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RC-Monster Mike · 06:03 PM

Got the modules installed last night and went for a night run! WOW what a difference the lipo conversion made. First ran at 66% current limit(200 amps) then in full power mode(300 amps at 74 volts in theory, though in unlimited mode it bursts higher amps). Full power mode is downright scary - I seriously am in need of a better throttle(only 90 degrees of twist makes for a twitchy ride) - I would like to get a 120 degree throttle to add some resolution for sure. The gearing tops it out at around 43mph and it gets there in a hurry! At 25, if you grab full throttle, it will throw you off the back unless you let up quickly - feels like a kx250 when it hits the powerband! I dialed in a progressive curve and went back to 80% current limit(240 amps) - theoretically limiting the power to around 20HP, which is plenty for a 150lb machine. I am totally psyched!
Oh...before i dialed back the power, i managed to rip the primary drive belt in two(hanging off the foot peg). I hope to get some body panels done this week to cover the batts/wiring a bit. Here is a picture:

RC-Monster Mike · **pictures -** 10.04.2011, 06:01 PM

the bike and the broken belt

crazyjr · 10.05.2011, 03:03 AM

Quote:

Originally Posted by RC-Monster Mike

the bike and the broken belt

Hey mike, nice bike. What is the range on the stock bike? What is the expected range on your battery conversion? I love that you used basically off the shelf batteries, makes fixing and replacing components easier. If i ever lose enough weight, i'd like to get a E-bike for commuting to work. I would look into this setup, as i know the guy doing it is one of the best in the area of engineering and ergonomic and wouldn't sell anything that either doesn't work , or he wouldn't use or ride himself.

One thing please, If you do get into the E-bike area, please don't let it overtake the rc part. Would suck if RC-Monster didn't do RC parts anymore

BrianG · 09:48 AM

Quote:

Originally Posted by RC-Monster Mike

It has a 0-5k pot throttle(Magura twist - very common). I would love a better throttle, but aside from building one there doesn't seem to be many other options. IMO, 90 degrees is a bit stingy - I have at least this much on every gas bike I own, but with 5 or 6 speeds, the actual "speed resolution" is 5 or 6 times better. Certainly 120 degrees of twist would help, as would an exponential throttle - they just don't exist or I don't know where to get one.

Unfortunately, I don't know enough about how all these throttles are built to offer good suggestions. A pot is simply a wiper arm that scrapes across a resistor giving variable values at the wiper arm contact, so it should have virtually infinite resolution. I wonder if the controller is your limiting factor? It might apply steps of output based on different resistance input thresholds (basically a really low-resolution A-D converter

). Simple testing with a meter at the throttle output should tell you what it's doing, but testing the output of a BL controller to see what its resolution is is a bit more difficult to measure. If it IS a matter of 60* twist not having enough resolution, maybe retrofit a different 5k pot in there? I would be careful about reliability though as the mechanical action of that wiper arm "scraping" does cause wear and "noisy" actuation. I'm kinda surprised digital encoders aren't used to avoid that.

Quote:

Originally Posted by crazyjr

...One thing please, If you do get into the E-bike area, please don't let it overtake the rc part. Would suck if RC-Monster didn't do RC parts anymore

While I agree with you, it is obvious more and more manufacturers are coming out with off-the-shelf electric products, so the custom side of things has to be taking a hit. It's not like the old days where if you wanted an electric toy, you basically had to build it. I think maintaining current custom items is nice for those who still like to tinker, but I can see Mike having to diversify to make enough green to keep the lights on.

rchippie · 12:30 PM

Quote:

Originally Posted by RC-Monster Mike

the bike and the broken belt

Mike that looks AWSOME.

mistercrash · 01:20 PM

Those modules look awesome, very clean look. ''Looks factory'' like Chip Foose says. The whole bike is pretty darn sweet.

