Building a new electric assist bike
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Building a new electric assist bike
I don't often hang out here with the electrified crowd, but I'm currently working on a project that I would appreciate some feedback on.
About 5 years ago, I did a Wilderness energy electric conversion for my wife. At the time, I bought two kits, thinking I'd sell one in my shop.
It never sold however, so I still have it.
Anyway, the bike I converted for her is a 700c wheel bike, and although the motor has worked beautifully with no issues whatsoever, she is now finding the bike to be very cumbersome.
I decided to dig out the spare kit, and build her a new bike from the ground up, this time, a 26" wheel bike with slacker frame angles, and an internal gearhub drivetrain.
I'm documenting the build as I go on Youtube, here's what I've done so far.
About 5 years ago, I did a Wilderness energy electric conversion for my wife. At the time, I bought two kits, thinking I'd sell one in my shop.
It never sold however, so I still have it.
Anyway, the bike I converted for her is a 700c wheel bike, and although the motor has worked beautifully with no issues whatsoever, she is now finding the bike to be very cumbersome.
I decided to dig out the spare kit, and build her a new bike from the ground up, this time, a 26" wheel bike with slacker frame angles, and an internal gearhub drivetrain.
I'm documenting the build as I go on Youtube, here's what I've done so far.
Last edited by Dan Burkhart; 06-26-16 at 07:41 AM. Reason: edited so the videos would show
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Well thanks again. Got the rear wheel laced, so it's up for tensioning and truing in the morning. Should be part of the series tomorrow.
Having people watch your progress is a real motivator. This whole Youtube thing is pretty new to me, so I'm just having fun with it.
Having people watch your progress is a real motivator. This whole Youtube thing is pretty new to me, so I'm just having fun with it.
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OK, here's where I'm wading out of my depth.
As I explained in one of the earlier videos, I am discarding the brake lever with the kill switch built in, and wiring a separate kill switch on the handlebars. The reason being, the lever is junk, but it does seem a good idea to to be able to cut the power in case it stuck on.
I was simply going to wire an on off switch in place of the lever, but was surprised to learn that pulling the lever actually closes the circuit rather than opening it. This means that the safety overide actually relies on a power supply rather than cutting power. Hardly seems fail safe to me.
So, I went with the original plan, and connected the cable to bypass the key switch instead as I had done on the earlier conversion.
Is it common to have safety overides that function by supplying power, and if so, why?
I was simply going to wire an on off switch in place of the lever, but was surprised to learn that pulling the lever actually closes the circuit rather than opening it. This means that the safety overide actually relies on a power supply rather than cutting power. Hardly seems fail safe to me.
So, I went with the original plan, and connected the cable to bypass the key switch instead as I had done on the earlier conversion.
Is it common to have safety overides that function by supplying power, and if so, why?
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TADA!
Still a few minor touches to look after, but it's ready to present to my wife when she gets home from work.
I took it around the block a few times. Works great, lots of power, super quiet, and the Sturmey Archer just plain works as expected.
Still a few minor touches to look after, but it's ready to present to my wife when she gets home from work.
I took it around the block a few times. Works great, lots of power, super quiet, and the Sturmey Archer just plain works as expected.
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Project complete.
First real test ride is in the books. Everything seems to work as it's supposed to. I had to stop mid ride to give the Sturmey Archer hub shifter a bit of an adjustment, but that's to be expected first time out till the cable housings settle into place.
I noticed a bit of a vibration from the front fender on accelleration, and at lower speeds while under power. It is much more noticeable on the video. I guess the camera mike is more sensitive than my ears.
Anyhow, it appears that is the only issue left to deal with. It remains to be seen what kind of range it will get. I'm on the road now for the next week, so hopefully when I get back, I can take my wife to a trail somewhere to give it a good shakedown.
I noticed a bit of a vibration from the front fender on accelleration, and at lower speeds while under power. It is much more noticeable on the video. I guess the camera mike is more sensitive than my ears.
Anyhow, it appears that is the only issue left to deal with. It remains to be seen what kind of range it will get. I'm on the road now for the next week, so hopefully when I get back, I can take my wife to a trail somewhere to give it a good shakedown.
