Q75 Hub motor

[Phil the drill]

Hi - anybody used one of these? Sorry if i'm duplicating a previous thread here, but i've done a quick search and it hasn't thrown anything much up.
I gather the motor has been around for 3 or more years and appears to be very light at 1.2Kg (quoted). I've heard these are made by Tongxin - Cute, but I'm struggling get any more details about them. I'm assuming they are geared, not a 'roller type' drive, and BMS battery say that it is capable of 40Nm torque - which appears pretty repectable for such a small motor.
I'm considering a new build on a light(-ish) hybrid I've had for many years and fancy using it as a simple light weight front hub unit on a 700c wheel. I live in a very hilly area (Cornwall) and do commute daily to work (about 9 miles each way) on both an ebike and my hybrid - so I can do it on an ordinary bike, but would just like to supplement it for the harder bits. I have become very frustrated with my 26v Panasonic mid drive bike (Sahel Pro disc) - it's such a pain to ride up steep rapidly changing gradients - you have to fight it for gear changes, losing all momentum gained riding down hill, and it forces to go so slooooowly uphill, it's like being assisted to push a bus uphill.....
Any how, I digress - Q75 front hub motor - 36v - please any helpful info much apreciated. Please post real experience if you have it, or if I've missed some giant thread somewhere a kindly re-direction would also be appreciated. Many thanks,
Phil

 

[Deleted member 4366]

I put one in an old steel-framed road bike. It's nothing to do with Tongxin. it's basically a Q100 with a smaller rotor and stator. the gears and clutch are the same. They're clones of Aikema motors.

It's light, but it has some negative points: It's sensorless, so won't work with the nice sine wave controllers. The Q100/Q85s are very sensitive about what controllers they want to work with when in sensorless mode, so you might have to try a few different controllers before you get one that works smoothly. I used the BMSBattery bottle battery with the controller in the base. It didn't work very well out of the box, but then I played with the P1 setting and got it OK (260 IIRC).

You can't expect much from such a tiny motor. It makes up a bit by spinning faster than most and using a high reduction ratio to get the torque. It's fine in the mid-range, but it wouldn't be my choice for steep hills. I was using 15 amps.

There's a new motor from Xiongda that only weighs 1.4 kg. I ordered a sample and I expect delivery any day soon, so I can give a review then. I think it might be closer to what you want than the Q75. It's probably cheaper. Delivery is probably cheaper too, and Xiongda provides a nice controller and LCD to go with it. IIRC, $69 + $50 for the controller and LCD + shipping. You can only get it as a bare motor, so you have to build it into a rim yourself. Email bonnie@xiongdamotor.com.cn if you want to order one. There are front and rear versions. I'm not recommending it because I haven't tried it yet. I trust them enough to take a punt on one. At $69, you won't lose much. The controller and LCD would cost you £100 in the UK.

 

[Phil the drill]

I put one in an old steel-framed road bike. It's nothing to do with Tongxin. it's basically a Q100 with a smaller rotor and stator. the gears and clutch are the same. They're clones of Aikema motors.

It's light, but it has some negative points: It's sensorless, so won't work with the nice sine wave controllers. The Q100/Q85s are very sensitive about what controllers they want to work with when in sensorless mode, so you might have to try a few different controllers before you get one that works smoothly. I used the BMSBattery bottle battery with the controller in the base. It didn't work very well out of the box, but then I played with the P1 setting and got it OK (260 IIRC).

You can't expect much from such a tiny motor. It makes up a bit by spinning faster than most and using a high reduction ratio to get the torque. It's fine in the mid-range, but it wouldn't be my choice for steep hills. I was using 15 amps.

There's a new motor from Xiongda that only weighs 1.4 kg. I ordered a sample and I expect delivery any day soon, so I can give a review then. I think it might be closer to what you want than the Q75. It's probably cheaper. Delivery is probably cheaper too, and Xiongda provides a nice controller and LCD to go with it. IIRC, $69 + $50 for the controller and LCD + shipping. You can only get it as a bare motor, so you have to build it into a rim yourself. Email bonnie@xiongdamotor.com.cn if you want to order one. There are front and rear versions. I'm not recommending it because I haven't tried it yet. I trust them enough to take a punt on one. At $69, you won't lose much. The controller and LCD would cost you £100 in the UK.

Hi,
Many thanks for prompt reply. that's just the kind of info I need.
I will have a look at the Xiongda you mentioned. I'm fine with lacing my own hubs, I've done that numerous times before so that will be O.K. As you say, at the quoted price there's not much to lose and it may well be worth a punt. I would also combine it with bottle battery. When I get round to it, I'll post some pics and feedback.
Many thanks,
Phil

 

[Phil the drill]

There's a new motor from Xiongda that only weighs 1.4 kg. I ordered a sample and I expect delivery any day soon, so I can give a review then. I think it might be closer to what you want than the Q75. It's probably cheaper. Delivery is probably cheaper too, and Xiongda provides a nice controller and LCD to go with it

Hi,
Thanks again for the info., but I'm afraid I can't find anything on Xiongda's website that seems to fit the description, all motors listed seem to be 2-3kg in weight. Do you have model or ref. no. for the motor and controller? It would be nice to know what I was asking for!
Many thanks

 

[topographer]

I'm afraid I can't find anything on Xiongda's website that seems to fit the description

http://www.pedelecs.co.uk/forum/threads/new-tiny-xiongda-motor.27981/

 

[Phil the drill]

http://www.pedelecs.co.uk/forum/threads/new-tiny-xiongda-motor.27981/

Many thanks.