Xiongda YTW-06 front hub motor into Norco Indie 3

[Benchie]

Hello Everyone,

I’ve lurked here for a few months, reading many threads about various conversions in order to help plan my own build. Having now finished it, I thought I’d post the results on the basis it might be informative for others.

The donor bike is a Norco Indie 3 (2014) which has covered about 1500 miles. It’s a hybrid style bike with flat bars and 700C tyres. My normal fun ride is roughly 30 miles round trip, but miles 24 to 28 are a fairly constant incline that detracts from the pleasure of the rest of the ride. My thoughts were that a lightweight hub motor could be used to aid on the inclines without detracting from the normal pedal power on flatter sections (so a primary concern was not to add too much weight). Inspired by threads written by d8veh and AWOL, I decided to go with the small Xiongda YTW-06 as a front hub conversion.

I've taken a few photos of the build which I can post if I can work out how to! The finished article appears as my avatar. The bike weighed 12.1kg before I started, and the finished conversion came in at 16.5kg all up with a 36v 10S4P 11.6 Ah battery. Total cost excluding the donor bike worked out at £358 which I don't think is too bad.

 

[awol]

Looks a good stealthy conversion.
Is your battery in the saddle bag? I wanted to use that idea but being too short I can't raise the seat high enough.

 

[Benchie]

Looks a good stealthy conversion.
Is your battery in the saddle bag? I wanted to use that idea but being too short I can't raise the seat high enough.

Hi awol, yes the battery is in the bag along with the controller. I know what you mean about the height required to fit this bag, and I only just managed it with about 30mm clearance to the rear tyre.

Which raises a question about how waterproof these bags are. I imagine it will collect quite a bit of water from the rear tyre and I'm slightly concerned about the controller and connections. Still need to think some more about that.

 

[Jonah]

After deliberating for some time I am on the verge of ordering one of these, but with a 48v setup. How do you rate the assist level on your hilly section?

 

[Benchie]

I've only done few miles on the bike since finishing it on Friday night (the weekend snow seems to have dissuaded me!) so can't really say how it deals with hills. I'll try a little harder this weekend and let you know.

I didn't know that Xiongda offered a 48v version. Is this the same motor but running a different controller, or are the windings different? Incidentally, I think another forum member has recently ordered an updated version that includes hall sensors. My motor was built in November, and pretty sure it is sensorless.

A couple of pictures of the end product...

 

[Nealh]

A very nice clean build, you have to look twice to see the it is a front hub motor.
The only issue I see (though you may sorted it now) is to use a slim Velcro band and just secure the motor cable to the fork.

 

[awol]

Nice neat battery.
What hydraulic brake sensors have you used?

 

[Nealh]

You can confirm if you have a sensored hub or not by how many pins the motor wire has or the motor wire connection to the controller. 3 pins NO or 8/9 pins YES.

 

[Benchie]

A very nice clean build, you have to look twice to see the it is a front hub motor.
The only issue I see (though you may sorted it now) is to use a slim Velcro band and just secure the motor cable to the fork.

The motor cable is secured to the fork at the same tie down point as the brake line, but there is quite a bit flapping around in the breeze. Thanks for the suggestion of using a Velcro strap. That's a great solution to still allow easy wheel removal for puncture repairs!

 

[Benchie]

Nice neat battery.
What hydraulic brake sensors have you used?

The brake sensors are the standard generic stick on parts. I simply removed the 3M tape, turned the sensor body over 90 degrees to allow it to fit between the buttresses on the master cylinder, and epoxied in place.

 

[Nealh]

Now enlarged I see the cable tie, on my front hub I Velcro high and low on the fork.

 

[jens]

Hi Benchie, can you share some more about the support this tiny motor delivers uphill? Or riding experience in general?

 

[Benchie]

Hi Benchie, can you share some more about the support this tiny motor delivers uphill? Or riding experience in general?

Hi Jens, no problem. First thing to say is that I have no point of reference having never ridden an ebike before starting this build. But overall, it's a transformational change compared to riding unassisted!

Firstly, the performance up hills is absolutely fine for me. I weigh 90kg and the converted bike weighs 16.5kg, so there is a fair bit of weight to pull up a hill. My normal routes are more long inclines, with a 3 mile constant climb of about 150 metres in height. So not too steep. Some short parts are much steeper, and it still climbs these OK and I don't think I'll find a hill that it won't manage.

