Wheel building for hub motors.

Skyler

100 W
Joined
Apr 18, 2023
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136
Location
Alaska
I see a lot of hub motors, some geared and some direct drive on ebay for less than $100 up to about $160.

However I never see the spokes and rim under what other people ordered with the motor.

There should be spokes and rims from 20" up to 28" to build the wheels but I do not see any.

The front e bikeling motor on my Giant is making noise. I do not think it can be rebuilt like Bafang. Lots of repair parts for Bafang : Not ebikeling. I also have a 350 watt 36V Bafang that has a sensor issue. One or more is burned out. I had another Bafang that had a really bent rim so my friend swapped motors and sold the ebike.

I am looking to have him build me a wheel for the motor with the bad sensor and order a sensor less controller to run it. I could order the sensor array but a sensor less controller is only a few bucks more.

I was hoping to build a couple of ebikes with dual 350 to 500 watt motors and fully functional pedal gears and brakes. I could also include the battery in a rear rack. I could make a modest profit. I just need links to the spokes and rims or a place who can send me the wheel parts if I email the link to the motor ?????

My friend is good with brakes and I am learning. He can do disk if I build a 1,500 watt e bike. Since 26" is most common with kits building a wheel to fit a bike frame makes sense and hooking up brakes easier as everything lines up. 700c , 27.5" and 28" are getting more popular especially for taller folk.

Also dual 350 or 500 watt geared hub motors have a slight advantage over 1,000 watt direct drive in traction but around 5 mph slower than a single 1,000 watt direct drive. Geared hub motors offer superior torque so an advantage up hills. Also the direct drive is about 5 to 7 pounds heavier than two geared hub motors.

I know this as I have been running dual 26" 350 watt Bafangs for at least a couple years now and I weigh around 230 and excellent up small hills and very reliable. ebikeling geared 500 watt hub motors are not as good as 350 watt Bafang.

I hope someone will let me know. I would like to get started.

Skyler
 

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I've built up four 20" wheels with hubmotors from China. I used to buy 30mm Sun-Ringle rims on ebay for $25-30USD. I'd use Sapim Strong spokes which are 13G at the elbow and 14G at the ends to fit those rims. Those are close to $2 each with shipping from a local seller. So it's like $100 to build a wheel and I have to do it, but it's a far better wheel than what some chinese vendors ship for 20" rims.

For 20"-26" fat tire bikes, you can buy good Weinmann rims from Grin in Canada. I believe I paid $75USD shipped for 20x60mm, but that was 3 years ago.

You can buy all sorts of 26" rims from bicycle vendors or on ebay. Look for double wall, alloy of course. If you can live with 13G spokes. there are US sellers on ebay (childhood dreams is one) that will sell them for around $1/spoke. I've spoked several motors into 26" rims.

The hardest thing about building a wheel is ordering the right size spokes. Invariably, I get them wrong. Usually too long, and corrected with washers. One time I ordered spokes but forget to check the right box and got straight ones.

Doubt you will make any profit on a 26" wheel if you have to build it. The main reason I built my 20" wheels is because of the high shipping costs from China.
 
I hope someone will let me know. I would like to get started.
Has you friend laced many wheels? I've only built one, but had to do all the research before my attempt. It went OK, but I fixed any issue when retensioning it later and replacing a couple of spokes and nipples that I had mangled. Getting started is first determining the motors you'll use and a decent quality rim. It's best if you have both i hand before ordering spokes and nipples, since they can be very expensive and where making an error can double the cost of your wheel build.
At the same time, I'd get familiar with the Grin spoke calculator. There are several calculators, but Grin has some options that are specific to ebikes (like paired spoke holes, etc.). From the calculator, you will need to decide your lacing pattern (single cross, radial, etc.), and you will see you need several inputs, and those inputs are determined by carefully measuring the hub (flange width, diameter, dish offset), and the rim (ERD, offset). I only ordered spokes and nipples after taking those measurements several times on different days. Spokes are sold in 1mm increments so all of the measurements, entered into the calculator of your choice, will output the spoke lengths for the left and right side.

PS. How many miles are on the two motors with issues? Running excellent on hills vs. the failures may indicate things aren't as good as they seem, since things like hall sensors fail due to heat, which is the downside of geared motors (no ability to shed heat). If you're putting in new motors, it might be a good investment to open them up and adding temp sensors so you know whether or not you're cooking the motors.
 
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There should be spokes and rims from 20" up to 28" to build the wheels but I do not see any.

It doesn’t quite work like this. The size of the spokes are determined by measurements. You would need to take measurements of both the rim and hub motor then plug those numbers into an online calculator to determine the spoke length.


Someone correct me if I’m wrong, but trying to run that motor Sensorless is not going to give you a smooth running motor. Would be better to replace the hall sensors and do it right. Especially if you or your buddy is going to take the time to build that motor into a new rim just change the sensor out.
 
