2 Speed Xiongda hubmotor

Chalo said:
donn said:
What are the odds that the Xiongda 2-speed is really intended for use with normal wheels, like 26" to 700C/29" ? It's a parameter I have wondered about - manufacturers are usually silent on the subject of the internal gear ratio, am I right?

Reduction gear ratios are usually 1:5 or close to it. Manufacturers can and do make different windings with higher or lower kV for different size wheels, but I know of none who make different gear reductions in the same hub for different wheels. For this reason, such hubs make the same maximum torque regardless of winding, and the same torque at a given heat load regardless of winding. So in a larger wheel, you get less push and more heating.

To get equal performance from a bigger wheel, you need a bigger hub.

So - not to put too fine a point on it, but everyone making hubs for bicycle wheels, essentially is making them for more or less the same size of wheel. Wonder what size of wheel that is?
 
donn said:
everyone making hubs for bicycle wheels, essentially is making them for more or less the same size of wheel
The point is, if more torque is needed than what the designer intended to deliver

going to smaller wheels is a relatively easy way to get that

without going to a stronger motor

which may not even be legal in many jurisdictions.

 
Ask Bonnie for a motor according the week size, XD makes them for all sizes.
700c, 28" and 29" are just different tires, they use exactly the same rim size (622 millimetres diameter), the total diameter is only slightly different, according the different tires (race bike, city bike, MTB.
This doesn't have a huge influence on the torque.
With the 2-speed motor the 1st gear will give high torque and low speed and the second gear will act like a "normal" 201rpm spec hub motor with comparable power rating.
 
Can't we just ask for the motor rpm we'd like? I'm planning to use this on a very light build, 27.5inch tires/wheels, was thinking of asking Bonnie for 24"? Is the 48v 350w version better than the 48v 250w?
 
knutselmaaster said:
Be careful, the front motor for disc brake is 10mm wider, so 110mm width.
On a front suspension, it generally doesn't fit.

So I found a CF front MTB fork 29er that is 110mm wide x 15mm, seems good yet I'm not sure of the 15mm part?

The kits come with brake motor kill switches that can also be used with cable based brakes, right? There are some light cable based non hydraulic disc brakes that look interesting.
 
The 15 mm, as you may or not know, is the size axle. Hopefully the motor has the same arrangement.
 
quattro74 said:
So I found a CF front MTB fork 29er that is 110mm wide x 15mm, seems good yet I'm not sure of the 15mm part?

110 x 15mm fork is a through-axle fork. The only hub motor I know that will work with it is Grin's All Axle motor.

Coincidentally, the Grin All Axle motor is a much better choice for a 29" wheel.
 
Thanks Chalo,

I really want to use this 2 speed motor though. If there is no adapter for the front hub motors to work with this hub motor then I will have to direct my attention rearward.

Regarding wheel rebuilds and lacing, does it matter If I buy a 'front' wheel to rebuild for a rear hub motor? I'm looking at buying some Mavic Allroad Elite UST wheels, seems a great way to deal with tires/punctures. It is cheaper to buy two fronts.
 
quattro74 said:
Regarding wheel rebuilds and lacing, does it matter If I buy a 'front' wheel to rebuild for a rear hub motor? I'm looking at buying some Mavic Allroad Elite UST wheels, seems a great way to deal with tires/punctures. It is cheaper to buy two fronts.

Most new production rims are tubeless compatible. Mavic rims are overpriced, crack prone, and rated for much lower spoke tension than others. I recommend against them.

Don't buy an entire wheel if all you want is the rim. Be sure to buy a rim with the same number of spoke holes as the hub. For hub motors, usually that's 36, but sometimes 32 or even 28.

If you use tubeless tires with sealant, you will be spending more time fooling with your tires than if you simply replace tubes as necessary. The main advantage is that you might be able to choose the places and times you work on your tires. The main disadvantage is that it's very messy. Plus you'll need an air compressor or a special accumulator to set the tire bead.

In my opinion, tubeless is best for goathead-strewn hellholes, or for weekend warrior dads who have only a small specific window of time in which they can ride. Otherwise, it's just more time, more trouble, more equipment, and more cleanup. Your tires will gradually get heavier and heavier as they transform into gross-out cinema special effects.

mountain-bike-tubeless-tire-sealant-check-and-removal-tech04.jpg
 
My experience is that tubeless is an advantage only with foam inserts (see Cush Core).

And yeah, shop for rims. You don’t want to buy complete wheels, with hubs that you won’t use, spokes that will be the wrong length, and a lacing job that you will have to dismantle. All this can pay for much better rims, spoke and nipples.

For lacing a hub motor, you are looking for a heavy rim, thick and robust. Not exactly the UST kind, that are usually light weight and thin, unless you are willing to pay the cost of carbon UST racing rims. With Cush Core kits, you can build tubeless with many strong rims that are not UST rated anyway. Just make sure that they are welded (not pinned), and wide enough. Check with unicycle or trial specialty dealers, for most of them have a choice of very tough rims, and 36h is not yet obsolete for them.
 