In terms of general riding, I now completely understand the point that d8veh made about the lag between pedal input and the reaction of the motor / controller. It feels like a 1 second delay which I soon got used to, but which also made me thankful that I installed a brake cut-off. Low speed manoeuvres, especially near to busy traffic junctions would be a bit worrisome without.

I tend to ride with PAS assist set to 2 on the flat, and then use 3 or 4 on inclines. The range is quite impressive, with a 30 mile trip with 500m of altitude gain only using about 40% of my 11.6 aH battery. The battery is a 10S4P configuration made from Panasonic NCR18650PF's. Voltage at start of journey = 41.8v and at the end was down to 38.1v, and the voltage readout is clearly a better indicator than the 5 bar readout (which was just dropping from 5 to 4 at the end of a 30 mile trip).

There is a bit of extra resistance running with no assistance (compared to the original non converted condition). That's no surprise as the bike weighs an extra 4.5kg and I increased the tyres from 38c to 47c (which also transforms the ride quality).

In terms of speed, my controller and motor is set up for the UK legal 15.5 mph. Not surprisingly, it makes cruising at this speed on the flat much easier, whilst the effect of drag on higher speed downhill routes is negligible.

So, overall I'm quite pleased. I wanted a small lightweight motor to add some assistance rather than an electric motorbike. I think you mentioned that your motor is a later version with hall sensors and a KT controller, which should make a nice difference in terms of response. I'd love to hear how you get on.

 

[awol]

First thing to say is that I have no point of reference having never ridden an ebike before starting this build. But overall, it's a transformational change compared to riding unassisted!

When I built a bike with this motor, I thought that although it doesn't have the torque I was used to, if this was the first assisted bike I had ridden I would be very pleased with it especially given it's small size.
I am still tempted to transfer it to a bike for me to commute daily over summer.

 

[Deleted member 4366]

I find the torque amazing for such a small motor. It seems to me to be about the same as any other 250w hub-motor bike that you can buy in a shop.

 

[Jonah]

I’ve got the Sensored version being built into a wheel this week. Hopefully get it installed next week and let you know my impressions.

 

[jens]

Great, thanks for sharing!
Hopefully all parts will be available for order again after Chinese holiday ends.
I will order from Bonnie / Xiongda directly

• 1 rear sensored YTW-06 motor
• KT Brushless Controller
• KT LCD5 Control Panel
• PAS & Controller Box

As battery I'll order this 1.5kg 7AH Bottle battery, as it seems to be the most lightweight option.
If you see any potential improvements, I'm always grateful

 

[Benchie]

The link suggests that the 7aH battery is in a 10S2P configuration? If so it suggests that the cells are 3500 mAh each which is pretty high, and the associated max discharge rate may be an issue. I'm not sure what the KT controller is rated at, but I suspect at least 12 amps at peak. Which means each cell needs to be able to deliver 6 amps. Do you know what type of cell is used in that battery?

 

[jens]

It says the 36v/7ah battery uses Sanyo GA 3,7 V 3500mah cells. So 3.5 amps, not 6.

• 36V 5.2ah: LG 3,7V 2600mah
• 36V 5.8ah: LG 3,7V 2900mah
• 36V 6.4ah: LG 3,7V 3200mah
• 36v 7ah: Sanyo GA 3,7 V3500mah

I understand absolutely nothing about electro physics or what you may call it, to be honest.

 

[Benchie]

I found the spec sheet for the Sanyo NCR GA cell which states a 10 amp max discharge current, so with 2 cells in parallel you can in theory draw a maximum of 20 amps. If your controller is rated at 12 amps then each cell would need to be capable of supplying 6 amps. Which these GA cells clearly can. The 6 amp discharge curve is shown in green in the chart below.

The only thing to be aware of is 'voltage sag' where the supplied voltage will drop when large discharge currents are required. This might become an issue if you are going up a hill, pulling maximum current, when the battery is 75% discharged. The drop in voltage might trigger the controller cut off (which will be at about 31 volts), so you might have to ride around this using lower PAS settings as the battery depletes.

What sort of range are you looking for?