Electric Bike Project - Need Opinion

Well.. i don't yet have one of those 2 stroke motor kits, so i don't really have a point of reference on the performance side..

The silence is deceiving, an electric bike that pulls hard.. is as quiet as one that don't.. unlike gas motors, piped and ported.. lol...

But.. i do have a Honda Lead 90 , 90cc 2 stroke vespa looking thing, and my i would put it right along side my Norco at 72v 20 amps in a 20".. up to 50 km/h.. then the scooter walks away. ( that darn scoot will to 90 !! )

If you plan to mod the bike up at any point in the future, get the Brushless. High-voltage controllers are available as a plug-in upgrade if you go with crystalyte it's a direct matchup..

If staying at 48v max, and on a budget, a brushed would do the job, the brushes last a long time, figure a few years before you need to worry about them. However, the brushLESS will need nothing, ever. I have heard of maybe a half dozen bearings go bad from 4 years of reading, and it's usually a bad mill job that killed them from the get go.. rare..

To calculate range.. it's often figured out as wh/km

Watt/Hour = Volts x Amp/Hours.

Example :
48v x 12 ah = 576wh
36v x 12 ah = 432wh

SLA example:

48v x 12 ah = 576ah, but at ebike discharge levels you get 8ah on a good day = 384 usable ah.

I tend to consume from 8 to 15 wh per km on average.. 8 wh is when i cruise on level ground with no wind.. and 15 is riding like a maniac against killer winds without pedaling.

So.. take that 384 wh / 30 km = 12.8wh/km

If you suck back more than 12 wh/km with a 48v 12ah SLA battery.. you are pedaling the difference.

A 48v 20ah Lithium would be 960 wh .. of wich 75 % discharge would still give you 720wh with a 25 % reserve lol..

720 / 30 = 24wh / km.. you can power an X5 with that much juice lol..

My norco has 72 x 20ah = 1440 wh = i get really good range !
 
over the last 4 days - I think I have all I need regarding electric kits ... I suspect a 500w or 600w brushed motor kit + 48V batter should do the trick ... will 48V batteries work with the 36v controllers that come with the more common kits ?

Now with regards to the bike of choice, I hear a lot about the "front end needing to be sturdy" (front hub motor application) ... exactly what type of stregth are we talking about ? Cruising between 18 and 20 MPH for more then a hundred feet at a time is a very good pace - one that's nearly impossible for the typical rider who doesnt have the first name "Lance" ... that being the case, the bike's level of comfort comes into question. I just got a suggestion to consider a suspension bike but are there any suspension forks that have the structural integrity to handle a motorized hub kit ? Most modern (ie ... last 5 to 7 years) have suspensions (either front fork or front AND back) so finding one isnt the question - it's finding one sturdy enough that concerns me ? I can deal with a hardtail w/a front suspension fork and no suspension at all if I must ... but must I ?
 
with regards to weather - I do not expect to do much rain riding but if it rains and I'm out or if it rains and my bike is exposed - will this spell doom ? The batteries will only be on the bike whil it's in use (since they'll be charging when it's not in use) but the rest of the bike may see a spring shower every once in a while ? And in case I run into some surprise percipitation (as is often the case in the Wash DC/No VA area) - should I start praying that it'll continue to operate or for fear of being "shocked" if I'm on it ?
 
Lol.. 48v is pretty save.. the 100v setups might be interesting tho .

But.. like the battery in your car.. SLA is " Sealed Lead Acid " , nothing gets out or in.

The motor, controller, etc.. silicone sealant, hot glue and electrical tape take care of those..

The throttle, this is the bugger, you have LED and Non-LED versions, ( battery indicators ) .. i avoid the LED types, the power line for the led's can create a full-on situation.. = Baaad..

The non-led throttles have a better record, i've seen a video from a guy in australia dip one in a bucket of water, and nothing bad happened..

have to run..

but about the front forks.. it's all about the dropouts.. plate steel... no cast aluminum..and we talk about torque arms..brb
 
Alright i'm back.. i promissed the dog a walk and she was not going to let me forget it ..:D

Dropouts..

Some forks come with quick-release, some don't. Some are 9mm.. 10mm.. 12+ on DH and bmx frames..

You need 10mm( 3/8 equivalent ) for most hub motors. And you need 4" wide for crystalyte 4 series hubs, most places that sell these things will list what sized you need.. pay close attention ! it's important !

In the event that he axle won't fit into the slot just perfectly.. do not file the dropouts or grind them in any way.. using a flat file, remove material from the motor's axle flats instead. ( Only exception is a motor that has the wire exiting the ID of the axle.. )

Try to find a fork with a nice thick flat surface, with enough clearance to tighten a large axle nut.

Some forks for quick release are deep cupped ( most suspension forks of medium to good quality ) but some of the less expensive bikes at big box stores have forks with 1/4" thick fropouts without any recess..

Some road bikes have really thin material and it's not enough to prevent the axle of the motor spinning itself loose and ripping the wires out of the coils..

Torque arms : i'll find a link in a bit with pictures..
 
About riding in the rain.. check this picture !. I have been caught in pouring rain.. and wash my bike with a garden hose !!!!

If you seal it right.. it's not a problem. but it is up to you to do it however! If you don't, water can fry the controller, get into the motor and rust the coils out and eat the bearings.. etc..

When you mount a hub motor, make sure the power wires loop down below the axle so that water runs along the wire and drips instead of funneling into the motor if you route the wires from the top of the frame in...
 

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I ride a Giant Sedona with a front suspension fork, with a front hubmotor. The fork says Magnesium on it but I assume it is actually aluminum? could be wrong.

If you get a quality bike with a sturdy front suspension fork you can run 36V no problem. You could probably do 48V too.
 

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