Thanks Guys,

Yeah, where I live I can't walk to the mailbox without getting a goathead in my shoe, that is pavement the whole way... So Mavic rims/spokes aren't strong enough for this Xiong Da 2 speed hub motor? Maybe just the Carbon ones? I'd like the Simplicity of the UST, ease of tire changes/repairs. I do want tubeless. I think btw that this motor has 24 holes for spokes? The UST system doesn't need a compressor, lol. If I could keep UST system and go stronger, lighter, cheaper sure.. I'm doing more research.

Looks like this XD Hub motor has 19 per side, so 38
 
quattro74 said:
Looks like this XD Hub motor has 19 per side, so 38

No, surely not. It's 36.

You won't find faddish or proprietary system rims in 36 hole these days. And due to supply shortages, you may have a difficult time finding any 29", 36 hole, tubeless ready rims at all.

My advice is get a normal rim that won't fight you when you're installing or removing a tire, and put sealant in the tube instead of the tire. That way when it turns into cheese curds, you just replace the tube.
 
Available now DT Swiss HX 531 29er 36h at wheelbuilder.com. It is a UST lightweight mtb racing rim. It is very stiff but thin hard alloy 30mm wide, meaning it is very resistant to dent or deform, but it could crack on a hard hit.

I believe the Stans no Tube MK3 rim is also available now in 29er 36h. Cheaper, narrower rim that can be ordered direct at Stans no Tube website.
 
Well thanks again,

Food for thought. As far as 'Normal Rim' I think I threw that out when I decided to go with the XD 2 speed hub, lol.

I will look at those rims and if they can take UST tires then I will seriously consider them. I think the UST tires are easy to remove and install, or is that just on UST rims? I don't think a Mavic rim is the way to go for a hub motor rebuild. The ones that 'might' be able to take normal steel spokes are 24 spoke rims. Plus they are expensive.
 
No tubeless tires are easy to install or remove; let go of that illusion and you'll be a lot happier in the long run.

Sealant works in tubes just as well as it works in naked tires.
 
Yeah, rather than running a tube in a tubeless I'll keep it handy incase I get a big gash. It will be nice to have the easiest tires to field change, put a tube in, Mavic UST tires on a wider wheel is supposed to be stupid easy. I won't know till I try. I think I know which wheel to buy and lace up. For a light build should I go 14 gauge spokes? Or will an e-bike need 12 or 13 gauge at a minimum?
 
quattro74 said:
For a light build should I go 14 gauge spokes? Or will an e-bike need 12 or 13 gauge at a minimum?

Only use thicker spokes if you want the wheel to be weaker and to require more maintenance.

My default with hub motor builds is to use 14-15ga (2.0/1.8mm) spokes in a cross-one pattern, with washers under the spoke heads if necessary to prevent spoke heads getting buried in the flange.
 
Thanks Chalo,

14/15 spokes are 14G at one end and 15G at the other? thicker end at the motor? Spoke gauge is like wire gauge right? higher is thinner? I'm such a noob.
 
quattro74 said:
Thanks Chalo,

14/15 spokes are 14G at one end and 15G at the other? thicker end at the motor? Spoke gauge is like wire gauge right? higher is thinner? I'm such a noob.

Yes, spoke gauge is wire gauge, or an approximation of wire gauge that's actually a metric diameter. 14-15ga spokes are "double butted", so they're 2.0mm on each end and 1.8mm in the middle. 14-16, 14-17, and 15-16ga spokes are also double butted. 13-14ga spokes are single butted, meaning they're 2.3mm at the elbow and 2.0mm down the rest of the spoke.

There are some "triple butted" spokes (a useful misnomer) that have for instance 13ga elbows, 15ga shanks, and 14ga threads.
 
quattro74 said:
Thanks Chalo,

14/15 spokes are 14G at one end and 15G at the other? thicker end at the motor? Spoke gauge is like wire gauge right? higher is thinner? I'm such a noob.

Just a spoke fyi, usually butted spokes are stronger for the weight, as they're drawn thru a die which aligns the metal grain, and meant to have the highest strength to weight ratio when grams count. Even if you're not worried about gram savings, it's kind of the hallmark of quality stainless non plated spoke. Part of why they use such huge spokes on cheap hub motor wheels is to try to make up for the inferior metal they start from.
 
Voltron said:
usually butted spokes are stronger for the weight, as they're drawn thru a die which aligns the metal grain, and meant to have the highest strength to weight ratio when grams count.

That's really, truly not the point of butted spokes.

The reason for butted spokes is to reduce their average cross-section so that they'll stretch more under a given static spoke tension. More stretch means a wheel can take more load before spokes go slack. A slack spoke is the same as a missing spoke for the purposes of supporting the rim.
 
Thanks Guys,

14/15s sound good to me, stainless, black to match the hub. Any brand that you're partial to?
 
quattro74 said:
14/15s sound good to me, stainless, black to match the hub. Any brand that you're partial to?

I prefer DT Swiss or Sapim, without any preference except for price and availability. I also use Marwi and Wheelsmith without qualms.
 
Thanks,

Now the hard part seems to be getting the 135mm hb motor to fit a suitable frame. Most frames out there for road bikes are 130mm QR, at least the vintage ones I'm looking at. Seems if the frame is steel it isn't a problem to spread the frame slightly. What about Titanium?
 
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