Going Electric

[jimw1960]

I just converted my old mountain bike to electric by adding a hub motor, controller, thumb throttle, and a 36v LiFePO4 battery. I want to use this for my 14-mile commute to work so I can get there without being all sweaty. My battery finnaly arrived from China last night (seems we don't make anything in the USA anymore, at least not cutting edge battery technology; the US invents the technology and China profits from it-- but I digress...). Anyway, I got it all put together today and took it for a test drive. It cruises at a fairly steady 15mph. I only pedaled on the steep hills. The battery wasn't fully charged yet but I still got 16 miles out of it before the low voltage cutout kicked in. That should be good for my commute. I can steal, er, borrow, electicity from work for my return trip. I figure it will cost 10 cents worth of electricity each way, compared to the gallon of gas it would cost for the round trip in my car. Anyway... all this got me thinking that it would be a whole lot cooler to make one of my old cruiser bikes into the electric commuter, instead of the mountain bike. So that go me thinking whether anyone on here had tried to go electric with their rat rods. Anyone here have any experience in this area.

Here is a pic of the mountain bike with the E-motor kit. Battery and controller are in the cargo carrier.

Here is a closeup of the battery/controller compartment. This would probably fit in a leather saddle bag on a rat cruiser.

 

[CCR]

ive thought about it but never pulled the trigger. if i did one id want a straightbar frame with a tank to hide the controller and batteries in or something like a huffy radio bike to hide the goodies. maybe people would think it had a drum brake on the front :mrgreen:

 

[ExtraBlaze]

There was a post a little while ago about this with a pretty sick bike in it.I'll see if I can find it.

 

[ExtraBlaze]

Here it is
viewtopic.php?f=6&t=4388&p=94564&hilit=electric#p94564.

 

[jimw1960]

Kewl. That gives me some ideas. That bike wont get to far on 2 dewalt 36v batteries, though. You need at least 6 dewalts to get any king of range.
--j

 

[HornetB]

This is what I have planned for my ride, turn my cruiser into an electric cruiser. I have a Felt El Guapo that I'm trying to turn into a reasonable option for getting to work on. It's a little heavy and slow with the one speed to ride to work, but I love the bike and riding it so a little extra help from a hub motor would be great. I want to do it as stealth as possible and keep with the original feel of the bike, so I got thinking and researching (Endless Sphere forum), and it's going to cost me some $$ but hopefully should remain cool.

One of the problems with a cruiser it that normally the easiest and cheapest option is to drop in a front hub motor. But my bike runs chopper style forks with no rim brake options, and few front hub motors have disc. With the extra weight of the motor and battery and increased speed I dont think it's wise to go without a front brake and rely solely on a rear coaster brake. So I'm pretty much forced to go for a rear motor and install something like a sturmey archer drum brake in the front, but now with a rear motor I lose the rear brake too. Luckily a few of the rear motors can take a disc so I'm going to opt for a geared rear hub motor with disc that I can later fit on, because of the weight of the bike and the fact it's only single speed I want a set up that can power the bike on it's own without pedaling if need be. I can get by with just the front brake until I get the rear sorted but it's been a lot of research working out what will work and what will provide me with the best answer. Because I'm running 3" tires I will also need to custom build the rear wheel with a wide rim and the motor.

I think for batteries I'm going to go for 6 Milwaukee v28 lithium manganese batts 2s3p for 56v and will mount them in some leather panniers low down or if I can work a stealthy option I'll mount them in the frame. So, I figure I'm not going to get out of this for less than $1000 but hopefully it will be a nice ride to cruiser around on with little pedalling effort on my part.

Let us know how you go with your cruiser Jim, I'll be watching.
HB

This will be the lucky recipient.

 

[Ratpick]

I'm all for some electric cycle action! It will be way cool with that Felt cruiser. That chopper fork would be perfect to weld disc brake mount onto. Have to rechrome though. Anyway, this is a perfect time to share a few pics of my friend Joe's "Electra". No pedal power, but the motors do plenty! This thing is sic! I finally rode it last week, and it's almost the acceleration of a regular motorcycle. These are old pics so it's come a little further since then, like adding a rear disc and starting on the aluminum side panels. I don't know too many details of it, but all from scratch...