Now I'm having a hard time figuring this out. I presently run on 48V 34 amp SLAs. To get to close to the 48V mark with lipos, do I need to go with 12 or 13 cells? 3.7V nominal times 12 = 44.4V or 3.7V nominal times 13 = 48.1V. Which one is it? If 12 cells is the number I need it seems a lot easier to configure, I would need 12 6S 5000 mah packs total. I would probably try Turnigy packs at first (not the Nanotechs) as I don't think I can convince my wife of letting me spend almost $1700 for Hyperions. Turnigys 40C would be under $900 including shipping.

Man I am also having trouble wrapping my brain around the fact that I could get better power and range from just two battery modules with less than half of the volume and weight of my SLAs.

RC-Monster Mike · 10.05.2011, 01:34 PM

Quote:

Originally Posted by mistercrash

Those modules look awesome, very clean look. ''Looks factory'' like Chip Foose says. The whole bike is pretty darn sweet.

Now I'm having a hard time figuring this out. I presently run on 48V 34 amp SLAs. To get to close to the 48V mark with lipos, do I need to go with 12 or 13 cells? 3.7V nominal times 12 = 44.4V or 3.7V nominal times 13 = 48.1V. Which one is it? If 12 cells is the number I need it seems a lot easier to configure, I would need 12 6S 5000 mah packs total. I would probably try Turnigy packs at first (not the Nanotechs) as I don't think I can convince my wife of letting me spend almost $1700 for Hyperions. Turnigys 40C would be under $900 including shipping.

Man I am also having trouble wrapping my brain around the fact that I could get better power and range from just two battery modules with less than half of the volume and weight of my SLAs.

34AH SLA batteries would be a rough equivilent to 17AH in Lipos - Lead batterries are capacity rated at 20 hours discharge normally - they generally get about half their rated capacity when discharged at 1c. 13s would be a 48 volt Lipo setup. I would just go 12s or 14s myself.

My conversion yielded about 3/4 the volume, less than half the weight and 4 times the usable power vs the lead. I also gained slightly higher voltage and a HUGE difference in voltage under load(way more punch). The difference is huge.

mistercrash · 01:54 PM

Quote:

Originally Posted by RC-Monster Mike

34AH SLA batteries would be a rough equivilent to 17AH in Lipos - Lead batterries are capacity rated at 20 hours discharge normally - they generally get about half their rated capacity when discharged at 1c. 13s would be a 48 volt Lipo setup. I would just go 12s or 14s myself.

My conversion yielded about 3/4 the volume, less than half the weight and 4 times the usable power vs the lead. I also gained slightly higher voltage and a HUGE difference in voltage under load(way more punch). The difference is huge.

This is getting better and better. So instead of 12 6s 5000 mah packs to have 30 amps, I could just go with 8 packs for 20 amps which would be more than enough. Even smaller, lighter and cheaper. With just 8 packs I might even be able to get Hyperions. So have you decided on how much these modules are going to go for? I'd like a snap on lid to protect the balance tabs please

And can you make a single module that can house 8 lipos? I figure that I would have to cut the bus bars.

RC-Monster Mike · 02:26 PM

mistercrash - The module pricing would vary slightly based on size and level of completion. There is a bit of work to get the wall-wrap and it is dependent on size of the batts(have to make a form, then heat the plastic and bend around the form). the upper and lower pieces and lid is the easiest part now, as I should be able to modify my existing design to fit most pack configurations(within reason). The copper plates are easy enough to machine, but the screw posts must be soldered on with a torch - not too difficult, but takes some time and skill. I really haven't done enough to have a good system worked out, so I can't really accurately quote a price yet(not sure on the time aspect). I plan on making another set for 7s packs soon and will get a better handle on the process the 2nd time around.

