mwkeefer
1 MW
Hello all,
This is to document my latest build on a 2009.5 DownTube 9FS Folding Bike (http://www.downtube.com/Full_Suspension_Folding_Bike.html).
Version .01 Alpha
This is the 9FS without a sprocket/freewheel on the e-bikekit.com 9c rear motor. Note the LiFePo4 battery attached to a rear walmart clamp on rack - note the duct tape, this is Ghetta Fabulous. Also note the bags strapped to it as if it were a pack mule (bags contain: freewheel, replacement pull brake pads, misc replacement parts)
Version .02 Alpha
So now this is rideable but I must start calling it my Downtube FS or 1FS. Note the chain is now working but I have alot of truing to do on the rear wheel (this is not indicative of e-bikekit.com wheels but I took this from a fresh delivery off the truck so it hadn't been addressed by their staff for truing or tensioning, all customer orders are trued before shipping but I was in a hurry and said I would do it myself.) The Transit trunk bag holds 15S2P of LiPo but I only run a single 1P at a time while testing. This is still Ghetto and the brakes need work, the stock brakes may have been ok at 28lbs but by going to nearly 50lbs I have really pushed them past the working point - next upgrade is front disc brake then I will begin working on battery enclosure to attach to the front portion of the folding main tube... these will be deep enough for 15S but I'm not sure if I can fit 2P on the frame and still have pedal clearance... time will tell.
This build is quick, dirty and Ghetto but it works and is using commonly available parts and a 9C style 20" rear hub (9x7 windings), 9FET Infineon, Torque Arms and Throttles / Brake Levers (believe it or not the kit brake levers felt better than the stock and had more of a two finger profile, better for a folding bike and my personal preference) from e-bikekit.com.
Daily power source for this eBike is currently a 15S10AH pack running 62.5v charged. Trick is for 1.0 I didn't bother to reprogram the controller. I wanted to test these 20" 9x7 for speed, torque and general rideability using the stock Infineon settings from e-bikekit.com (plenty of time for tweaking coming along soon enough). I even tested using their traditional LiFePo4 36v 10AH battery for comparison.
I have settled in at 62.5v and keep the 22A stock programming for now, I can reach a top speed on flats of approx 26-27 and have gotten as far as 29 on the downhills (before RPM increase wasn't motor RPM - currrent down to no load or less). The more impressive fact is this thing is like a little billy goat. I know with an additional 5-10amps it would just stand up all the time, it wants to pop a wheelie on hard accelleration already (weight distribution plays alot in this)... it climbs the worst hills around never dropping below 18mph.
When I say that these are NO Pedal findings, it's simple... my front sprocket is the stock (42 i think) and the rear is 18t BMX freewheel... I have a single speed which has a top pedal speed of 10-11mph. I couldn't help the top end on this or the torque @ 18mph if I tried because of my gearing limitations (more details, pictures and solutions later on).
I just shot a picture tonight of my 9FS with a child carriage attached to the rear swing arm (ugly attach, the bolts were rusted so it's zip ties and a sock to stop scratching the paint)... I had just returned from the 1.2mi round trip to my office where I had to transport 3 PCs and a few tool boxes (actually I have alot to move tonight) but the point is, battery (single 15S1P 5AH) is still going (has been all day) and shows nominal voltage. I have about 5 more trips and don't think it will last but it's half of my pack so... I have plenty of spare juice.
So far my only complaint with this eBike has been the weight which you do actually adapt to quickly and even with the added weight of the rear hub motor the thing still folds and can be carried with a single hand onto an Amtrak or Septa bus/train durring peak or off peak so ... mission accomplished.
I have basically fallen in love with it's cheap suspension which suprisingly to me, irons out the pot holes almost as well as my Specialized front shock (and the rear is smoother by far) on the road... off road, the 9FS sucks above 5 mph or so... Not a dual purpose eBike!
I use this now more than my faster Specialized because it's sleek, impressive looking, stealth (and that's before my frame tube mounting battery boxes in production) and just plain NEAT. People were already excited about my eBikes but now, even the ones who could care less for the eBike see this, think its perfect for them (I don't tell em it's an eBike until after they pick it up and remark, not too heavy) and then the revelation that's it an eBike and an offered test ride = Instant EVV Grin!
Pics, build issues, videos to follow.
