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tyrslider

tyrslider

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Ok, so I want an e bike that does reasonable speeds i.e. 35-40 (45-50?).

I figure I want at least a 1000W. If I go w/ a 48V 30Ah system I should have a reasonable range. I want to have 2 BatPacks each 48V 15Ah. This way I can ride light (15-20lb bat) for short distances and load up (30-40lb bat) for longer.

I've found a source for the bats (LiFeP04) and I've inquired about price. They want to know all the specifics (max discharge, peak etc) in order to design a proper bms.

So the ?'s begin.

Who to get the Motor from? Magura sells throttles are they what I want (I do want a throttle)?

I get the specs they're asking for but I've not found the perfect motor and controller and I'm trying to get an idea of how much $ I'm into it to do what I want.

Cheers! any input is appreciated!
brnot
 
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Don't know anything about it, but there are people here who do... Thud for one. This is a new direction for you. I know that when I saw Thud's bikes at the Ohio race last June I had my eyes opened up to what electrics can do in terms of speed. Pretty awesome. They have come a long way in a short stretch of time. I'd PM Thud as he knows an awful lot about this and has designed a two speed transmission, a Lexon (don't know how to spell that... the clear plastic like stuff that is really strong) drive sprocket and is cutting edge.
SB
 
First of all , those aren't reasonable speeds for a bike. You'll need some light motor bike suspension and matching tires (what if you hit pot hole with that speed?)and rims and a frame which can do the job (like mountain bikes). Not to mention brakes. Second , 1000 W isn't enough for those speeds , more like 2500 W or 3000 W(or even more), because of air resistance (it grows exponentially with speed). At 48 V , you get 1000 W using ~ 20 A continuous, so your motor(and controller) must be capable to withstand at least three times that (Amp wise). Permanent magnet, in wheel motors can do that (Crystalyte comes to mind , series 53xx , or 54xx), other kinds too , but less eficient (less range, more heat). Controller could be some Kelly (depending of what you want), certainly not some RC cheap toy.
There are formulas for calculation of all these parameters(like air resistance) on Endless-sphere forum (link isn't at hand), but you should really do some more research to get idea how to achieve what you want.
Mind you , 15 AH wouldn't get you very far with that kind of setup (juice consumption) , even on the flat ground (20 - 25 miles?) and the "throttle" is the last thing on your shopping list. $ wise (without battery packs) , around 1000 , give or take few hundreds (check the Kelly site and Crystalyte and you'll need some more fuses , switches and, probably , cyclo-comp gadgets ). Good luck !
 
Thanks Guys,

I'll be back w/ more ?'s shortly!

Cheers!

P.S. Will pm Thud and am checking out some co's zabac mentioned!
 
Sorry to be a wet blanket, but I agree that 40mph is neither safe nor comfortable on a bicycle (for most of us). Bicycle tires and brakes will not hold up at that velocity.
If you are determined to build a bike that will do those speeds, it will be far cheaper to do that with a gas motor from a small motorcycle.
 
wheelbender6 said:
Sorry to be a wet blanket, but I agree that 40mph is neither safe nor comfortable on a bicycle (for most of us). Bicycle tires and brakes will not hold up at that velocity.
If you are determined to build a bike that will do those speeds, it will be far cheaper to do that with a gas motor from a small motorcycle.
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1. I comfortably ride at 40ish often and quite safely. HuckerSteves 70cc shifter does 45+ when he rides w/ the Mosquito Fleet on Moped Monday rides; He's got 1000's of miles on the same tyres and brakes.

2. "Top Shelf" (and even much of the cheap $#!t) Bicycle tyres and brakes Do hold up at those velocities.

3. I'm not looking for cheap, and actually I think your still not entirely correct when the 5000 recharge cycles of the LiFeP04 bat's are taken into consideration.

4. Your not a wet blanket! I get it, we're not advocating riding illegally or in an inherently unsafe manner. This bike will be entirelly legal and safe (w/in reason).

I've not decided what platform I'm going to use but it will be a stout set-up w/ excellent brakes, tyres and componentry; likely full suspension.

W/ that out of the way I'd like to focus on the legistics of making this build a reality. I'm curious about spec'ing out the the components of the system.

They're asking me what kind of max discharge I need when they advertise cells w/ a 3C to 5C rating!
W/ my 48V 30Ah bat's that's up to 150A and 7200W so, I assume, they build a bms that'll control the max output to w/ in the motor's specs? Also they want to know how fast of a charger I want, what are the pro's and con's of fast vs slow in LiFeP04's? Or is it just charger expense?

