Questions about a Bafang front hub build

[kaltsoplyn]

Questions about a Bafang QSWXK or Cute Q-100SX front hub build

Hi all and happy new year,

I decided to go forward with a bafang QSWXK 36V/250W front hub, 26" wheel build. I'll be ordering stuff from BMSbattery / ECITYPOWER or similar and I have a few technical and non-technical questions. Here goes:

1) regarding disc brakes: I've read that the QSWXK has to be laced with all spokes heads-out/butts-in on the disc brake side or else the caliper will interfere with the spokes. I suppose this is true for 160mm rotors, but is it also true for 185mm or 203mm rotors? For those of you with personal experience, is it laterally safe and stable to build a wheel all heads-out?

2) I'll be ordering the motor, sensorless controller, thumb throttle, charger and 36V/10Ah battery, say from the BMSbattery site. Does anybody know if these come with all necessary connectors? What type of extra connectors will I need?

3) are 13g spokes really necessary? I mean a steel fork can absorb some vibrations and 13g's will make the wheel stronger, but man are they rigid! Won't some quality 14g DT Swiss spokes cut it?

4) also, are torque arms necessary? If so, could they be substituted with, say, non-turn washers or something?

5) and a non-technical question: How probable would you think it is that such a large package is stopped/detained at the customs office? Am I looking at some 30% surcharge if it happens? The package will probably be sent with DHL (I would prefer to use EMS instead, but they charge literally double the price)

So, that's all for now. Any help will be greatly appreciated.

 

[Pedalo]

Ah I'm trying to get up to speed on this subject myself.

One thing I did read in a thread here was that 'version 2' of the SWXK motor is better for disk brakes than 'version 1'. I've no idea why but I would suggest trying to make sure you get a version 2 before you order.

 

[dan]

5) and a non-technical question: How probable would you think it is that such a large package is stopped/detained at the customs office? Am I looking at some 30% surcharge if it happens? The package will probably be sent with DHL (I would prefer to use EMS instead, but they charge literally double the price)

So, that's all for now. Any help will be greatly appreciated.

It is not a surcharge it is duty and VAT. Would the paying of legitimate import duty and VAT affect your buying decision ?

 

[kaltsoplyn]

It is not a surcharge it is duty and VAT. Would the paying of legitimate import duty and VAT affect your buying decision ?

Duty and VAT is, essentially, a surcharge, which I may or may not be called to pay.

To your question the answer is no.

As to whether I consider the current VAT and duty rates in my country (and the European union in general for that matter) a rip-off, is an entirely different subject.

 

[z0mb13e]

Duty and VAT is, essentially, a surcharge, which I may or may not be called to pay.

To your question the answer is no.

As to whether I consider the current VAT and duty rates in my country (and the European union in general for that matter) a rip-off, is an entirely different subject.

Off topic I know but did anyone anywhere ever (and by that I mean normal people, not the rich or politicians) agree that VAT or Duty was ever ok?

VAT doesn't add any value to what I am buying as far as I can see, it just makes it more expensive

 

[clv101]

Off topic I know but did anyone anywhere ever (and by that I mean normal people, not the rich or politicians) agree that VAT or Duty was ever ok?

VAT in the UK started (10%) in 1973. It was German invention and a requirement for joining the Common Market / European Union. VAT replaced the purchase or sales tax that was introduced in Oct 1940 on "luxuries" at 33.3% to raise revenue and curb spending on non-necessities in wartime. I expect most normal people thought it an okay idea in 1940. Of course after the war we were BROKE and again I expect most normal people recognised the government's need to raise revenue.

 

[Deleted member 4366]

I think I can help you because I've already bought a kit from BMSbattery. Your first question about the disk: 160mm is no good; 180mm should be a OK. One of mine (180mm) is clear by a couple of mm, the other can occasionally just touch one spoke as it goes round. I guess it depends on your forks and the size of the calliper. The spokes: The standard ones from BMSbattery whatever they are do the job. If you have problems in the future (unlikely), then you can start worrying about which spokes are ideal and get your wheel rebuilt. The connectors: You'll probably have to do something as it's unlikely that your battery connector (if you already have one) will match the controller. The throttle and motor connectors should fit, as should the pedelec sensor, but you need to check if the controller has an input for a pedal sensor. According to the info on their website, it doesn't, but often with these Chinese suppliers, the pictures and info are out of date. Best would be to e-mail them to check the latest situation. They are quite good at responding to e-mails now. If the controller doesn't have an input for a pedal sensor, you can get one from EV Assemble. Customs duty: I've bought loads of stuff from China and never had to pay any duty. Likewise, a lot of other people in this forum seem to have got away with it. I'm not aware of anyone that got caught, but it's by no meens certain and could change any day. Worth the risk IMHO. Anything from USA and you get caught every time - in my experience.

 

[kaltsoplyn]

Thanks for the info d8veh.

Now could someone explain this:

BMSbattery is apparently short on bafang QSWXK motors, so I asked about buying the Cute Q-100SX 36V/350W instead. My natural question was what happens with the 250W sensorless controller and if this too would have to be changed since the motor is now rated at 350W (although in their site they list no other sensorless controllers). The response was no, "The controller is enough for Q-100 motor. You needn't to change to 350W controller". How does this work out?