There should be spokes and rims from 20" up to 28" to build the wheels but I do not see any.

There are. Trust me when I say you don't want rims and spokes offered for sale by the hub motor seller. They're garbage 19 times out of 20. Go online if you know what you're doing, or to a bike shop if you don't, and get sturdy well-made rims and quality double butted thin spokes to fit your motor. Cross-one lacing for 26" inch or larger wheels, radial lacing for 20", one or the other for 24" depending on how big the hub is.

The claimed wattage of the motor is almost irrelevant because there's no standardization in how to determine it. Better is to multiply battery voltage by controller input amps, then divide by 2. That way you're not only close to the real world motor output, but you can compare apples to apples.
 
Thanks for the info.

A 17 amp controller with a single 350 to 500 watt geared hub is not enough for steep hills but dual 17 amp controllers and geared hub motors do well up small to moderate hills.

My Giant Roam has a 26" Bafang in the rear with a cassette and 700c e bikeling geared hub rated at 500 watts but both controllers are 17 amps. The front hub is making a lot of noise and as far as I know no rebuild kit is available for ebikeling. I run 13S LFP 43V and the motors can both do 36/48 but see the 500W rated e bikeling 1s not as durable as 350W Bafang. The 8fun 8 pin motors.

My solution is to remove both motors. The rear Bafang still works ok but have to tighten the spokes as will come loose. I decided to take the rear and pair it up with a front 26" Bafang. Both on a 26" beach cruiser. It is a good friend who is about 260 pounds so he will need both motors. He will need to get three SLAs for now until I get my spot welder next month and start building Lico and LFP packs. He owns the beach cruiser and I have another friend who can hook up front and rear brakes.

I will include a spoke wrench and will show him how to check and tighten. I only live a few blocks away so can check it routinely to keep it maintained. My other friend can do pedal chain and brakes. I am not as good as him yet.

I am only charging him $200 with installation. A brand new 350 watt Bafang motor is > $200 and the kit > $300. Two installed is a great deal for him who wont be riding more than once or twice a week about 5 miles. The brakes and battery mounting will be done by my other friend but probably only be $20 or $30. I will talk to him.

It says free shipping so I will only need $20 and change then to order the 1,500 watt kit. I see it sports a 35 amp controller. The kit I got for my full suspension was $206 I think and free shipping. I think it was $222 with tax so only $3 more for this.

The other only has a 30 amp controller and rated for 35 mph. I got it to 54 kilometers per hour which is about 33.5 mph but not sure if was completely flat. Also I changed the tires to more knobby ones. Also I am about 225 to 227 pounds and my batteries around 30 pounds.

The kit below looks to be a REAL 1,500 watt kit with 35 amps and 37 mph rating.

I will be ordering it for the back of the Giant. I wont be adding a front motor as I put a 1,000 watt Unite brush motor in the front of the full suspension and the front shocks fully function. I have not tested it yet but the bracket is bolted to the top of the fork and is stationary. I used a modified chain tensioner so am hoping for the best. Total power > 2,500W. the chain is geared for about 33 mph.

Dual motors and full suspension is ideal for grass and off road terrain. The Giant only smooth pavement for longer trips. I would love to build a 17S 10P LFP pack with 26650 A123 cells. Maybe 18S but maybe not if 60V caps.

No pictures until I get a memory card and battery for my old mini camera. Cell phone and tablet got stolen.

Skyler.
 

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I had a chance and I bought three rims 26 in at about 25usd for rim brakes or disc.And three sets of spokes from grin 13/14 Spain for about 125usd DD rear wheel builds.
I got an Alibaba almost mxus kit it's a Sali 48v/72v 60amp kit for 345usd shipped. Everything but a two tire and battery.. a Mxus kit would be $600 shipped a bare motor 390usd shipped.
I got the Sali get in and the controller has a good start and not so jerky and it takes time to get up to the 60 amps but it goes 46 miles an hour 26 in rim disc brake only. I started a thread on the Sali motor. As I take it out again because somehow a dnp 7-speed would not work with my frame or maybe the motor won't accept a dnp 7-speed with 11t with a lot of washers inside of it to make it fit to my Giant mountain bike frame. Still confused why it locked up. But that's what you get when you gamble Chinese. As they say don't worry don't worry.
What a brush motor in the front you are a caveman.
 
After wading thru a lot of subjects here in your posts in this thread am I correct in perceiving you are wanting guidance on lacing rims to hubmotors?

