Advice on building a custom off road bike.

harryS

Well-Known Member
#21
I did the 2WD for the fun of it, but it turned out not to be much fun riding a fatbike in snow w/o a snowmobile suit, and without a partner, there was alway the chance I would have a mishap and freeze to death in the woods, just 1/2 mile from McDonalds. I still have the motor with snow tire on a fatbike rim, but the fatbike is now rwd with summer tires.
 
#24
Would you say that 2wd is actually dangerous, or does it just take some getting used to? I did see those harnesses. But, I am not sure if I would use a harness, just splice the wires, or maybe enen control the front and rear with 2 separate throttles.
 
#25
Would you say that 2wd is actually dangerous, or does it just take some getting used to? I did see those harnesses. But, I am not sure if I would use a harness, just splice the wires, or maybe enen control the front and rear with 2 separate throttles.
I can't imagine bothering with two throttles. Sounds doable but in practice, I thought it sucked. Not enough hands to manage effectively. Splicing isn't always as simple or effective as it sounds.
 
#27
I didn't see the 2wd wiring post. But, if you could send me a link, it would save me the headache of trying to figure it out myself. The other option would be 1 throttle. But, also have a button to push when I need a 2wd boost, like on the straight sections.

I haven't actually bought a bike yet. I was going to pick up a used one from Craigslist. What should I look for in a bike?
 
#28
I didn't see the 2wd wiring post. But, if you could send me a link, it would save me the headache of trying to figure it out myself. The other option would be 1 throttle. But, also have a button to push when I need a 2wd boost, like on the straight sections.

I haven't actually bought a bike yet. I was going to pick up a used one from Craigslist. What should I look for in a bike?
For 2WD be certain to find a bike with a STEEL not suspension fork. The diagram is in another 2wd post here.
What is you intended purpose in building a 2wd? I and others will make better suggestions with more information.
 
#30
Long story short, I need a bike that can climb a very specific hill near my house, to enable me to get to my garden. I dont care about range or speed. I want use the Dewalt 20v batteries that I already own. I have a ton of them. 2 of the 20v (18v under load) batteries in series limits me to a 36 volt system. The biggest reasonably priced 36v geared hubs that I can find are only rated for 500 watts. If one of the 500 watt geared hubs on the rear can get me up the hill with little or no pedaling, I will leave it as is. If not, I would add a 2nd motor to the front for extra power getting up the hill.

Thanks for the link. I will study the diagram if / when that phase of the project comes along.
 
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harryS

Well-Known Member
#31
I want to use battery docks like this one: https://www.ebay.com/itm/1x-battery-adapter-for-DeWALT-20v-Max-18v-dock-power-connector-12-gauge-robotics/142979592702?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649 This will enable me to use the Dewalt chargers that I already own, and also be able to continue to use the Dewalt batteries on my power tools, when I'm not riding the bike. Wiring these 20v max (18v under load) batteries in series, I will have the option to go 18v, 36v, 54v... Since, nothing in the bike world seems to operate on 54v, 36v seems the way to go. I am confident that the larger dewalt batteries put out well over 20A.
I think you will need 4 of those adapters. Two to get a nominal 36V and two more to parallel up your packs. The ebikeling controller will draw 22A.

The current controller will run on either 36V or 48V. A nominal 48V battery is 54.6V peak. Three of your Dewalt packs in series will be 63V peak. That is the max ratings of the 63V capacitors inside the controller, and I would not try it. Not sure the LED display can handle it either.
 
#32
I’ll be using the Dewalt flex volt 6ah batteries in 20 volt mode. In 20 volt mode, they have 3 sets of cells paralleled internally. I would think that these batteries could output 22+ amps without even breaking a sweat. That is unless they have an internal breaker or electronic current limiter that I don’t know about. I will contact the battery dock manufacturer to see what he knows about it. If I have to, I will go with a 4 battery/dock setup. But, I am hoping to not have to go that route.
 
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