Mid monster/Hub monster powered cruiser in mind, seek advice

[Vanarian]

John,

Ok no problem, never considered the MiniMonster. It sure has its advantages but considering I want to occasionally ride with madame I'm thinking that it would suffer from the total weight and hills. I'm a bit of "big block" guy don't tickle me too much on the HubMonster :lol: Plus it will already be a challenge to put the Mid Monster in a optimal mid mount position (yes i've really been thinking of putting the Hub Monster in mid mount too, Custom bobber look-a-like). I'm figuring the proper dimensions, at least with the diameter from both hubs I can arrange the frame. More adaptation needed since these motors are outrunners, I'll solve this anyway.

I'm trying to maintain a low weight limit around 60kg, more easy to say than to do, a motorcycle fork can weight around 8Kg, torque arms can weight between 5-8, considering I will carry more batteries than I was thinking it can also count its toll (thanks to Lipos it's not too much of heavy stuff). Controllers usually don't exceed 4kg each if I recall. The frame itself bare thick alu I'm estimating 15kg for the moment, maybe I'm over estimating. Leather seats will bring some weight too. What worries me are the rims and brakes weight, I finally found tyres worth the look and performance : Avon Cobra! Match it with a bobber like set of rims and it's killer look with good wear thread and grip for high speed and corners.

By the way was I correct with my layout logic or did I put too much batteries? I.E. just align batteries for the desired voltage, then instead of parallelling the total line, just add the batteries required for amperage? Hard to write, easier to show, example :

-6s-
-6s-
-6s + 6s|6s|6s-
-6s-
-6s-

or it must be a full
-6s|6s|6s|6s-
-6s|6s|6s|6s-
-6s|6s|6s|6s-
-6s|6s|6s|6s-
-6s|6s|6s|6s-

I know that just adding batteries in parallel raise amperage, series them raise voltage. Wondering if I'm over calculating by paralleling the totality of batteries.

 

[John in CR]

It has to be the full thing. You need the same amount in parallel for each cell in series. For keeping it simple you might want to avoid the 6s blocks, because you can't as easily break it in half for using 2 equal chargers. My pack is 20s + 10s, so while I use 2 chargers, I have to use different connectors so I can't connect them to the wrong portion of the pack. My reason for doing it like that is all my other bikes are 20s and that charger gets shared. If you already know a bargain 120V charger for lithium, then never mind. If you're talking about RC lipo (the more flammable stuff, but higher current rating and cheap) then the 10s packs work fine and are actually 2 5s packs with separate wiring in one wrapper, so it would be simple to make your pack 15s + 15s to accommodate 2 cheap chargers. The 10s packs often on sale for cheaper at HobbyKing...I guess isn't as popular.

 

[Vanarian]

Ok thank you I understand better

Plus you're right about the flammable hazard I'll add a steel enclosure on the bike instead of a simple Alu or wooden one. Or inner layer of steel and outer layer of wood. Need to dig holes in a direction where I won't risk backfire in case of problem.

I'm surprised to see how cheaper the HobbyKing packs can be than what I find locally. These Lipos things are a bit creepy no wonder it can drive so much power.

 

[John in CR]

In the for sale section of the forum there's a guy in Poland selling 4p10s blocks that were destined for Bosch ebike packs, which didn't pass inspection due to tab weld issues for extremely cheap. If you can get the few missing tab welds done locally then that's a way to get a much lighter, safer pack, and cheaper pack than RC Lipo. You'd need to go with 4 of those strings in parallel to cover your current demands X 3 strings long, but $1200 or so plus ground shipping from Poland would net you a 24-25kg pack of nearly 5kwh giving you extreme range at a nearly impossible to beat price.

 

[Vanarian]

John,

I'll look for it it's truly a killer price (specially with money conversion). By the way could you PM me two total quotes for both Mid Monster and Hubmonster shipped ? I've been measuring the space I can allow to the hub and I've got less than I thought but still plenty even for a mid drive fat Hub monster :lol:

I'm more worried about the overall form of the battery room since I can't get them to stick to my knees.

Also Bosch is perfect I can just put a fake "Bosch" emblem on the Hub with a fake "250w" sticker to lure cops if they want to check the beast.

I'm breathing, no more grades to pass before January !

 

[marcexec]

Hey Vanarian,

did you make any progress on this?

 

[Vanarian]

Hey Vanarian,

did you make any progress on this?

Hi Marc,

No I suspended this build in favor of a more personal project I principally wanted my cruiser to go around the sea border with my wife (and occasionnaly get my bursts of speed) but she finally never liked the idea so the expense wasn't worth it. All the funds went into my efforts in bringing to life high power electric inline skates. And I hope to see the end soon!