCEAAOSwKsRWFhCu&vxp=mtr
Or, a brushless geared hub motor:
http://www.ebay.com/itm/36V-500W-Geared-26-Front-Rear-Ebikeling-Electric-Bicycle-Conversion-Kit-ebike-/271923152076?var=&hash=item3f4fe204cc:m:mDQBWD22DB6VOvwhv_g145g
For the brushed kit, I chose the 24v 350w version since it will spin faster at 36v than the 36v 350w version. I don't care about noise, if anything I'd rather you hear me coming when I'm at speed than be silent. Hopefully that will get me somewhere in the 25+mph range, as its supposed to do around 20-22 stock. Since its a mid drive it will inherently have lots of low end torque in the right gear, do you think I can acheive 25mph+ with a 24v motor @ 36v in one of the highest gears? Ill wire all the batteries in parallel with this setup and about 500w. Only thing about this setup is the way the motor mounts to the bottom bracket, the rear suspension pivot is right above the bottom bracket and might get in the way and require slight modification of the mount.
If I chose the brushless kit, I was planning on swapping out the stock 36v 500w controller with either a 72v 500w or 72v 800w controller to acheive a higher speed. I wouldn't want to go past 800w on this 500w motor to avoid any burning out issues. How would this motor perform with double the voltage with the same or a little more wattage? Since its geared and higher RPM's are always better with geared I assume it would have better low end torque and a higher top speed with around the same amount of wattage, just bumping up the voltage and trying to keep the watts under 800. One thing i did notice is the dropouts on the kikapu are very small and circular, no "flatness" or "deepness" to hold the flat part of the hub motor axle firmly, what can I do about this? I'd assume i'd need torque arms if i plan on going to 72v even if it is less than a thousand watts. Could someone recommend torque arms that would be good for the kikapu?
Any input is appreciated![/strike]
I've decided on a mid drive approach, this mid drive kid by SBP seems to fit the bill at a decent cost:
http://www.sickbikeparts.com/catalog/product_info.php?cPath=26&products_id=180
Has a 36-72v external controller vs the internal in the bbs02 that can't go past 60v.
Also seems to be more adaptable to my frame's bottom bracket.
[strike]A brushed geared mid drive kit:
http://www.ebay.com/itm/24V-350W-DIY-MTB-Electric-Bicycle-Accessories-Kit-Geared-Brush-Motor-Conversion-/151872590818?hash=item235c4fd3e2:g:cCEAAOSwKsRWFhCu&vxp=mtr
Or, a brushless geared hub motor:
http://www.ebay.com/itm/36V-500W-Geared-26-Front-Rear-Ebikeling-Electric-Bicycle-Conversion-Kit-ebike-/271923152076?var=&hash=item3f4fe204cc:m:mDQBWD22DB6VOvwhv_g145g
For the brushed kit, I chose the 24v 350w version since it will spin faster at 36v than the 36v 350w version. I don't care about noise, if anything I'd rather you hear me coming when I'm at speed than be silent. Hopefully that will get me somewhere in the 25+mph range, as its supposed to do around 20-22 stock. Since its a mid drive it will inherently have lots of low end torque in the right gear, do you think I can acheive 25mph+ with a 24v motor @ 36v in one of the highest gears? Ill wire all the batteries in parallel with this setup and about 500w. Only thing about this setup is the way the motor mounts to the bottom bracket, the rear suspension pivot is right above the bottom bracket and might get in the way and require slight modification of the mount.
If I chose the brushless kit, I was planning on swapping out the stock 36v 500w controller with either a 72v 500w or 72v 800w controller to acheive a higher speed. I wouldn't want to go past 800w on this 500w motor to avoid any burning out issues. How would this motor perform with double the voltage with the same or a little more wattage? Since its geared and higher RPM's are always better with geared I assume it would have better low end torque and a higher top speed with around the same amount of wattage, just bumping up the voltage and trying to keep the watts under 800. One thing i did notice is the dropouts on the kikapu are very small and circular, no "flatness" or "deepness" to hold the flat part of the hub motor axle firmly, what can I do about this? I'd assume i'd need torque arms if i plan on going to 72v even if it is less than a thousand watts. Could someone recommend torque arms that would be good for the kikapu?
Any input is appreciated![/strike]
I've decided on a mid drive approach, this mid drive kid by SBP seems to fit the bill at a decent cost:
http://www.sickbikeparts.com/catalog/product_info.php?cPath=26&products_id=180
Has a 36-72v external controller vs the internal in the bbs02 that can't go past 60v.
Also seems to be more adaptable to my frame's bottom bracket.