Alright I posted about a year ago asking for some advice and I've been tinkering away ever since. After much trial and error, I have created something that I don't feel ashamed to post here among the other awesome bikes that read about all the time.
I started with a walmart hardtail with a yescomusa kit, 2 6s lipos and a lipo charger. The very second that bike moved me forward with electric power I was hooked. That setup got me to 30mph with a slight hill. I eventually purchased a 9 fet lyen controller set at 30 amps and two more lipos for a 10Ah pack. Imagine my excitement when I plugged 3 in series and found out I could go even faster
The bike had its share of issues though. The brakes and forks were no good and I wanted a full suspension bike so I picked up a v2100 and starting piecing a new bike together.
This is the current result:
It's a v2100 with a farfle swing arm. I got a cheap rear shock off of ebay to replace the stock spring. I put a fork on it that's at least better than the one it came with. The front brake is an avid bb7 with a 203mm rotor.
The motor is my trusty yescomusa hub that I started with. I drilled some holes in it for cooling, replaced the phase wires with three strands of 16 awg magnet wire for each phase and ran like 10 strands of 34 awg magnet for the halls and a temp sensor if I ever decide to install one. I sprayed the inside with some dielectric grease and it's been working great. If anyone needs help getting phase wires through the axle of this particular motor, I may have a few pointers.
The controller is a crystalyte 12 fet sensorless controller. I got it from ebikessf along with a CA v2.3 DP and the folks at ebikessf even programmed the correct rshunt value for the ca before shipping it out. Quite a pleasant surprise. I went with a sensorless controller because I figured it would be good to have one in my collection as a backup. I intend to get an 18 fet in the future.
The batteries are 6 6s 5Ah 15c zippy lipos configured in 18s2p. I know a lot of people use the higher C, at least 20c usually, but I am a starving college student so I went with the cheaper option. They seem to work fine. I have a cell log and a crappy battery medic (realized it was the bad version after I got it
) I also have a turnigy watt meter and a hobbyking lipo balance charger. The balance charger proved to be excruciatingly slow so I now have a bc168 on the way. For day to day charging I have two adjustable power supplies in series. They both put out between 32-40v so I have them adjusted to 74v. They each put out 350w so roughly 700w total charging power. Bulk charging is great I think it is safer because it is easier to be present for an entire 30-60 minute charging session as opposed to leaving lipos attached to an rc charger for hours on end. I'll be honest, when I was using the balance charger I just left the batteries unattended because I couldn't sit in my garage for six hours out of the day. I check my cells religiously and I've had to decommission two batteries for a bad cell so far.
This was also my first wheel building endeavor. I laced the yescom hub into a rhyno lite 24 inch rim with a single cross pattern. Took a few minutes to wrap my brain around it but I thought it was very easy.
Before I installed the farfle swing arm, I went through all the stages of torque arm development. First no torque arm, but the dropouts started to spread a little, so no good. Then, 10mm wrench with hose clamps. One on each side. This worked for about 50mi before one hose clamp snapped during a ride. I then formulated a real solution: dogman style torque arms. Picked up an angle grinder from harbor freight and and piece of angled steel and some bolts. Took me about an hour or two of screwing around to get a good clamping torque arm on each side.
But a few days after finishing my torque arms I found a farfle swingarm for sale in the for sale section which I instinctively purchased because I have literally dreamed of owning one.
The bike is obviously not complete yet. I need to come up with a more elegant solution for mounting the batteries and controller. Currently, I have the batteries firmly taped to these steel plates with strapping tape, but this is only good for testing because it doesn't physically protect the batteries. Won't be too hard to attach some hard cases or something like that though.
After I finalize this setup, I will probably ride it around for a few months before making any major changes. The sensorless controller is nice to have, and certainly usable as a day to day controller, but it definitely is not a replacement for a sensored controller. After I hit about 30mph, I get a stuttering effect unless I am very careful with the throttle. I think the stuttering effect puts a lot stress on the dropouts. I observed that the better my torque arms got, the less of a stuttering effect I would have, but not even the farfle swing arm eliminated the problem completely. No matter what I get the stuttering at around 30mph but it seems to be common with sensorless controllers.
I am completely open to comments and criticism. I want to refine this bike as I become more experienced. Ultimately, I'd like to have a cromotor, 18fet controller and a fancy dual crown fork on this bike, but I feel I have some learning to do yet before I take that plunge. I also want to take the MSF it is free in PA but I don't have the time to do that quite yet. Probably 90% of my research for this bike came from the endless sphere and I'd probably have killed myself by now if I hadn't spent so much time reading and rereading the major build threads on this forum. I'll continue to update this thread with my progress and I'm happy to answer any questions.
