700c rim with 12g spoke holes and 12 guage spokes?

[Monsoon]

I'm doing a MAC hub motor build, and i'd down to the rim and spoke selections.

I want to find a rim with 12 gauge spoke holes to get a closer match to the hub spoke hole size which is actually 11 gauge.

Oh, and can someone link a manufacturer or two who carry 12 gauge stainless spokes?

 

[wesnewell]

What size tire you plan on using? That should determine rim width. For tires over 2.0" (51mm) I consider 1/2 the tire diameter or larger best for better traction and stability.
http://sheldonbrown.com/tire-sizing.html#width
Wide rims are hard to find, especially for 700c, but it's well worth it. The only way I found one in 26" was to order a complete wheel and strip the rim off for use on my hub motor. I use these. Solid as a rock.
http://www.weinmanntek.com/Products/FREESTYLE/DH39.htm
Good luck finding anything similar in 700C.

 

[Drunkskunk]

JRH, a member here, who owns http://holmeshobbies.com/ is the best source of spokes I've found, and he can get 12 gauge.

But I would strongly advise against 12g. They are too stiff for a good wheel build, and you're likely to crack the rim or actualy brake more spokes because they are too stiff to propperly distribute the load.
You might try a 13/14 Single butted spoke, with or without spoke washers, or a 14 strat gauge with washers. you'll have a much stronger, resilient wheel with propperly sized spokes.

 

[cal3thousand]

Going with thick spokes you better get a STRONG rim to handle the tension required for the stretch needed. I would go with a Moped rim if you are insistent on using thick spokes.

Otherwise, a downhill rim at the very least.

(BTW, your motor will be happier if you stay away from the 700c/29er wheels. 26" is the largest that I go now. If you are going 700c because of the speed, just go for more voltage in a 26" or 24" instead. (26" parts being MUCH more prevalent makes things easier)

 

[bowlofsalad]

(BTW, your motor will be happier if you stay away from the 700c/29er wheels. 26" is the largest that I go now. If you are going 700c because of the speed, just go for more voltage in a 26" or 24" instead. (26" parts being MUCH more prevalent makes things easier)

Could you please deeply elaborate?

Maybe OP is choosing a 700c rim because his frame accomodates 700c (622).

 

[cal3thousand]

(BTW, your motor will be happier if you stay away from the 700c/29er wheels. 26" is the largest that I go now. If you are going 700c because of the speed, just go for more voltage in a 26" or 24" instead. (26" parts being MUCH more prevalent makes things easier)

Could you please deeply elaborate?

Maybe OP is choosing a 700c rim because his frame accomodates 700c (622).

Sure, unless the frame that I am using CANNOT use smaller wheels, I will tend to stay away from 700c. Only case I see here, are 700c frames with non-disc brakes and frames with BB that are too low to begin with. I still have a 700c bike that I'm getting rid of now (It was my noob bike).

If a frame is 700c and disc, I would drop it down to 26". (This is for ebikes only). Reason being is that a motor is better off when the effective gear ratio that it has to drive is smaller and the motor is allowed to spin. This creates less heat and waste.

Basically, speed should not be the determining factor for selecting 700c wheels. One should not say "I am choosing a 700c wheel, because my bike will go faster with it." That same person should stick with a 26" wheel and volt up to the desired speed.

You'll here it often on this site from the highly experienced (like Dogman): "Gear down and volt up"

 

[Monsoon]

This has nothing to do with wanting to go fast. in fact I chose the second slowest winding on the MAC hub.

I have the largest size frame made for a GT transeo. In fact it's so big that I had to get a stem with a shorter reach, because the factory one was too long, and i'm 6'2".

That bike with the 35's that I have on it, look almost pathetic and scrawny. There's just no way i'm putting a 26" wheel on there.

As far as the rim goes, i'm just going to go with the Weinmann DH-39 mentioned in another thread of mine here. It comes with 12 gauge eylets on it, and i'll go with one of the links wesnewell gave me for the spokes.