Cheers! Evan

brnot
 
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Like others here, I get nervous when someone proposes a high speed ebike, because when an innocent bystander gets killed there will be a whole slew of new regs on ebikes and they WILL be enforced. However, if you are interested in speed, go over to Endless-sphere. That forum has lots of builders using high-powered RC motors and LiPo high C batts - jd
 
Thanks guys!

I'll check it all out.

The bike will likely be liscensed as a motorcycle, though I could certainly fly under the radar w/ it. I've ridden down hwy 99 @ 40mph on my gas bikes and the Fuzz pay no mind. I wear a DOT halfshell, gloves, pants, and a good pair of shoes almost always and I obey posted speed limits, traffic laws etc.

Thanks for the help! Cheers! Evan
 
tyrslider: I believe going electric for the speeds you suggest will be very expensive. I have considered electric for our tandem so I can still fit the wife on it and still have my current gear and brake setup. EcoSpeed makes a setup that replaces the crank with there motor crank setup. This is available with a 1000watt motor. I have considered this because It allows you to power the bicycle on all the rear gears so you have better start up and hill climbing. I have also looked at the Phoenix system that uses a hub motor and is available in three windings and three different voltages. The good thing about electric is not needing to register and license where I live. The bad part is limited distance and the weight of batteries and of course more expense.

EcoSpeed, Worlds Best Electric Assist

Electric Bike Conversion Kits, Crystalyte Phoenix, RoadRunner, Sparrow Hub Motors
 
I rode a motorcycle to every place I went in my younger years. I don't heal near as fast anymore. To each his own.
 
Definately check Endless Sphere forum out, es member Hal has some nice Colossuss (brushless rc motors) that would see your speeds achieved and surpassed for 150 bucks IIRC, with your 30ah pack and cruising speeds of 30mph you will have some serious range, I use a 44v 20ah Lithium Polymer pack myself and get near 50km range more if i dropped the speed to 40ish Kilometers an hour, the pack weighs a mammoth 6kilo and is capable of 300amp bursts without troubling the cells. Bike has a top speed of 60km/hr so fast enough for when the roads are clear and you want a lil funz haha.. Go with medium to high end Downhill mountain bike compnents and you wont have an issue with 70km/hr (45mph)speeds
 
Sorry, been away for a tick!

All is good input and taken not lightly

I've always contested that mb's were for expert cyclists (m/c, bicycle etc) only. W/ possible exception to around the neighborhood jaunts and the like.

But I guess everyone rides in their comfort zone! I'm more confident riding fast on a quality bike than on a moped; in SeaTown as long as your obeying traffic laws, seems nobody cares. And by nobody I mean the fuzz!

This bike will be my winter build. I'm leaning toward this bike for starters:

Swobo Bikes

I'll add some fr suspension, discs and some speeds!

Cheers!
 
First post here....let me say I race plain old pedal"No engine bikes" and hit 30-35 on flat ground and 55-57 pedaling down hill.....my bike will not just fall apart at those speeds and it is completely engineered to preform at those speeds, engine or not. You could say "Well that is without the extra weight of an engine and batteries" Well I weigh 175 and I am pretty sure my bike was designed for at least a 200 pound guy to ride it?

Good luck on your build. I am going to go the chopper route myself....something completely differant than what I ride to race and for health.
 
swingslammer said:
First post here....let me say I race plain old pedal"No engine bikes" and hit 30-35 on flat ground and 55-57 pedaling down hill.....my bike will not just fall apart at those speeds and it is completely engineered to preform at those speeds, engine or not. You could say "Well that is without the extra weight of an engine and batteries" Well I weigh 175 and I am pretty sure my bike was designed for at least a 200 pound guy to ride it?

Good luck on your build. I am going to go the chopper route myself....something completely differant than what I ride to race and for health.
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Just out of curiosity, what kind of bike do you have and how much did it cost you?
 
It is a "Dawes", a hand made British bike, there is a cheap Asian knockoff but I have the Real British deal. Cost about $1,100 and is just the lower end of their line. I only weighs 20 pounds and the tires go to 140 psi.
 
That's what I figured.. You're using an expensive carbon fiber bike, that's why the very high speeds don't bother you.


Most people use the 99$ walmart type bikes to pu motors on...

I don't suggest anyone should ride anywhere close
To 35-40 mph on a regular bike with motor...
 
Also, you are probably an accomplished rider with many hours in the saddle. It probably took you a some time to build up to those speeds. FB has been around on smokers for a while too. Some of us here worry about beginners, but that discussion is better off on the Safety forum - jd
 
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Well, there was a thread maybe on another forum, where a guy decided to go the electric bike route, but a high speed one (and not an experienced rider).
Unfortunately, he ended up in some form of accident and subsequentially died...
It is a worry I personally have with people who want to do high speeds on a "vehicle" not meant for such speed, vibration, etc.
 
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