-Mike
This is to document my latest build on a 2009.5 DownTube 9FS Folding Bike (http://www.downtube.com/Full_Suspension_Folding_Bike.html).
Version .01 Alpha
This is the 9FS without a sprocket/freewheel on the e-bikekit.com 9c rear motor. Note the LiFePo4 battery attached to a rear walmart clamp on rack - note the duct tape, this is Ghetta Fabulous. Also note the bags strapped to it as if it were a pack mule (bags contain: freewheel, replacement pull brake pads, misc replacement parts)
Version .02 Alpha
So now this is rideable but I must start calling it my Downtube FS or 1FS. Note the chain is now working but I have alot of truing to do on the rear wheel (this is not indicative of e-bikekit.com wheels but I took this from a fresh delivery off the truck so it hadn't been addressed by their staff for truing or tensioning, all customer orders are trued before shipping but I was in a hurry and said I would do it myself.) The Transit trunk bag holds 15S2P of LiPo but I only run a single 1P at a time while testing. This is still Ghetto and the brakes need work, the stock brakes may have been ok at 28lbs but by going to nearly 50lbs I have really pushed them past the working point - next upgrade is front disc brake then I will begin working on battery enclosure to attach to the front portion of the folding main tube... these will be deep enough for 15S but I'm not sure if I can fit 2P on the frame and still have pedal clearance... time will tell.
This build is quick, dirty and Ghetto but it works and is using commonly available parts and a 9C style 20" rear hub (9x7 windings), 9FET Infineon, Torque Arms and Throttles / Brake Levers (believe it or not the kit brake levers felt better than the stock and had more of a two finger profile, better for a folding bike and my personal preference) from e-bikekit.com.
Daily power source for this eBike is currently a 15S10AH pack running 62.5v charged. Trick is for 1.0 I didn't bother to reprogram the controller. I wanted to test these 20" 9x7 for speed, torque and general rideability using the stock Infineon settings from e-bikekit.com (plenty of time for tweaking coming along soon enough). I even tested using their traditional LiFePo4 36v 10AH battery for comparison.
I have settled in at 62.5v and keep the 22A stock programming for now, I can reach a top speed on flats of approx 26-27 and have gotten as far as 29 on the downhills (before RPM increase wasn't motor RPM - currrent down to no load or less). The more impressive fact is this thing is like a little billy goat. I know with an additional 5-10amps it would just stand up all the time, it wants to pop a wheelie on hard accelleration already (weight distribution plays alot in this)... it climbs the worst hills around never dropping below 18mph.
When I say that these are NO Pedal findings, it's simple... my front sprocket is the stock (42 i think) and the rear is 18t BMX freewheel... I have a single speed which has a top pedal speed of 10-11mph. I couldn't help the top end on this or the torque @ 18mph if I tried because of my gearing limitations (more details, pictures and solutions later on).
I just shot a picture tonight of my 9FS with a child carriage attached to the rear swing arm (ugly attach, the bolts were rusted so it's zip ties and a sock to stop scratching the paint)... I had just returned from the 1.2mi round trip to my office where I had to transport 3 PCs and a few tool boxes (actually I have alot to move tonight) but the point is, battery (single 15S1P 5AH) is still going (has been all day) and shows nominal voltage. I have about 5 more trips and don't think it will last but it's half of my pack so... I have plenty of spare juice.
So far my only complaint with this eBike has been the weight which you do actually adapt to quickly and even with the added weight of the rear hub motor the thing still folds and can be carried with a single hand onto an Amtrak or Septa bus/train durring peak or off peak so ... mission accomplished.
I have basically fallen in love with it's cheap suspension which suprisingly to me, irons out the pot holes almost as well as my Specialized front shock (and the rear is smoother by far) on the road... off road, the 9FS sucks above 5 mph or so... Not a dual purpose eBike!
I use this now more than my faster Specialized because it's sleek, impressive looking, stealth (and that's before my frame tube mounting battery boxes in production) and just plain NEAT. People were already excited about my eBikes but now, even the ones who could care less for the eBike see this, think its perfect for them (I don't tell em it's an eBike until after they pick it up and remark, not too heavy) and then the revelation that's it an eBike and an offered test ride = Instant EVV Grin!
Pics, build issues, videos to follow.
-Mike
