Electric mountain bike questions - RC-Monster Forums

BL_RV0 · 02:24 AM

Hey guys, I have a 2008 Giant Rincon as my town cruiser and I've had the idea of electrifying it for the longest time now. I was hoping to do a HV setup with some of those ebay A123s that Neil found a few days ago and a HC outrunner. But with my gear ratios and too-high motor RPMs, I've decided that unless I run a hub motor (too expensive, lol) I couldn't do this. So, my question to you is, would a turnigy 63-74 170kv outrunner, 150a 6S lipo esc and, say, 6S4P A123 be adequate for a ~35lb fully loaded bike with a 110lb rider suffice? Or would it run too hot? FWIW: I'd like to get ~30mph out of the bike.

BL_RV0 · 05.30.2009, 02:31 AM

Ok, with the smallest sprocket I can find for a 10mm shaft (9T) and the gearing/tire size on my bike, the bike will be geared for 38mph on 6S A123. But facotur in the extra weight and such, that'll put it around 30mph. Perfect!

Rebelgium · 05.30.2009, 04:45 PM

You really should check this project out. I just found it 5 minutes ago!
http://www.hobbycity.com/hobbycity/f...p?TID=289&PN=1

brushlessboy16 · 05.30.2009, 04:51 PM

Holy crap those are some big motors!

wow 45 on a bicycle- i what a cop would do if you broke the speed limit on a bicycle.

I gotta look into this now

scarletboa · 05.30.2009, 06:35 PM

i think the biggest problem would be pedaling. you would still have to pedal even if the motor was doing the work.

brushlessboy16 · 05.30.2009, 06:53 PM

it would be neat to have the pedals powering a little generator. to get a little more range.

i would scrap the pedals and make a full e-bike

nieles · 05.30.2009, 07:23 PM

Quote:

Originally Posted by Rebelgium

You really should check this project out. I just found it 5 minutes ago!
http://www.hobbycity.com/hobbycity/f...p?TID=289&PN=1

http://endless-sphere.com/forums/vie...hp?f=28&t=8347

an 18 page thread about this project

Rebelgium · 05.30.2009, 09:20 PM

Quote:

Originally Posted by scarletboa

i think the biggest problem would be pedaling. you would still have to pedal even if the motor was doing the work.

lol if that would be the biggest problem, everyone would make them!

BL_RV0 · 06.01.2009, 12:25 AM

Quote:

Originally Posted by brushlessboy16

it would be neat to have the pedals powering a little generator. to get a little more range.

i would scrap the pedals and make a full e-bike

I'd take the pedals off and just mount footpegs, unless I can figure out some engageable pedaling system.

Just an update for everyone:

My planned setup for now is: TGY 63-74 170KV outrunner, SS 100A ESC, and 6S4P A123s.

Patrick · 02:04 AM

Maybe if you put the motor sprocket on the other side of the wheel then you should be able to keep the normal one way bearing (I assume it's a one way bearing) that lets you free wheel without pedaling. Don't know how hard that will be to make work, but it's something I'd look into if it was me doing it.

Metallover · 06.01.2009, 02:04 AM

Just a heads up 1000w is quite a bit of power. Look up 1000w currie on youtube. It'll probably get you 25-30mph. You're dealing with much more so be careful....

BL_RV0 · 06.01.2009, 10:36 PM

This will be

BL_RV0 · 06.02.2009, 10:44 PM

I think I got my setup figured out.
Turnigy 63-74 170kv outrunner
SS 85-95a ESC (used to be SS 100a)
2 Turnigy 6s 5000mah 15c lipos in parallel (6s 10000mah)
Apparently there was a marking error and turnigy 15c packs are actually 20c. That'd be nice!

BL_RV0 · 01:33 PM

Bringing this thread back up. I'm going to change this design a lot. Planned setup is Ben's monster motor with gear and sprocket reduction, 12v 30ah lead acid batteries and a 30a 36v e-scooter controller (I have all of this sans the motor). The gear reduction will me 15/81 using mod1 gearing on 8mm shafts (only combo that SDP-SI had that make a good speed). This will be achieved using PNs: S10T10M015S0508 and S10T10M081S0508 as the pinion/spur respectively. The next/final reduction will happen using the 32T rear sprocket on my bike and PN A 6M 7MHZ12713B as the "pinion" sprocket, yielding a 13/32 reduction. Ben's motor is 380Kv and will be used on 12v 30ah yielding 30mph, but probably less when IR is factoured in. I'll use some #40 chain to run from sprocket to sprocket. All of these components will be mounted in a large box on the rack over the rear tire, and crank mechanism will be removed and pegs installed. Only thing I'm worried about is my 13T sprocket- it's acetal resin with a brass insert. Will this work or will all the teeth shear off under load? I can't find a metal one with the same spec for the life of me. Quite a strange sprocket though- 8mm bore, 13T, and #40 (1/2") pitch. What do y'all think?

PS: I have 3 12v 10ah packs, so I can run 12v 10ah, 20ah or 30ah.

Patrick · 06.15.2009, 02:09 PM

Quote:

Originally Posted by BL_RV0

PS: I have 3 12v 10ah packs, so I can run 12v 10ah, 20ah or 30ah.

Why not 24 or 36v 10a?