Crystalite Double tap Questions
Hello. I'm new to the forum and to EV bikes.
A few weeks ago I put together a Schwinn with a Rear Drive Crystalyte 4012/408 double tap on a 700c running 48v. Its an Amazing motor!
But I have a couple problems with the setup. First it the battery mount. Its heavy duty aluminum, but after 200 miles, its toast. the sides collaps under the weight of the battery if I travel down rough roads, or sidewalks, and even short trips across soccer fields or unpaved footpaths will cause it to drop down onto the back wheel. Has anyone experianced this, or found a solution?
I'm also searching for a solution for the selector switch between the motor modes. In order to avoid law enforcement entanglements (its legal, but being pulled over is a nusance) I have the conroller and wires esentualy hidden on the carrier with the battery. That means reaching behind me, a few inches from the tire, and feeling for the switch. Anyone have an idea for a remot way to activate this switch?
For the batteries, I recommend a basket. I bought my kit from ElectricRider.com and they shipped the batteries in a big nylon pack along with a basket the pack is supposed to be placed in. It works very well so far. Scroll down to the very bottom of this page to see a picture.
By the way, "heavy-duty aluminum" is an oxymoron.
Have you seen the XtraCycle gizmo? I have one Stretch bicycle ... the biggest cargo I carry with it is groceries, and it holds four bags of them real fine.
As for holding batteries, have you thought about ones that have a higher density of power per pound of battery? Such as NiMH or Lithium...? On the stretch bicycle I'm using a pair of DeWalt packs (33 volt 4.6 AH). They're so completely light it's not funny.
- David Herron, http://davidherron.com/
If you buy four Dewalt 36 volt batteries off ebay you could put together two 72 volt packs that weigh practically nothing and charge up in 30-40 minutes. I am planning to upgrade to 72 volts using the same motor (4012/408) as you and would love to hear your opinions on your set up. I would also like to know of a good place to buy the motor and controller.
I was hoping you would get back to me. As part of my upgrade from my 36/33 volt rig, I was going to add two more Dewalt packs for a total of six. The four Dewalt packs I have been using had much more range than the three 8 amp-hour (total of 384 watt-hour) lead acids I was using even though, in theory, they have less watt hours. I think it is because the voltage stays so flat for 90% of the discharge cycle whereas the voltage dropped with the lead acids and the bike just got slower and slower. Lugging the extra weight around probably hurt the range as well. The lead acids gave me more power at first but less range. The Dewalts are less powerful but put the same power out for the whole ride.
So, I will be using six Dewalt packs, at about 66 volts. That should be plenty of power and range for me, especially if I don't abuse the acceleration and speed thing. I was thinking of a rear drive also and also have 700c wheels. I was advised that a 20 amp controller may burn out because at 66 volts I might exceed 20 amps on occasion and that I should get a 2.9 pound 35 amp controller. I was told that a 20 amp fuse would not be fast enough to protect the diodes in the cotroller. Your thoughts?
Did you get any ideas for hiding your switch? Seems to me you can just move it to a discreet place up front.
How does the 408 feel on hills?
Are you using a 20 amp controller?
If so, which controller is it and did you get it from the same place as your wheels?
Do you know your max amperage when accelerating from full stop?
The following is an email I got from a guy on this subject:
DATE TIME V(start) V(end)
11/17/06 11m 13s 67.9 65.8
11/18/06 17m 23s 69.8 65.1
11/20/06 18m 11s 71.0 64.6
11/21/06 16m 11s 69.0 54.5
AHrs Sp(max) Sp(ave)
0.899 25.4/40.9 14.5/23.4
1.300 26.3/42.4 15.3/24.6
1.690 26.8/43.3 16.2/26.1
2.220 28.7/46.3 17.6/28.4
Distance WHrs WHrs/ A(max)
2.73/4.39 55.6 20.4/12.7 24.1
4.60/7.38 85.5 18.6/12.0
4.90/7.91 102.7 20.9/13.0 24.0
4.90/7.91 128.3 26.1/16.2 24.6
There are probably a few rounding errors on some of these numbers but I don't believe any of them are too far off.
The good news. It appears that I am able to make a five or six mile run with no problems as long as I don't overstress the packs.
Sounds like I'd better go with the 35 amp. Also, your batteries are close to 60 volts when first charged. That is not too far off from what mine will be. You don't sound too impressed with the hill climbing of the 408. Do you see a big difference between the two motors on level ground?
I built a stick-shift that runs along the center part of the bike. It starts in the rear where it connects with the controller and goes up to the handlebars.
If you cut it right (just past the stem of the bike), you can easily turn the bike - and reach down and shift from the 408 to the 4012 - and visa versa.
Here's a picture of it.
I'd post a video of it in action, but I've decided to just use the 408 portion, in combination with a 35 amp controller with some of those new sweet 36 volt Dewalt batteries.
Anyway, here's a quick series of photos that show how I mounted and waterproofed the controller (live in Seattle), and then hooked the stick-shift to it. Sorry for the ones that are blurry, but it should still get the idea across.
1st, grab some aluminum sheeting like used for ducts, etc from Lowe's. $3.00 or so is what it cost me. I used aluminum so that it could easily conduct heat - yet provide additional protection.
Also grab some foil tape (high temperature) so that you can easily arrange the shape.
2nd, get the shape right.
3rd, insert the controller into your formed aluminum and screw it to the bottom of the xtracycle board. (I actually put a separate board under the xtracycle platform so that I could turn the controller sideways.)
4th, after painting the dowel black (or whatever color that matches your bike), then drill a hole that will fit the toggle switch on the controller. You want it to just fit. I also found that there are some cheap toggle rubber covers you can buy at Lowe's in the electrical section.
5th, cut a small 'guide'. This you'll attach directly next to the dowel that's fitted over the toggle. Close enough to keep the dowel from popping off, but far enough away so that it won't keep the dowel from sliding back and forth.
And here it is attached:
6th and finally, fabric stores sell neoprene or at least water-resistant material. Cut it and use it to cover the holes on the sides of the tube.
It worked really, really well, and since the whole bike was black and silver, you really couldn't tell that the shifter was there (the upclose shots with flash made it look more obvious than it was).
Question , how do you hookup up the dewalt batteries and not drain the batteries too far?