Poor man's ebike?

Hello,

I'm living in Europe and rely heavily on bicycle for all commute. Since my knees are not what they used to be anymore, I need some sort of electric motor. Unfortunately, I have very little spare money at the moment. On the other hand: I'm totally DIY proofed.
I was thinking of getting a used bike, and beefing it up with a 36v 500W bafang motor from china + a homemade li-ion battery. Perhaps some disk brakes from ebay, and an 8 gear hub gearing set, if I can find a cheap one.
Another option would be beefing up one of those cheapo ebikes. Where I live, there are a lot of german bikes like this one: https://www.amazon.de/ALU-REX-Elektrofahrrad-24Volt-7-Gang-Nabenschaltung/dp/B0013F4I72 Though I'm not sure it's worth the trouble trying to fix one of those: for an instance, is the battery pack behind the seat-bar a valid design option, or does it only make the bike unnecessarily longer and heavier ?
What would you recommend ?

Thank you for your help,

qwerkus

look on eclipsebikes they have cheap cyclone kits they work well

Just find an affordable kit with 7 speed freewheel. If your bike is 8 speed, then just adjust your derailleur to keep it from trying to shift into 8th.

If you can find deal on a used e bike, just needs battery, don't let where the battery was rule your decision. You can carry a smaller, affordable battery nearly anywhere, its going to be only 8 pounds or so. Longer bike rides better, in my opinion anyway.

zackclark70 said:

look on eclipsebikes they have cheap cyclone kits they work well

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Interesting Feeback, thank you. I do not know cyclone motors. Are they noisy ? Same mounting system as Bafang's ? Same power ?

dogman dan said:

Just find an affordable kit with 7 speed freewheel. If your bike is 8 speed, then just adjust your derailleur to keep it from trying to shift into 8th.

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What's the problem with 8 gears ? I read somewhere that 8 gear hubs are a lot stronger than 7 gears, because of the way they are built.

Also, what is your opinion about disk brakes ? Around here, bike shop tell you that V-Brakes are not safe for motors above 350W.

qwerkus said:

zackclark70 said:

look on eclipsebikes they have cheap cyclone kits they work well

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Interesting Feeback, thank you. I do not know cyclone motors. Are they noisy ? Same mounting system as Bafang's ? Same power ?

dogman dan said:

Just find an affordable kit with 7 speed freewheel. If your bike is 8 speed, then just adjust your derailleur to keep it from trying to shift into 8th.

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What's the problem with 8 gears ? I read somewhere that 8 gear hubs are a lot stronger than 7 gears, because of the way they are built.

Also, what is your opinion about disk brakes ? Around here, bike shop tell you that V-Brakes are not safe for motors above 350W.

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cyclone motors are noisy but they are good value 1680w is the best you can get from eclipse bike i would recommend the bb style mounting version
with an upgraded controller its not hard to push peaks of over 3000w you just have to keep the rpm up and tork down to make them last but thats something you can look into later the biggest choice you have to make is if you want to folow the law or not to be honest

Battery behind the post is actually a great place. Center of gravity is much more centered than opting for a rear rack battery or a handlebar location. It makea handling good when centered.
Behind centerpost is the second best place in my opinion, and the downtube is the best. But i have yet to see a downtube battery pack that can hold more than 65 18650 cells.
I have a cheap Arrow-7 e-bike (well known in NYC) and my seat post battery pack holds 100 18650 cells! On manhattan island, stopping at every 3 light or so in heavy traffick, i can do 23 miles from 41.7 volts to 37.5 volts. That's a lot of range !


I mean check out this beauty... can the 48V version can reach 28 mph for 1450 usd brand new with battery.

I bought an old cheap used one but with almost new 36V battery for 600 USD in NYC. Goes to 20 mph.

Thread on it :https://endless-sphere.com/forums/viewtopic.php?f=4&t=89258

qwerkus said:

What's the problem with 8 gears ? I read somewhere that 8 gear hubs are a lot stronger than 7 gears, because of the way they are built.

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What you have heard applies to normal bike wheels, not hub motors. These days, if a normal bike wheel has 8 speeds, it uses a cassette hub, and if it has 7 speeds, it uses a threaded freewheel hub, with a weaker axle.

