Are conversions worth it?

Goggs

Veteran
Hi folks. Last year I was lucky enough to get to cut about on a Giant full-sus e-bike & I loved it. It kinda ended in tears with a heavy crash but I fell in love with the concept right there. I hoped to be able to buy my own but finances aren't working out so well. I know there are some cheaper options but when I examine the specs there's corners being cut all over the place.

So here's what I'm thinking. I currently own a 2016 Cube Hyde Pro. It's a 58cm frame so I think it should have enough space for a bettery or two. It also already has Shimano hydraulic disc brakes & a Shimano Nexus 8-speed IHG. I'd like to retain the Nexus hub so that rules out a rear hub motor which leaves either front hub or crank drive. I don't fancy the idea of a fwd bike so I seem to be heading for the crank drive system.

Can anyone recommend what I need to buy? I can't afford top of the range but I'd never buy at the bottom either so what's going to work for my bike? Will anything work?

One more thing, I live in France and as far as I can tell Throttle is permissable.

Any and all help gratefully received.

Thanks, Gordon.
 

Cycleops

Legendary Member
Location
Accra, Ghana
Sounds perfect for an electric conversion. I'm no expert but it seems the most popular is the Bafang mid drive system. Should work out about £3/400. Could you salvage the battery?
I'm sure someone will come along with more options. There are plenty of videos on YouTube to check out.
Good luck.
 
OP
G

Goggs

Veteran
Thanks for the input. Yes, I think the base bike should be well up to the task as it's already a chunky frame. I don't have a battery to salvage because the Giant is owned by my boss. I'm still allowed to use it but I don't because it's so valuable. Also, I ended up in hospital needing an operation after my last outing so that bike's kinda tainted.
 

Ananda

Active Member
Location
Athens, Greece
Dont fall for the power craze. 250w is ok, it is what a fit human can do, use more than that and you will end up with either a very heavy and expensive conversion, or a very short range. The investement would be similar to buying a new mid of the pile ebike.
Also, having a mid drive with a torque sensor provides a superior cycling experience than one with only a cadence sensor.
For the above reasons, I would go for a tsdz2 mid drive which retails with a battery at around 600€.
 

CXRAndy

Guru
Location
Lincs
I'm currently doing an e bike conversion for my wife's bike. I'm using a TSDZ2 motor kit with custom firmware-You can buy the standard kit a fair bit cheaper. Its a torque sensing kit, so responds to power applied by rider. It also has a thumb throttle if you desire it over torque sensing.

I've got all the bits now and its currently fitted as of yesterday, I will need few more days to tidy up the cabling. I have thread started and will be updating with pictures and video clips

https://www.cyclechat.net/threads/ebike-conversion.251127/

Its much cheaper than buying a ready designed ebike-you have to be realistic, it wont look as factory, but should perform aswell if not better.

Edit just done a little test ride with the battery wiring temporary taped up. Its lovely and smooth :biggrin:
 
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CXRAndy

Guru
Location
Lincs
Much cheaper from here, even with import duty. I bought the TSDZ2 750W kit

Its quite easy to have peak power 500+W when accelerating hard. A better spec motor should be able to cope with higher average Watt output then stressing a lower powered motor.

I took my Wife's new bike for a little test, The motor kit was displaying 200-300W quite easily for me
 
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CXRAndy

Guru
Location
Lincs
Cheaper from where?
Sorry forgot to drop link

https://www.electrifybike.com/store/c24/Mid-Drive_Motors.html#/

This is where I got mine. I got the TSDZ2 with custom firmware. This is a torque sensing drive. I understand the Bafang is speed driven so you dont need to put in an effort on the pedals.- I might be wrong with the Bafang design.

The TSDZ2 takes a proportion of your own effort and multiplies that with additional motor drive- the higher the level more motor power is given. Similarly if you put alot of your own power, the motor will do the same until it hits either speed limit or Max's out on the power capability.

The custom firmware allows alot of adjustment to alter the way the motor behaves.

I run a 52Volt battery which means I can reduce the current to motor, but still achieve power capability I want.
I
have limited the motor to 500W, which for me is a achievable, but not for my wife-which the conversion was done for.

She on recent rides is asking the motor to produce about 100W of assist. With that type of power the bike could last 6 hours with its battery 13.5Amp/hr.

She tootles along at 14-15 mph without too much effort, which is absolutely perfect for her .
 
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Ananda

Active Member
Location
Athens, Greece
I run a 52Volt battery which means I can reduce the current to motor, but still achieve power capability I want.
I do not understand this. The torque the motor produces for given rpm is proportional to the current through it and the power it produces is torque times rpm. So the only way you can have power without too much current is to pedal at high cadence. No?
What does the battery voltage have to do with anything other than being able to push more current through the motor?
 

CXRAndy

Guru
Location
Lincs
Electric power

Lets say its a 36v motor rated at 360W 36*10amps=360W. N

If you use a 52V battery you only need 6.9amps to get equivalent power.

Ive read on a few forums-some guys using 70+ Volt batteries to gain even more power and revs. There is a limit before bits will burn up but I'm joining the Ebike scene way behind the curve and lots of practical testing has lead to these higher voltage motor setups

Less Amps means less heat

Using a higher voltage allows motor to spin faster.

( I limited the max current with the custom firmware to 10 Amps). Using 52V*10A=520W

The TSDZ2 has about 80Nm of torque
 
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Ananda

Active Member
Location
Athens, Greece
Thats what I am saying as well. By using a higher voltage battery you can extract more maximum power out of the motor but only at higher cadence. That 10A is the limiting factor on the torque. You will never achieve nowhere near 80Nm of torque with such low amperage.
I other words, high voltage equals high top speed and high amps equals high torque (and of course higher production of heat).

Edit
I see your original point. You are not interested in torque but only on top power.
 
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CXRAndy

Guru
Location
Lincs
There us alot of mis marketing to circumvent the restrictions placed on ebikes. 250W could be peak or continuous power. Batteries are generally sold separately so a 250W motor could well be over volted to produce a 1000W. I found with my strength a motor with a capability of producing 250 W continuous is plenty for easy cruising
 
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