 

[bowlofsalad]

It's an interesting discussion, I don't know about how larger and smaller wheels effect efficiency, but I do know that larger diameter wheels improve comfort of the ride itself. I feel like this could be a similar discussion about suspension and how it effects efficiency. But frankly, ride comfort is a pretty tremendously important concept in my mind. If I had to sacrifice a watt hour per mile or two for gains in ride comfort or a smooth ride in general, I'd gladly take the hit.

http://ebike.ca/simulator/ Says that you are getting slightly better efficiency when using a 700c wheel at 20mph compared to a 26" tire. The efficiency gain isn't something to write home about when using a 700c wheel according to the linked simulator, but it's still paints an opposing story to your perspective.

Do you have any sources for efficiency gains or losses for wheel size? Perhaps you have ridden the same bike in an indoor track at the same speeds with a watt meter and temperature probes. I'd like to see a video of that test laying out the results of such a test between various wheel sizes.

I suspect that ideas like weight, drag (aerodynamics) and rolling resistance play a wildly larger roll in how far you go per watt hour and how much energy it will take to get you to speed and to maintain speed.

The argument about volting up and gearing down might be a expensive one. While going between voltages like 36 and 48 probably isn't going to cost a whole bunch more, using some voltages (typically anything above 72 it seems) is likely to be far more costly. In other words, if I was going to aim for something around 84v to get a similar speed (This is 16" wheel vs 700c wheel) and evidently lower efficiency (according to mentioned simulator) I'd likely end up spending a lot more on various parts. Much of the ebike world seems geared for voltages between 36 and 48. While I would have a larger battery capacity, that battery will cost more.

Personally, I have been using 26" wheels, but I am working towards using larger wheels solely because of the comfort idea. 622x60 big apple tires sound nice.

 

[cal3thousand]

This has nothing to do with wanting to go fast. in fact I chose the second slowest winding on the MAC hub.

I have the largest size frame made for a GT transeo. In fact it's so big that I had to get a stem with a shorter reach, because the factory one was too long, and i'm 6'2".

That bike with the 35's that I have on it, look almost pathetic and scrawny. There's just no way i'm putting a 26" wheel on there.

As far as the rim goes, i'm just going to go with the Weinmann DH-39 mentioned in another thread of mine here. It comes with 12 gauge eylets on it, and i'll go with one of the links wesnewell gave me for the spokes.

Then you certainly have the right idea and chose the 700c wheels for its other virtues. Pairing it with a slow wind motor is a great way to go.

Does the DH-39 come in a 700c?

It's an interesting discussion, I don't know about how larger and smaller wheels effect efficiency, but I do know that larger diameter wheels improve comfort of the ride itself. I feel like this could be a similar discussion about suspension and how it effects efficiency. But frankly, ride comfort is a pretty tremendously important concept in my mind. If I had to sacrifice a watt hour per mile or two for gains in ride comfort or a smooth ride in general, I'd gladly take the hit.

http://ebike.ca/simulator/ Says that you are getting slightly better efficiency when using a 700c wheel at 20mph compared to a 26" tire. The efficiency gain isn't something to write home about when using a 700c wheel according to the linked simulator, but it's still paints an opposing story to your perspective.

Do you have any sources for efficiency gains or losses for wheel size? Perhaps you have ridden the same bike in an indoor track at the same speeds with a watt meter and temperature probes. I'd like to see a video of that test laying out the results of such a test between various wheel sizes.

I suspect that ideas like weight, drag (aerodynamics) and rolling resistance play a wildly larger roll in how far you go per watt hour and how much energy it will take to get you to speed and to maintain speed.

The argument about volting up and gearing down might be a expensive one. While going between voltages like 36 and 48 probably isn't going to cost a whole bunch more, using some voltages (typically anything above 72 it seems) is likely to be far more costly. In other words, if I was going to aim for something around 84v to get a similar speed (This is 16" wheel vs 700c wheel) and evidently lower efficiency (according to mentioned simulator) I'd likely end up spending a lot more on various parts. Much of the ebike world seems geared for voltages between 36 and 48. While I would have a larger battery capacity, that battery will cost more.

Personally, I have been using 26" wheels, but I am working towards using larger wheels solely because of the comfort idea. 622x60 big apple tires sound nice.