Almost all rear hub motors, and all of the cheapest ones, use a threaded freewheel and are spaced for the 7-speed kind. But their axles are massive, not weak like they would be on a normal bike.

There are 8-speed threaded freewheels available, but they are few, more expensive than 7-speed, and most importantly they take up more space than a hub motor has built into it. To use one, you have to add spacing to both your hub axle and your frame, and you have to increase the offset in the wheel's spokes. Another tradeoff is that the wider the freewheel, the easier it is to break the side cover of your hub motor by pedaling.

zackclark70 said:

cyclone motors are noisy but they are good value 1680w is the best you can get from eclipse bike i would recommend the bb style mounting version
with an upgraded controller its not hard to push peaks of over 3000w you just have to keep the rpm up and tork down to make them last but thats something you can look into later the biggest choice you have to make is if you want to folow the law or not to be honest

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Thoses are values wayyyyy beyond my aim. I'm looking for a PAS system, which helps me riding uphill, or starting the bike when it's fully loaded. Hence 350W or 500W should be enough.

Matador said:

Batteru behind the post is actually a great place. Centernof gravity is much more center than opting for a rear rack battery or a handlebar location. It make handling good when centered.
Behind centerpost is the second best place in my opinion, and the dountube is the best. But i have yet to see a downtibe battery pack that can hold more than 65 18650 cells.
I have a cheap Arrow-7 e-bike (well known in NYC) and my seat post battery pack holds 100 18650 cells! On manhattan island, stopping at every 3 light or so in heavy traffick, i can do 23 miles from 41.7 volts to 37.5 volts. That's a lot of range !

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Thanks for the input about the battery position; you nearly got me convinced. My main concern is that I use a trailer very often for transportation; long bike + trailer = harder to maneuverer (in my opinion).

Chalo said:

What you have heard applies to normal bike wheels, not hub motors. These days, if a normal bike wheel has 8 speeds, it uses a cassette hub, and if it has 7 speeds, it uses a threaded freewheel hub, with a weaker axle.

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Thank you for your explanation. I was going for a mid drive motor - not a rear hub, hence my concerns about a weak hub gear system. Now you got me wondering: if rear hub motor already offer internal gears, why do so many of them also come with derailleur ?

Hi,
My first bike was a very cheap and cheerful one. Q128 500w rear hub with a 7spd freewheel. I assembled my own battery from lipo cells from hobby king which worked really well. Although the batteries have been replaced (due to my neglect) the hub and controller are still working well after about 8 years. If I were to replace I would go for the Q128H which is rated for 800W.

V brakes are OK for a geared hub if you maintain the bike properly and don't ride through huge muddy puddles all the time. For road based commuting they would be fine IMO.

Good luck!

If you are living in Europe then you might have to be more aware of the watt limitations of your country. 250w is considered an ebike in most EU countries.

Cyclone motors are from 250w all the way to 1860w for the standard size its better to get something a bit bigger and restrict it than to over work a motor

Nah, rules for my country are 500w and 25km/h max. Past that, you need a license.

I found this one for a good price: http://www.velo-electrique.com/Images/futuro_explorer_2009/explorer/explorer1.jpg
Mine would be used, and doesn't look nearly as shiny, but it's cheap.

What do you think ?

qwerkus said:

Nah, rules for my country are 500w and 25km/h max. Past that, you need a license.

I found this one (used) for a good price: http://www.velo-electrique.com/Images/futuro_explorer_2009/explorer/explorer1.jpg
It's quite heavy, but looks fine.

What do you think ?

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i have seen a few of those about around the uk they are ok for there price but dont expect to much speed and there the same as most hub motors they suck on any good sized hill

qwerkus said:

Nah, rules for my country are 500w and 25km/h max. Past that, you need a license.

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Dont worry about that mate, just buy the 1500W Cyclone and ride like a gentleman.

markz said:

qwerkus said:

Nah, rules for my country are 500w and 25km/h max. Past that, you need a license.

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Dont worry about that mate, just buy the 1500W Cyclone and ride like a gentleman.