Generally speaking about the Cute Q-100SX, does anybody have any personal experience? Is it disc brake compatible? What is the PCD of the hub? Is routing the cables through the axle of the hub considered a significant drawback?

Thanks...

 

[Deleted member 4366]

According to the info on the BMSbattery website, it is disk brake compatible, which I guess means that it's got standard fixings. I read on the ES forum that Cute motors have more drag than the Bafangs when freewheeling, but how much? EV Assemble can provide the Bafang motor already laced to a rim, but when I asked them about it, I didn't get a reply. It might be worth asking them.
Regarding the 350w motor, the controller that they offer is bigger (much bigger) and more powerful to provide the current that the 350w motor needs.

 

[mechaniker]

please check the difference between serie 1 and serie 2 of the Bafang swxk motor´s

on serie 2 it is possible to fix diskbrake very easy

regards
frank

 

[Pedalo]

please check the difference between serie 1 and serie 2 of the Bafang swxk motor´s

on serie 2 it is possible to fix diskbrake very easy

regards
frank

Thanks for the pictures Frank. I'd read in a thread (probably one of yours) that series 2 are much better for disk brakes.

In general if a bike already has disk brakes, is it very likely to fit a type 2 motor? Or are there cases where it will still not fit?

 

[mechaniker]

Thanks for the pictures Frank. I'd read in a thread (probably one of yours) that series 2 are much better for disk brakes.

In general if a bike already has disk brakes, is it very likely to fit a type 2 motor? Or are there cases where it will still not fit?

Hi,
yes, another problem is the other side,
if you have a fork with axle grip in the middle, you can´t fix a swxk. You need the grip for the axle on the innerside of the fork.

I think the picture make clear what i mean.

regards
frank

 

[kaltsoplyn]

please check the difference between serie 1 and serie 2 of the Bafang swxk motor´s

on serie 2 it is possible to fix diskbrake very easy

regards
frank

Thank you Frank. However, to the best of my knowledge, no site I've found declares if it's a series 1 or a series 2 motor they are selling. Given the usual communication breakdown, I doubt if someone will give you a straight answer even if you ask the straight question. Even if they do, they can still send you the wrong one!

 

[mechaniker]

Thank you Frank. However, to the best of my knowledge, no site I've found declares if it's a series 1 or a series 2 motor they are selling. Given the usual communication breakdown, I doubt if someone will give you a straight answer even if you ask the straight question. Even if they do, they can still send you the wrong one!

i only sell series 2 ;-) i sell with hall or without hallsensor the swxk depend on what the customer want.
But sorry, i only sell to company´s, but at time i think about open my shop also for everyone, maybe ......

regards
frank

 

[Pedalo]

i only sell series 2 ;-) i sell with hall or without hallsensor the swxk depend on what the customer want.
But sorry, i only sell to company´s, but at time i think about open my shop also for everyone, maybe ......

regards
frank

I'm sure you'd get plenty of customers here, me included!

I would also think perhaps that most individuals would be prepared to pay a few $ more than others are charging to have the added confidence they are getting the right motor.

 

[Deleted member 4366]

Pedalo, If you're happy to pay a bit more, why don't you buy the Sunlova kit at £400. You get the disk brake 250w motor laced to a 26" wheel, battery, rack, controller, throttle and pedal sensor. All the connectors fit. You can specify a left hand pedal sensor, if theres, no room behind your chainwheel for the rather thick one they supply, or you may need a longer BB spindle, but, if you want to keep a tripple chainwheel (unnecessary when motorised), you'll definitely need the LH sensor. As Frank says, The hub will catch on your forks if you have centre mounted drop-outs - as I found out on my £15 bike, although the much larger 35w BPM motor fitted perfectly!

 

[Pedalo]

Pedalo, If you're happy to pay a bit more, why don't you buy the Sunlova kit at £400. You get the disk brake 250w motor laced to a 26" wheel, battery, rack, controller, throttle and pedal sensor. All the connectors fit. You can specify a left hand pedal sensor, if theres, no room behind your chainwheel for the rather thick one they supply, or you may need a longer BB spindle, but, if you want to keep a tripple chainwheel (unnecessary when motorised), you'll definitely need the LH sensor. As Frank says, The hub will catch on your forks if you have centre mounted drop-outs - as I found out on my £15 bike, although the much larger 35w BPM motor fitted perfectly!

Seems like a very reasonable question. The only reason I want to buy a motor seperately is that I only actually need the motor (though I will also need a 700C wheel rim & spokes). I already have a spare controller, throttle & battery. I've also got my own ideas about what to do with the battery so don't need the rack etc.

 

[Deleted member 4366]

Sunlova do ready-made 700c wheels. I've found them very accomodating. I'm sure if you ask them nicely, they may sell you just he bits you want. BTW, I see that hey have changed the pedal sensor to the common type, so they must also have changed the controller, and that handlebar consul looks new too.
http://www.sunlova.com/Detail.aspx

 

[Andrew harvey]

Sunlova keep spares in stock and are normally happy to just sell them.
The handlebar controller shown works really well, doing away with the usual problem of pedelec systems, .ie. the all or nothing power output. Using one of these I can get 80 mile range on their battery pack, lots of pedalling, but I like to ride a bicycle as a bicycle.