Going to the larger wheel for comfort is fine. But my suggestion is that no person choose the larger wheel for a higher top speed.

The OP effectively 'geared down' by choosing a slower wind (and a geared hub motor spinning much faster vs a DD for the same wheel speed). I have toyed with different wheel sizes and will personally stick with the smaller wheels and going to 26" as a comfort size.

BTW, did you make sure to back the throttle off from the 700c wheel to match the 100% throttle speed of the smaller wheel while pegging everything else? Here's a simulation with a DD motor, same battery, 700c vs 20", throttle has been backed off of the 700c to match the WOT speed of the 20" wheel. As you can see, the efficiency of the smaller wheel is actually better at 26.3mph even though the 700c will have some more 'top end' and will eventually reach 31.3mph if given WOT.

 

[bowlofsalad]

Yes, I did. But what I am looking at is coming up with different results than your own. After lots of playing around with the simulator, I think I found the reason as to why your results differ from my own.

I don't entirely understand the reasoning for it, but when I use full recumbent instead of mountain bike in vehicle parameters, I come up with a very different pictures than yours depicts. I don't know if it's a glitch, but I am sure there is more to it. The lower the drag, the higher efficiency gains with a larger wheel compared to a smaller wheel.

 

[Monsoon]

@cal3thousand, yes the DH-39 does come in a 700c rim. that's the only way I would use it, since as I said the 700c rims I have on their with the 35mm tires look absolutely puny on that frame.
26" rims would look really bad on it.

 

[Chalo]

700c rims flex more than 26" rims, which makes it more important to use spokes that have good elasticity at tolerable tension.

The heaviest I have used on 700c rims were Wheelsmith 13/14ga single butted spokes on a 1000g 29" mountain unicycle rim (a very stiff rim that could tolerate high tension). Those were reasonably reliable, but suffered a couple of breakages while 14/15ga spokes on comparable wheels in my collection of bikes have not.

 

[Monsoon]

What size tire you plan on using? That should determine rim width. For tires over 2.0" (51mm) I consider 1/2 the tire diameter or larger best for better traction and stability.
http://sheldonbrown.com/tire-sizing.html#width
Wide rims are hard to find, especially for 700c, but it's well worth it. The only way I found one in 26" was to order a complete wheel and strip the rim off for use on my hub motor. I use these. Solid as a rock.
http://www.weinmanntek.com/Products/FREESTYLE/DH39.htm
Good luck finding anything similar in 700C.

I meant to reply to this the other day, but I also wound up looking at some pre-built wheels to do that. In the end, i'm glad I called the guys at Velocity, because they spent time on some of the wheels I was interested in, and eventually steered me to the NoBS rim, which looks like it's going to do a fine job with the spokes you linked for me.

 

[Monsoon]

(BTW, your motor will be happier if you stay away from the 700c/29er wheels. 26" is the largest that I go now. If you are going 700c because of the speed, just go for more voltage in a 26" or 24" instead. (26" parts being MUCH more prevalent makes things easier)

Could you please deeply elaborate?

Maybe OP is choosing a 700c rim because his frame accomodates 700c (622).

Sure, unless the frame that I am using CANNOT use smaller wheels, I will tend to stay away from 700c. Only case I see here, are 700c frames with non-disc brakes and frames with BB that are too low to begin with. I still have a 700c bike that I'm getting rid of now (It was my noob bike).

If a frame is 700c and disc, I would drop it down to 26". (This is for ebikes only). Reason being is that a motor is better off when the effective gear ratio that it has to drive is smaller and the motor is allowed to spin. This creates less heat and waste.

Basically, speed should not be the determining factor for selecting 700c wheels. One should not say "I am choosing a 700c wheel, because my bike will go faster with it." That same person should stick with a 26" wheel and volt up to the desired speed.

You'll here it often on this site from the highly experienced (like Dogman): "Gear down and volt up"

Cal, as I mentioned in the other thread the smaller wheels would have looked ridiculous on the huge frame of my bike. I would gladly have done that if I could, especially since there were far more beefy rims in a 26" size at pretty much every place I checked.