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well there is that but i cant really encourage people to break laws as you can get in some serious trouble because most places will treat you the same as they would if you were driving a car with no licence tax insurance and whatnot

zackclark70 said:

i have seen a few of those about around the uk they are ok for there price but dont expect to much speed and there the same as most hub motors they suck on any good sized hill

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Well, my french is not the best, but from what I gather here, the quality is really crappy: http://www.avem.fr/avis-utilisateur-velo-electrique-isd-futuro-explorer-mauvais-investissement-648.html
Basically, I would have to strip the bike from all it's parts (except perhaps the saddle), and replace it with better stuff - starting with a better motor. I wonder if it is worth it...

qwerkus said:

Now you got me wondering: if rear hub motor already offer internal gears, why do so many of them also come with derailleur ?

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Most hub motors are direct drive, with no gearing at all inside them. Geared hub motors have a reduction gear for the motor, but not selectable ratios for motor or pedals. Of all the hub motors I know about, only the SRAM Sparc (a weak and slow hub motor) has multiple internal gears, and those are only for the pedal drive.

Bottom line it's an electric bike the heart of the electric bike is the battery good a good name battery not just the word Panasonic not just the word LG but what cells are inside that battery and make that a good purchase. Are not cheap Chinese generic junk. Bafang is fine.

Can't you buy any bike you want and just change the controller/battery to suit your need ?
Buy a bike with 500W or 1000 W, and take a smaller controller with lower amp outoput and voila... your legal.
Your motor will be in comfort zone, never overheating....

Buy a Arrow-7. Same biog battery, motorcycle-like hydrolic brakes. Tank-like amramture. Full-equipped and with a stock 1kWh battery.


For 50 more dollars, buy a smaller controller to put in the controller box. There, you just downgraded from 500W (800W peak) to 250W and you're now legal.

Justin at ebikes.ca has a motor with gears.
TDCM IGH model 395 and 305
http://www.ebikes.ca/shop/electric-bicycle-parts/motors.html?motor_manufacturer=100

Quick Overview
TDCM Direct Drive with Internal Gear Hub - Unlaced. 30mm stator, Fast 395rpm winding, 5 Speed Sturney Archer Pedal Hub with Shifter. 1/8" Chain 18T Sprocket. 4-bolt Rohloff disc mount.

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TDCM Internally Geared Hub - 30mm stator, unlaced, fast 395rpm winding for 20" wheels. Internal 5Spd Sturmey Archer gear hub, disc brake compatible with 4 bolt Rohloff disc rotors, compatible with Statorade in for maximum thermal performance. Requires 1/8" Chain and is best with slotted horizontal dropouts. Does not use work with conventional torque arms and supplied anti-rotation plate can be difficult to engage in shallow vertical dropouts.

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markz said:

http://www.ebikes.ca/shop/electric-bicycle-parts/motors.html?motor_manufacturer=100

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Useful link: thanks!

Yes, that's probably going to be the case: buying a cheap bike, and adding motor + controller - initial plan. Sadly no arrow 7 where I live...
Building the battery from scratch is also on my todo list, but that darn battery welding set is nearly as expensive as a new samsung battery pack!

qwerkus said:

Yes, that's probably going to be the case: buying a cheap bike, and adding motor + controller - initial plan. Sadly no arrow 7 where I live...
Building the battery from scratch is also on my todo list, but that darn battery welding set is nearly as expensive as a new samsung battery pack!

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If you have a chance one day, go in manhattan harlem : 226 West 103th Street and Broadway.... It's a sop called Arrrow II bikes.

I have a very old version of it. Love it. My battery is not old thoug (100 cycles).... It's a 36V 10S10P 20ah... I dont have the one with samsung cells.
I got the one with cheap chinese cells .... Still, look at these numbers.... I'm mainly doing throttle only (My system is 350W continous) :