snellemin - in all fairness, my bike started life as an electric bike from its inception. Most ebikes are cool, though. I think crossing the lighter weight of bicycles with the motorcycle design cues is the way to go - I want to get a supermoto setup for this bike one day and maybe register it for banging around town(I do occasionally cruise on some streets around and always get rubber-neckers). :)

hippie - I didn't make the bike - I only converted it to its current state. I would like to develop an electric frame in the future, though - something that uses widely available parts, but is purposed for e-power. It won't be this week, though. :)

RC-Monster Mike · 01:12 PM

BrianG - I don't want to add 60 degrees of twist...I want to add 30 degrees of twist(90 to 120). The spring is reasonably stiff now and while it may address the issue, it may also lead to fatigue until my right forearm starts to look like Popeye's! Thumb throttles are for quads IMO - I also ride a gasser dirtbike and street bike, so I would rather stick to the twist-type...I just want a better one than what I have!

Arct1k - Chris, if the other half controlled my ride I would probably only get one ride! I like the twitchy throttle I have better than this idea, thank you. :)

Hippie - thanks for the compliment, Mike. I did some more last night and this morning - I managed to get the stock side panels on with some shimming and broke out the trusty propane torch and bent up a rear fender(not perfect, but not bad for a ghetto prototype). Pics attached

mistercrash - thanks for the compliment. "factory" is the look I was going for. The modules are held onto the bike using the two lower screws on each module(into the aluminum post on either end of the modules). I made a custom lower plate that bolts to the bike in place of the original battery plates. I still want to make a top plate for added security, but they are reasonably solid and I wanted to ride this beast. i may have John Holmes string me up a dirt bike rim onto the rear hub and get a meatier back tire on this thing - along with a gear change to get it up into the 50s(maybe - 40 is pretty fast in the trails already).

Having ridden this bike when it was a 200+ pound, top heavy lead sled I can say that the lipo conversion was worth it and then some. The 50 pound weight reduction and much lower Cg results in a dirtbike that handles like a dirt bike now(top heavy and sketchy in the rough b4). The power is unreal, too - it feels easily twice as punchy as my 300 thumper I usually ride and feels stronger than my 400 KTM supermoto, too. A rookie rider on this thing without limiting the power is almost certain to end up badly!

rchippie · 10.05.2011, 01:25 PM

Quote:

Originally Posted by RC-Monster Mike

BrianG - I don't want to add 60 degrees of twist...I want to add 30 degrees of twist(90 to 120). The spring is reasonably stiff now and while it may address the issue, it may also lead to fatigue until my right forearm starts to look like Popeye's! Thumb throttles are for quads IMO - I also ride a gasser dirtbike and street bike, so I would rather stick to the twist-type...I just want a better one than what I have!

Arct1k - Chris, if the other half controlled my ride I would probably only get one ride! I like the twitchy throttle I have better than this idea, thank you. :)

Hippie - thanks for the compliment, Mike. I did some more last night and this morning - I managed to get the stock side panels on with some shimming and broke out the trusty propane torch and bent up a rear fender(not perfect, but not bad for a ghetto prototype). Pics attached

mistercrash - thanks for the compliment. "factory" is the look I was going for. The modules are held onto the bike using the two lower screws on each module(into the aluminum post on either end of the modules). I made a custom lower plate that bolts to the bike in place of the original battery plates. I still want to make a top plate for added security, but they are reasonably solid and I wanted to ride this beast. i may have John Holmes string me up a dirt bike rim onto the rear hub and get a meatier back tire on this thing - along with a gear change to get it up into the 50s(maybe - 40 is pretty fast in the trails already).

Having ridden this bike when it was a 200+ pound, top heavy lead sled I can say that the lipo conversion was worth it and then some. The 50 pound weight reduction and much lower Cg results in a dirtbike that handles like a dirt bike now(top heavy and sketchy in the rough b4). The power is unreal, too - it feels easily twice as punchy as my 300 thumper I usually ride and feels stronger than my 400 KTM supermoto, too. A rookie rider on this thing without limiting the power is almost certain to end up badly!

Mike is that chassis a kit, or a converted motorcycle ?.