 

[liveforphysics]

Yes, I did. But what I am looking at is coming up with different results than your own. After lots of playing around with the simulator, I think I found the reason as to why your results differ from my own.

I don't entirely understand the reasoning for it, but when I use full recumbent instead of mountain bike in vehicle parameters, I come up with a very different pictures than yours depicts. I don't know if it's a glitch, but I am sure there is more to it. The lower the drag, the higher efficiency gains with a larger wheel compared to a smaller wheel.

At light loads, core loss is exceeding copper loss (remember, when starting at no-load current for a given RPM, you've got negligible copper loss, so nearly all the inefficiency is a result of core losses). Larger wheel diameter dropping motor RPMs reduces core loss while increasing copper loss, but this puts them closer into balance (peak efficiency will always be the balance of the two types of losses).

These core losses are actually pretty high on many of these hub motors. I think Justin determined it was predominately hysteresis rather than eddy loss. This means somebody should do an optimized minimum tooth iron stator profile, stamp it from exotic ultra-high flux capable cobalt (and possibly radially grain oriented) nickel and whatever else they did on the F1 KERS motor's lamination material, and do a hat-pin bus-bar slot "hat-pin" wound winding, maybe in pure silver wire. Space the windings hat-pin end-turns to have gaps like a hundred little folded copper bar heat-sinks, and some fins on the rotor that flow it though it and over them. I would think iron losses could be perhaps 1/4rd if you were only looking for a motor that saturates at a pretty low torque level compared to the guys who like to run 10,000w, but plenty for most <1kw kick-ass on a roadbike assist motors. Silent. Direct drive and durable and reliable and weather-proofed with exotic connections and titanium axles and beautiful forgings and ceramic bearings. Some day, and likely not too far off, Shamano (or some uber-premium component company) is going to make a "dura-ace" level direct drive assist hub. I would personally buy that for my roadbike, even if it cost ~$2500 or whatever. If it weighed just a pound or two, and gave like ~1kW asssit max, but when sustaining like 25mph 500w output it had perhaps ~>95% motor efficiency, maybe it's even >98% which would enable it being a thin-gap-ques design.

 

[full-throttle]

optimized minimum tooth iron stator profile..
exotic ultra-high flux capable cobalt..
radially grain oriented..
hat-pin bus-bar slot "hat-pin" wound winding..
pure silver wire..
titanium axles..
ceramic bearings..

What's the title of the thread again?? :?
Luke is on drugs

 

[bowlofsalad]

I think hes doing satire.

 

[Monsoon]

At light loads, core loss is exceeding copper loss (remember, when starting at no-load current for a given RPM, you've got negligible copper loss, so nearly all the inefficiency is a result of core losses). Larger wheel diameter dropping motor RPMs reduces core loss while increasing copper loss, but this puts them closer into balance (peak efficiency will always be the balance of the two types of losses).

These core losses are actually pretty high on many of these hub motors. I think Justin determined it was predominately hysteresis rather than eddy loss. This means somebody should do an optimized minimum tooth iron stator profile, stamp it from exotic ultra-high flux capable cobalt (and possibly radially grain oriented) nickel and whatever else they did on the F1 KERS motor's lamination material, and do a hat-pin bus-bar slot "hat-pin" wound winding, maybe in pure silver wire. Space the windings hat-pin end-turns to have gaps like a hundred little folded copper bar heat-sinks, and some fins on the rotor that flow it though it and over them. I would think iron losses could be perhaps 1/4rd if you were only looking for a motor that saturates at a pretty low torque level compared to the guys who like to run 10,000w, but plenty for most <1kw kick-ass on a roadbike assist motors. Silent. Direct drive and durable and reliable and weather-proofed with exotic connections and titanium axles and beautiful forgings and ceramic bearings. Some day, and likely not too far off, Shamano (or some uber-premium component company) is going to make a "dura-ace" level direct drive assist hub. I would personally buy that for my roadbike, even if it cost ~$2500 or whatever. If it weighed just a pound or two, and gave like ~1kW asssit max, but when sustaining like 25mph 500w output it had perhaps ~>95% motor efficiency, maybe it's even >98% which would enable it being a thin-gap-ques design.

