Razor MX1000 electric "BMX" :P

[16v4nrbrgr]

I have the big dirt wheels but wanted to test on these scooter wheels since they're kinder on the motors because like you said, revs. I also wanted to see how hard it kicks before putting the power through a Sturmey 3 speed, might run without caps when at full charge on those because its quite powerful now.

It's hilarious how this bike even just freewheeling by people with their horses trying not to spook them, the horses are still soul shocked by it. Its like they see it as a robotic horse coming to take their job so they get turned into dog food and elmer's.

 

[paul]

nothing more fun then being in the woods and a big hill with 20 year olds walking their bikes up the hill because they ran out of strength and pedaling past them (electric motor assist of course which they don't know). all they see is an old over weight man make them look weak pedaling past them with a a big grin on his face

 

[16v4nrbrgr]

For me with this bike I'll go zooming past cyclists only later to be found pushing the bike uphill because I ran out of juice or need to save it for a fun part. Hopefully that's not the case here anymore, lol! I think with the chain tighter the bike will get even better efficiency than today. It was really sloppy by the end.

 

[16v4nrbrgr]

I scared myself going uphill the first time today, this thing is really amazing now! It's totally like a pocket bike, and just leaped up 800 ft of elevations around corners and 30 percent grades without the motors getting hot, or even lukewarm for that matter! Every corner offers the possibility to drift or wheelie out now! Had a couple sketchy check ups on the brakes too because my arrival speeds were high.

If I can figure out a way of taking a video without looking like a huge tool I'll do it.

 

[maurtis]

Nice, that twin motor setup looks intriguing. I love the work you did on this build!

 

[16v4nrbrgr]

Thank you Maurtis

Passed a car accelerating going uphill today, no sweat! Every time it takes off the front wheel comes off the ground, lol. The only unfortunate fact is that having 2 motors halves the range, so now it's a five mile bike. I'm still getting up the nerve to try the Lipo pack, maybe this week since I now have a charging port.

If I lived anywhere but here I'd gear it for 30-35 mph but it's massively hilly here so I need the lowest sprocket I can find for the motard wheels at 90T. With the lack of selectable gears, the motard set is like being constantly in 2nd gear on the Sturmey wheelset. Maybe it's for the better, since its so fast and selecting gears is kinda tricky, and there's the simplicity.

 

[16v4nrbrgr]

Yesterday I found that my capacitors weren't working in the afternoon when I took a ride. I have tracked it down to a bad supercapacitor, the left side one, which seems to have a bad connection inside because it won't charge at all. I'm sure there's stranded copper leads inside to the jelly roll and they wore out because I can hear the roll moving around inside like it got dislodged.

I took the capacitors off the bike and hooked up the resistor and headlight circuit for use as a headlight in the meanwhile. I might fix this one if its possible, or have it re-manufactured, or possibly just buy another for $50.

One thing that sucks about this bike right now is the short range, so I might just save up for a fancy battery pack instead.

 

[16v4nrbrgr]

I was told by the Authoritie that my electric bike looked like a "whole ton of illegal fun", and that I needed turn signals, so here they are, turn signals and brake light, headlight and running lights, all operational, this thing's like a chrismas tree, lol. It also has a mad annoying horn that beeps when the signals light up if selected.

 

[16v4nrbrgr]

This weekend I'll be working on the eMotard a bit, I plan on checking the dual motor cradle for cracks, and repairing it if necessary. I'll note any weak spots and build in reinforcement for the next iteration, which I plan on building using the R&D from this first motor cradle.

If anyone would like a TIG welded aluminum motor cradle for their Razor MX500/650 which will hold two Currie 500-1000w motors, let me know and I will build you one. I designed it so that it bolts into the stock swingarm with this in mind, so others can experience this if they want my help. This bike really is something else, it accelerates like a street bike, and if you settle for more gas-bike-like acceleration and less 30% grade climbing, they can easily be geared for 45-50mph, the twin Curries are like a turbine of torque!

I need to find a good deal on a spare Sturmey hub so I can set the bike up with my geared knobbies for the summer trail running. Money is tight right now so I'll wait and keep these scooter wheels on because they are reliable and fun on pavement while I sort out my pavement gas bike to ride.

 

[16v4nrbrgr]

On a post office run today, on the way back I decided to hit up this awesome hill with hairpins by by house uphill, and had it stall out. I heard a spark from a familiar location of issues; the main power connection to the controller.

It seems that the standard Monster/TNC/Razor two spade connectors cannot handle this task, and the connection quality breaks down, and then the connectors get hot and start migrating toward each other in molten plastic, then short out.

The solution is simply large 8 gauge spade connectors routed separately. The Scooter connectors move around too much, and even though they are copper plated, they still maneage to generate enough resistance to get too hot, this is the second time this has happened, the first time I thought it was a fluke, but no, it's not lol.

I think at 48v and below, it would be alright, but considering at 60v with this combo it will pull in excess of 100A, any bad connections will get hot and melt down.

 

[16v4nrbrgr]

Oh wow, it is fixed alright! Warm weather makes these old school agm batteries work really well!!

After 3.7 miles of riding, almost being hit by 3 cars, and the new speed of it + the hot tire grip, I was wore out, it prolly has 6 miles in it today but I can't I'm pooped!

 

[16v4nrbrgr]

I haven't had the time or energy to ride in quite a while but I took my bike out for a couple rides today, it was awesome! I took it out to the post office for a short ride to cycle the batteries which have been sitting for months at full charge, and then attempted to charge it again, when I plugged it in the charger shot out a spark, and crapped out! lol

I quickly found out what was wrong when the AC power cable to the charger fell out, guess I tugged the cable too many times, and the wires fatigued. A couple blobs of solder and its back to working fine again, I'm glad since the 60v charger is a $50 item.

The second ride was pure bliss, but a bit shorter than normal because it was getting cold and the batteries need a couple cycles to desulfate since it's been sitting. I estimate that the ride was about four miles til it started slowing down. It'll be better after the next charge, and the next, the AGM batts work better when you cycle them often. Someday when I've got about $600 I'm going to replace the AGM batts with some top of the line LifePO4's or NiCads that will double or triple the range and make the bike less of a thrill toy/pit bike and more of a practical vehicle.

 

[paul]

also it will make your motorized bicycle a lot lighter. good batteries to me make a huge difference but as you said they are expensive to say the least

 

[16v4nrbrgr]

Yeah I priced it out, to cut the battery weight by half at the current capacity it would cost 4-5x what I pay for the AGM battery pack which is $100 from Chrome Battery Company. If I wanted to double the capacity to 20AH and maybe get 15 miles per charge max, the pack would be nearly a grand if I use the SLA direct replacements with integrated battery management. I could buy individual cells or pouch batteries and build my own battery system and save a couple hundred, which is what I might do since it would be easier to make a pack that fits inside the plastics completely. I'm waiting to see if the prices drop or a new chemistry is manufactured which is more power dense than LiFePO4, but doesn't need careful monitoring like the powerful Lithium Polymer RC batteries. The thing I like about the lead batteries is that they just work, and a replacement pack every year and a half or so is cheap and the peak discharge performance comes back. I'm a bit skeptical about dropping $500+ into a pack which my bike might fry from big current flow or a charging error. I'm pretty content with the AGM batteries for performance, even though the range is limited, because this bike has so much low end torque that it leaves me worked over after only a 5 mile ride, and the rear tire is getting bald from all the drifting! lol

 

[16v4nrbrgr]

I'm putting it up for sale, it may take a while to find her a worthy home, this is no ordinary electric bike! I put a thread in the FS section with details and price.