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Thank you. I guess the true gauge of success will be if my wife actually likes it when she finally gets around to riding it.
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Torque Arm?
Dan, I don't know if you said so in your videos but hopefully that's a steel fork and has a torque arm of some sort.
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It is a steel fork. Video #2 shows how I fabricated safety tabs to engage the axle flats and re-enforce the dropouts. Works as a torque arm.
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Very good! Just checking cuz torque arms are a must for long term safety.
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The bike I converted 5 years ago has the same safety tabs I put on this one, and the dropouts show no sign of stress, so I'm pretty confident they do their job.
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Bit of an aside.Very nice job! But
This doesn't really look like an average DIY could assemble this bike.
You are obviously a pretty adept mechanic-and a handy fabricator.
Your "torque are equivalents" fabrication-drilling hand filing cutting out getting the little steel plates-not typical DIY stuff.
Are any of the front wheel kits out there really bolt on safe?
I'm getting older almost 61 and I'm considering using a 1994 vintage Trek 950 as an electric assist bike to get me the 5 miles-one way-to the various sub teaching jobs I do.I have an ancient used 98 Suburban-gets 15 mpg in careful city driving(broke so new car not in cards).
I wonder if these kits are really peak speed 12mph to 18-20 mph-drop trip to under 20 minutes.
Sorry for the big aside
Thanks
Charlie
This doesn't really look like an average DIY could assemble this bike.
You are obviously a pretty adept mechanic-and a handy fabricator.
Your "torque are equivalents" fabrication-drilling hand filing cutting out getting the little steel plates-not typical DIY stuff.
Are any of the front wheel kits out there really bolt on safe?
I'm getting older almost 61 and I'm considering using a 1994 vintage Trek 950 as an electric assist bike to get me the 5 miles-one way-to the various sub teaching jobs I do.I have an ancient used 98 Suburban-gets 15 mpg in careful city driving(broke so new car not in cards).
I wonder if these kits are really peak speed 12mph to 18-20 mph-drop trip to under 20 minutes.
Sorry for the big aside
Thanks
Charlie
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Hello, we are writing about electric bikes in our website https://www.e-bisiklet-dunyasi.com and i was thinking to write about converting a bike to an alactric bike. So i would like to ask if you would mind to use the vids of yours. And by the way you had a great job really. Cause usually people just convert the bikes with ready sets.
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Are any of the front wheel kits out there really bolt on safe?
I'm getting older almost 61 and I'm considering using a 1994 vintage Trek 950 as an electric assist bike to get me the 5 miles-one way-to the various sub teaching jobs I do.I have an ancient used 98 Suburban-gets 15 mpg in careful city driving(broke so new car not in cards).
I wonder if these kits are really peak speed 12mph to 18-20 mph-drop trip to under 20 minutes.
Sorry for the big aside
Thanks
Charlie
I'm getting older almost 61 and I'm considering using a 1994 vintage Trek 950 as an electric assist bike to get me the 5 miles-one way-to the various sub teaching jobs I do.I have an ancient used 98 Suburban-gets 15 mpg in careful city driving(broke so new car not in cards).
I wonder if these kits are really peak speed 12mph to 18-20 mph-drop trip to under 20 minutes.
Sorry for the big aside
Thanks
Charlie
Last edited by jayhawk12; 01-12-12 at 06:47 AM. Reason: sp
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Thank you. This is very informative. I am thinking to upgrade my bicycle because new are so expensive, but now I am finding parts are out of mind too. Can someone point a cheap web site for the parts? I will certainly not pay $30 for cable or $300 for battery...
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Update
Well, the bike has been in use for almost a year and performing flawlessly. At some point, I'd like to upgrade the battery pack, but the SLA pack works OK for rides up to 30 km or so.
The only change I've made is to upgrade the brake pads to Kool Stop Dual Compound ATB pads. Braking performance went from marginal to very good.
The only change I've made is to upgrade the brake pads to Kool Stop Dual Compound ATB pads. Braking performance went from marginal to very good.

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Thanks for the update. What battery did you use? Specs = top speed, range, weight etc?
Danke
Danke
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Top speed, on the level, no wind, about 20 kmh.
Last edited by Dan Burkhart; 04-27-13 at 08:56 AM.