They used cobalt stators at an aerospace firm I worked with back in the day. They went into motors that powered most of the aerospace industry. Our largest capacity motor, which was maybe 20" long by about 12", was said to be able to power every single light in a city block. The burn in procedure on those motors was crazy. If memory serves me right, those motors ran at a couple thousand rpms during service, but the burn in test was ran at around 10,000 rpm for a couple of hours(in a blast proof containment housing, of course!). And in the 6 years I was there, I only recall a couple of them failing that test. Simply amazing what they can come up with when they need to.

 

[Chalo]

Some day, and likely not too far off, Shamano (or some uber-premium component company) is going to make a "dura-ace" level direct drive assist hub. I would personally buy that for my roadbike, even if it cost ~$2500 or whatever. If it weighed just a pound or two, and gave like ~1kW asssit max, but when sustaining like 25mph 500w output it had perhaps ~>95% motor efficiency, maybe it's even >98% which would enable it being a thin-gap-ques design.

Sounds like a job for a disk drive company rather than a cycle component company.

 

[liveforphysics]

Some day, and likely not too far off, Shamano (or some uber-premium component company) is going to make a "dura-ace" level direct drive assist hub. I would personally buy that for my roadbike, even if it cost ~$2500 or whatever. If it weighed just a pound or two, and gave like ~1kW asssit max, but when sustaining like 25mph 500w output it had perhaps ~>95% motor efficiency, maybe it's even >98% which would enable it being a thin-gap-ques design.

Sounds like a job for a disk drive company rather than a cycle component company.

Or a partnership between perhaps. Maybe launch-point to do the electro-magnetic design, then let Shamano handle the packaging into a bicycle hub, and leverage all the experience and suppliers they have for making uber high quality forgings and exotic materials experience/design and mass production know-how.

I don't care much how it comes in existing, but it will have at least 1 buyer when it's offered.

 

[Monsoon]

Some day, and likely not too far off, Shamano (or some uber-premium component company) is going to make a "dura-ace" level direct drive assist hub. I would personally buy that for my roadbike, even if it cost ~$2500 or whatever. If it weighed just a pound or two, and gave like ~1kW asssit max, but when sustaining like 25mph 500w output it had perhaps ~>95% motor efficiency, maybe it's even >98% which would enable it being a thin-gap-ques design.

Sounds like a job for a disk drive company rather than a cycle component company.

Or a partnership between perhaps. Maybe launch-point to do the electro-magnetic design, then let Shamano handle the packaging into a bicycle hub, and leverage all the experience and suppliers they have for making uber high quality forgings and exotic materials experience/design and mass production know-how.

I don't care much how it comes in existing, but it will have at least 1 buyer when it's offered.

and then couple that motor with a nanotube capacitor/battery for the lightest possible battery that will never ever die, no matter how many charges you throw at it. a battery that you can charge at 440v @ a couple hundred amps, in a matter of minutes, but run out at 48v all day long.
build a carbon frame bike, and with motor and battery be under 30lbs total.
and the best part of that scenario? they already have them in the laboratory. so it's just a matter of time before they work out all the angles, and we start seeing them in small electronics.
from that point, figure a few years for large enough capacity versions for our ebikes.
now we just have to convince shimano to do their fair share.

:lol:

 

[Bike_on]

Some day, and likely not too far off, Shamano (or some uber-premium component company) is going to make a "dura-ace" level direct drive assist hub. I would personally buy that for my roadbike, even if it cost ~$2500 or whatever. If it weighed just a pound or two, and gave like ~1kW asssit max, but when sustaining like 25mph 500w output it had perhaps ~>95% motor efficiency, maybe it's even >98% which would enable it being a thin-gap-ques design.

LFP,
I like the dure-ace hub idea. The Falco 500W hub is getting there. 1kw peak, 500W ave, 90% eft, 4.5kg, 9 lb, not 2 lb :? $900. Steel axel, not titanium....oh well. 5-phase direct drive hub.