I started with a walmart hardtail with a yescomusa kit, 2 6s lipos and a lipo charger. The very second that bike moved me forward with electric power I was hooked. That setup got me to 30mph with a slight hill. I eventually purchased a 9 fet lyen controller set at 30 amps and two more lipos for a 10Ah pack. Imagine my excitement when I plugged 3 in series and found out I could go even faster
The bike had its share of issues though. The brakes and forks were no good and I wanted a full suspension bike so I picked up a v2100 and starting piecing a new bike together.This is the current result:
It's a v2100 with a farfle swing arm. I got a cheap rear shock off of ebay to replace the stock spring. I put a fork on it that's at least better than the one it came with. The front brake is an avid bb7 with a 203mm rotor.
The motor is my trusty yescomusa hub that I started with. I drilled some holes in it for cooling, replaced the phase wires with three strands of 16 awg magnet wire for each phase and ran like 10 strands of 34 awg magnet for the halls and a temp sensor if I ever decide to install one. I sprayed the inside with some dielectric grease and it's been working great. If anyone needs help getting phase wires through the axle of this particular motor, I may have a few pointers.
The controller is a crystalyte 12 fet sensorless controller. I got it from ebikessf along with a CA v2.3 DP and the folks at ebikessf even programmed the correct rshunt value for the ca before shipping it out. Quite a pleasant surprise. I went with a sensorless controller because I figured it would be good to have one in my collection as a backup. I intend to get an 18 fet in the future.
The batteries are 6 6s 5Ah 15c zippy lipos configured in 18s2p. I know a lot of people use the higher C, at least 20c usually, but I am a starving college student so I went with the cheaper option. They seem to work fine. I have a cell log and a crappy battery medic (realized it was the bad version after I got it
) I also have a turnigy watt meter and a hobbyking lipo balance charger. The balance charger proved to be excruciatingly slow so I now have a bc168 on the way. For day to day charging I have two adjustable power supplies in series. They both put out between 32-40v so I have them adjusted to 74v. They each put out 350w so roughly 700w total charging power. Bulk charging is great I think it is safer because it is easier to be present for an entire 30-60 minute charging session as opposed to leaving lipos attached to an rc charger for hours on end. I'll be honest, when I was using the balance charger I just left the batteries unattended because I couldn't sit in my garage for six hours out of the day. I check my cells religiously and I've had to decommission two batteries for a bad cell so far. This was also my first wheel building endeavor. I laced the yescom hub into a rhyno lite 24 inch rim with a single cross pattern. Took a few minutes to wrap my brain around it but I thought it was very easy.
Before I installed the farfle swing arm, I went through all the stages of torque arm development. First no torque arm, but the dropouts started to spread a little, so no good. Then, 10mm wrench with hose clamps. One on each side. This worked for about 50mi before one hose clamp snapped during a ride. I then formulated a real solution: dogman style torque arms. Picked up an angle grinder from harbor freight and and piece of angled steel and some bolts. Took me about an hour or two of screwing around to get a good clamping torque arm on each side.
But a few days after finishing my torque arms I found a farfle swingarm for sale in the for sale section which I instinctively purchased because I have literally dreamed of owning one.
The bike is obviously not complete yet. I need to come up with a more elegant solution for mounting the batteries and controller. Currently, I have the batteries firmly taped to these steel plates with strapping tape, but this is only good for testing because it doesn't physically protect the batteries. Won't be too hard to attach some hard cases or something like that though.
After I finalize this setup, I will probably ride it around for a few months before making any major changes. The sensorless controller is nice to have, and certainly usable as a day to day controller, but it definitely is not a replacement for a sensored controller. After I hit about 30mph, I get a stuttering effect unless I am very careful with the throttle. I think the stuttering effect puts a lot stress on the dropouts. I observed that the better my torque arms got, the less of a stuttering effect I would have, but not even the farfle swing arm eliminated the problem completely. No matter what I get the stuttering at around 30mph but it seems to be common with sensorless controllers.
I am completely open to comments and criticism. I want to refine this bike as I become more experienced. Ultimately, I'd like to have a cromotor, 18fet controller and a fancy dual crown fork on this bike, but I feel I have some learning to do yet before I take that plunge. I also want to take the MSF it is free in PA but I don't have the time to do that quite yet. Probably 90% of my research for this bike came from the endless sphere and I'd probably have killed myself by now if I hadn't spent so much time reading and rereading the major build threads on this forum. I'll continue to update this thread with my progress and I'm happy to answer any questions.
