Electric Bikes - Pre geared motor vs post geared motor/ Chain noise

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Currynut
02-09-10, 10:11 AM
Hello,

This is my first post and i am after peoples advice. I am about to order a multitude of parts to construct my own ebike. The problem is this, I am unsure of weather to buy the pre-geared motor

http://tncscooters.com/product.php?sku=106148 or http://tncscooters.com/product.php?sku=106145
and sacrifice power or buy a ungeared motor and gear it myself.

http://tncscooters.com/product.php?sku=106160

I wish to stay away from hub motors altogether. I am happy to set up a 2 stage gearing system for the the ungeared motor, but my concern is will a chain spinning at 3000rpm be very loud? I assume the gearing down on the pre geared motor is silent but is this the case?

In short, the gearing dose not phase me i am wondering if one will be much quieter then the other.

I have searched through the threads and did not find a devoted thread for noise. These forums are also awesome btw.

Thanks in advance,

Currynut


crackerdog
02-09-10, 12:50 PM
All gearing creates noise as part of the inefficiency of the transfer of energy. A chain going that fast seems dangerous. You certainly won't be using a bicycle chain for that part. The reduction gearing in the 'pre-geared' motor will probably be more quiet since it is encased in grease and has a housing around it but then chains seem to be quieter than gears, so it's a guess. On my geared motors, it isn't as loud as the tires on pavement sound of a car going by but pedestrians can tell I'm coming if there are no cars.

morph999
02-09-10, 07:11 PM
Why are you not interested in a hub motor? Just to let you know, that a motor that works with the chain is a lot louder than a hub motor would be. Hub motor powered bikes are the quietest electric bikes that you can get because they don't really deal with any moving parts, they are brushless.

I'm not trying to stop you from doing your project. I think your project will be great, I'm just letting you know that it will be louder than a hub motor. Have you looked at the cyclone kits? I don't know if they are good kits or not. The motors you have selected might be of better value than the cyclone ones.


Mabman
02-10-10, 11:53 AM
Yes, a geared motor running in to any type of drive will not be stealthy quiet, but overall I do believe it is not that bad. The big thing is that you will able to freewheel which with brushless hub motors is not an option and in fact can be a real drag. Literally.

You might consider this type of motor however as it is more compact and has really good mounting opportunities. http://cgi.ebay.com/ELECTRIC-SCOOTER-BIKE-1-000-WATT-1-4-HP-DC-MOTOR_W0QQitemZ260543196752QQihZ016QQcategoryZ26226QQcmdZViewItemQQ_trksidZp4340.m444QQ_trkparmsZalg o%3DCRX%26its%3DC%252BS%26itu%3DSI%252BUA%252BLM%252BLA%26otn%3D5%26ps%3D63%26clkid%3D77516206909471 77986#ht_500wt_1182

Get a controller and battery that will compliment this and hook it up right and you will have a very good performing machine.

Currynut
02-10-10, 10:36 PM
Hay guys, thanks for the replies.

I think i am going to go with the pre-geared motor. It should be more quiet and as crackerdog pointed out it could be potentially very dangerous. morph99 i am not against hub motors at all, they are great, but unfortunately they limit gearing options. Mabman that is a nice motor, cheap and powerful and compact, unfortunately it does not fix the gearing issue and the chain would still be turning at at least 2500 rpm, so unless a belt drive sprocket could be attached to it, which i fear it could not, it would still be dangerous and to fast. Though if later on i decide i want a more powerful motor i think i will defiantly be heading towards that bad boy.

Thanks for the help,

Currynut

graywolf
02-22-10, 12:19 PM
I would like to know how a 1000 watt motor can be 1.5 hp, since 1 hp = 746 watts?

chvid
02-24-10, 12:35 PM
It is not true that brushless hub motors "cannot freewheel". The geared types like EZEE, BMC, Bafang (8Fun) and FusinMotors (48V motor) freewheel extremely well. I'm running a FusinMotors front brushless geared hub motor on a Raleigh Twenty folder, and it freewheels like a normal bike. You can ride it like a normal bike, no cogging. This is very nice.

CowtownPeddler
02-24-10, 05:23 PM
All I can add is that I was impressed with this motor, or more precisely the mechanism they had for freewheeling the front gears and then hooking the drive motor on the outside of the front gears.

http://www.bike-elektro-antrieb.ch/home.htm

Not sure I'd use the motor, saw an 800w RC motor I was more impressed with.

Still, I haz a hub motor....

dumbass
03-29-10, 07:52 PM
Personally I would never consider a non-geared motor. Every motor has to be geared down to be usefull. The question is where and how you gear it. In my opinion a gearhead motor is the smart way to go and then connect it to your bikes gearing. This gives you the best of all worlds.

I would recommend these motors because they are small and powerful for their size. I have 3 of the 24v versions and love them. Run these motors with a 35a or larger controller. But remember all gears and/or chains will make noise so you won't be able to sneek up on anyone with your bike if the motor is running.

http://tncscooters.com/product.php?sku=106118

http://tncscooters.com/product.php?sku=106130