July 13 & 14 --------- Departure 42.0V (100%) -----> Arrival 38.4V (70%) -------- Distance : 13.5 miles ; 22.0 km
July 15 --------------- Departure 41.8 V (99%) ------> Arrival 39.9V (81%) -------- Distance : 8.4 miles ; 13.5 km
July 17 --------------- Departure 41.7 V (98%) ------> Arrival 40.6V (88%) -------- Distance : 3.0 miles ; 4.8 km
July 20 --------------- Departure 40.5V (88%) -------> Arrival 39.2V (77%) -------- Distance : 9.8 miles ; 15.8 km
July 21 --------------- Departure 40.5V (88%) -------> Arrival 37.6V (63%) -------- Distance : 13.7 miles ; 22.4 km
July 22 --------------- Departure 41.7 V (98%) ------> Arrival 38.6V (71%) -------- Distance : 13.2 miles ; 21.2 km (done in real 1:15 stop included... so average of 17 km/h in traffic and pauses).
July 23 --------------- Departure 41.7V (98%) -------> Arrival 38.8V (73%) -------- Distance : 10.6 miles ; 17.0 km (lots of facing wind and 2 miles going slight uphill, rolling faster than usual).

I think I can do 35 miles (60 km) range and still have 25% left (33.0V) but starting there, cells will get unbalanced....
With my setup, my cells see 0.5C.... Pretty reliable for commuting needs.

Matador

You might be able to find a used ebike or bike with an electric conversion.

Hub motor systems are simple, reliable and cheap, besides that they work very well. Direct drive hub motors have fewer failure points than geared hub motors, but DD hubs do weigh more and have less acceleration away from a full stop. From 10 km/hr up to top speed , direct drive and geared hub motors provide similar performance.

Geared hubs have some gear whine, direct drive hubs can have some harmonic noise at some combinations of speed and power setting. A real sine wave controller probably produces less harmonic noise than a clipped wave controller.

Hub motors that use Hall sensors have more failure points than sensorless hubs. Sensorless, brushless hubs have three wires going to the hub, hubs using Hall sensors have more than three wires, there are some smaller wires for the sensors. I'm thinking that some Hall sensor hubs and controllers can work as sensorless if sensors fail, but some others can't. Not being stranded by a sensor failure is a good thing. My sensorless, direct drive hub sometimes needs a tiny forward push to start, a friends Hall sensored, gear drive hub does not need that tiny forward motion.

Lead gel cell batteries can give good service but they are heavy, have less power and have shorter range and lifespan compared to lithium batteries. My 36v gel cell pack weighs about 12kg and has an effective range of about 19km, compared to my 13s, 4p, GA cell, 48v lithium battery that weighs 3kg and gives a range of about 30km. Cost of the 36v gel cell battery and charger would be about 1/3.5 of the lithium battery and adjustable charger. The gel cell battery can power the bike comfortably at about 18 km/hr, the lithium battery gives and easy speed of 25 km/h. Battery range is more or less determined by battery weight, for each respective type of battery.

The Aotema direct drive, sensorless, 36v front hub has been very reliable for me. The controller for it is made for 36v but I use it for both 36v gel cells and "48v" lithium batteries that actually start out at 52v and decline to about 48v. Again, the lithium battery pack is 13s, 13 cells in series. Used on "48v", the Aotema 36v controller does not have a low voltage cutoff, but I never run the voltage below 47v, and never charge above 85%.

Cost of my 18 speed ebike, including the gel cell battery and charger, was $180, about 154 euros. I found it on Craigslist, don't know if CL exists in your country.

Point is that you may find a reliable ebike for well under 200 euros. If it has lead gel cell batteries, it will have less range and speed than it will with lithium batteries, but it will still work and your pedaling effort will be reduced by a lot. A later upgrade to lithium batteries is very doable after money becomes available.

I hope this babble helps you in your decision making. Apologies for grammar and spelling problems.

Backtracking a bit in the discussion,, the main reason to go 7 speed on the 8 speed bike is spacing. Because the motor is wider than the 8 speed hub, only 7 gears fit the space.

You can go with an 8 speed, if,,

you find the freewheel

don't mind bending the frame out to make the space bigger

and the motor itself has a long enough axle on the gear side, to still get a nut on it after you make the motor and gears wider, using some special spacer washers.


My take, for one more gear,, hardly worth all that. Put a 7 speed on it, adjust the derailleur stops, and good enough. If you are a fussy type, it won't index absolutely perfect though. index it for the high gears, and you will get good enough shifting on the gears you will be using.