 

[jimw1960]

Hey HornetB,
That will make a nice cruiser. Sounds like we are struggleing with the same dilemmas. One thing to keep in mind for the rear hub motor is that most of them are set up for 135mm dropout spacing to accomodate a freewheel gear cluster. Most cruisers have a narrower spacing for the rear dropouts. The endless-sphere forum is great and I have learned a lot from them. Check out the link to the youtube video below. I want to set up something like that; the saddle bags do a good job of hiding the battery and controller. That guy seems to be living with the coaster brakes only, but that isn't safe enough for me. So that leaves me to figure out how a way to fit a rim brake on a triple tree or springer front end. Send me an IM if you want to keep the discussion going. The guys on endless-sphere are great for technical electonics advice but they care not a wit about the rat-rod sense of style and aestheic.

http://www.youtube.com/watch?v=-YmgVcd_aAE

 

[socal_jack]

Some of the newer triple tree forks have disc brake tabs which would be way better than a rim brake, easy enough to get a disc hub. As far as the 135 mm spacing, the old cruisers are soft steel, I usually just spred the rear by hand, foot down on one side pullup on the other. Use a string from rear dropout around head tube to other rear dropout to make sure it's squared up. HAve done this for Nexus 7 installs on the old stuff. May have to square up the dropouts but this is easily done with a set of bolts.

HAve an prewar roadmaster I'm looking at electrifying with a hub motor.

 

[HornetB]

I dont mean to be moving away from the original topic but hopefully it's relevant for the original poster to glean info from.

Regarding the chopper fork, yep Choppersus has some chopper forks with disk tabs so that's a viable option for those wanting to drop in a front wheel with disk. I've heard some pretty good reports about the Sturmey XF-D drum brake, for me this has the added benefit of being pretty much a straight switch out with the current hub and wont require a new fork and will keep with the original look so I think I might still go that option unless I find very compelling evidence to say otherwise.

The rear drop outs on my frame are the standard 135mm drop outs so any std hub motor should fit, however few actually have a workable disc brake and I have no ability to install rim brakes on the rear unfortunately. The Bafang rear motor has the posibilty of disc so that's my number one contender. I think I will try the rear disc brake tab adapter from choppersus and see if that can get me a rear disc mount to use.

My biggest problem is that I might end up with only a fairly tall gear (which is good for when motoring, not so good when there is no electric power applied) because I have a wide 3" rear tire to clear. To get around this my bike currently uses an offset rear sproket, with a multispeed freewheel on the electric motor I'll likely end up in the tallest 2-3 gears. I dont think a single speed freewheel will work because of clearance issues but it will certainly be nice to have the freewheel option and I'm not a huge coaster brake fan.

Hopefully soon enough i can post some pics of the build. Cheers, HB

 

[daniel828]

I've been meaning to update some pics. of my bike. It actually is going thru another change with batteries as we speak.

Because I expierenced my own mini nuclear meltdown

No fire, just alot of smoke.
I bought some more batteries and this weekend I'm going to try a differnt approach.

 

[jimw1960]

Sheesh, Daniel! Looks like you need a beefier battery that will keep up with the power demands of that demon of a bike. Have you checked out the endless-sphere.com forums? Those folks can tell you everything you ever wanted to know about ebike batteries. That will really be a sweet ride when you get a good battery system on it. Are you going to paint it?

 

[HornetB]

That's a sweet bike Daniel. Love it. Plenty of good usable space in the frame to mount batteries and I like the rack you've used. Bummer about the burnout.

Do you mind letting us know what batteries you used and why they had a thermal meltdown? Not rated to your current draw? Lipo batts? What batteries are you going to this time?

You wouldn't want those to let go in front of an officer or you'd get done for doing a burnout.

 

[daniel828]

Heres a video of it in action. Full throttle is only good for about 2 miles riding distance at 35-37 mph. If I pedal and use 1/4 throttle I can get 6-8 miles at 15-18 mph.
http://www.youtube.com/watch?v=toalxGlUT3s
The battery is 80 volts with 2.3 amps but a123 lithiums can deliver about 40 amps continuosly, and about 70 amps for a few seconds. There is enough power on tap but it doesn't last too long.
I'm redoing the batery pack with more a123 cells for more range.