If so, watch three excellent Grin videos, geared towards wheelbuilding hub motors (important different details from wheelbuilding standard hubs):

On this page:

 
I strongly suggest you buy 2 sets of spokes and nipples or at least 10x spares minimum, Nipples will get dropped.. a blob of blutac on a screwdriver tip or a small tear of gaffer tape to hold the nipple as you insert it into its recess helps if you dont have the 'special' tool

Im doing a wheel atm so far im on my 3rd set of spokes (2 x wrong size) Ive threaded 2 spokes and nipples and lost 1 nipple, My rim has a deep nipple recess and extraction of a dropped nipple involves shaking for what feels like minutes.. so am waiting for a 4th set to arrive so the two threaded spokes which will never tighten correctly and the lost nipple can be replaced..

As for the job, start at the valve hole and let the bias of the spoke holes (to the left or right rim side) dictate which side you lace the spokes from the hub. left bias left side of the hub spoke fill it etc.. a simple single cross over between adjacent spokes is an easy pattern to keep track of, and a cylinder to balance the hub on at eye level is a must. a couple of rim supports help too to start with.

Fwiw i must have covered 30 miles visiting all the places i would have bought spokes last time such things were on my mind and those still in business (less than half) no longer stocked them.. ebay-china was the only option left beyond a special order and professional motor sport prices..
 
Chain Reaction Cycle has brand name (not generic) spokes but not much lower then 180mm, they have an easy way to find out all the sizes they have at a glance. On the left hand side the filter shows all the sizes.

I buy my controllers from evfitting greentime on Aliexpress, but they sell different custom sizes in generic spokes. Try to order Epacket when choosing shipping option for small orders, comes quicker and cheaper to North America.

Grintech has quality spokes to order in Vancouver Canada.

Ebay is full of generic spokes and generic rims if its apart of a wheelset or individual, generics are only good for cruising around slow in the neighborhood riding ramps to sidewalks, if not and you want to pop curbs, or anything else that is stressful on spokes then they will last as long as you take care of them, keep them tight, replace broken spokes immediately without delay and maybe, just maybe your generic rim wont crack. Build up a nice motor with generic shit, no thanks.
 
Cheers @caleb unfortunately im looking for 174-175mm 12g spokes, so chain reaction isnt an option right now although i could swallow their prices, i certainly missed them in my initial browse..
And grintech, well after shipping and vat and vat handeling charges it would almost be cheaper to buy a new wheel and hub motor complete from china $1.50 per spoke! soo assuming a reasonable shipping charge ?$30? so will be well in excess of $100 by the time agent and handling fees for vat charges are levied by ups.

Yeah pop curbs? i do that with my vape pen in hand while posting selfies to instagram, IM a grown man ffs.. If i wanted to pull stunts i would mount a real bike not a pedelec.. crusing slow sounds mighty fine and is sure to get my baked goods home uncrushed too.
 
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Cheers @caleb unfortunately im looking for 174-175mm 12g spokes,

You might think you're looking for 12ga spokes, but you're doing yourself a grave disservice if you use spokes that thick with an ordinary bicycle rim. You'll get lower load capacity, much higher maintenance, and lower rim lifespan than if you used 14ga (or better yet 14-15ga butted) spokes.
 
You might think you're looking for 12ga spokes, but you're doing yourself a grave disservice if you use spokes that thick with an ordinary bicycle rim. You'll get lower load capacity, much higher maintenance, and lower rim lifespan than if you used 14ga (or better yet 14-15ga butted) spokes.

anything smaller than 12g simply falls through the hub holes. im replacing like for like in a collision damaged wheel.

Lower Load capacity? grams, milligrams? picograms? how? due to less elasticity in the wheel structure? cant see it myself?

Much higher maintenance? just what spoke maintenance is possible 3 months down the rd when atmospheric moisture and galvanic corrosion will have welded the spoke and nipple into 1?

Only thing ive ever known to kill a spoked wheel is a collision, and blaming spokes post collision for damage sounds a bit like scape goating..
 
anything smaller than 12g simply falls through the hub holes. im replacing like for like in a collision damaged wheel.

Use 2mm stainless steel washers on the spoke heads, 4mm washers or nipple washers at the rim if necessary.

Lower Load capacity? grams, milligrams? picograms? how? due to less elasticity in the wheel structure? cant see it myself?

Thin spokes can elastically retract enough when tight to allow the rim to flex under bike and rider weight, bumps and other dynamic loads, without the spokes going slack or having to be tightened too much for the rim to withstand.

Much higher maintenance? just what spoke maintenance is possible 3 months down the rd when atmospheric moisture and galvanic corrosion will have welded the spoke and nipple into 1?

Spoke threads must be lubricated. If you do that, they won't become stuck, and you can true the wheel as needed. If you use too-thick spokes, they will slacken frequently under load, and the nipples will unscrew gradually at first, then quickly. If you stick the nipps in place with corrosion or threadlocker, later service will become difficult and complicated.

Also if you use too-thick spokes, your rim is much more likely to pucker or crack at the holes because of fretting or overload.

if you use motorcycle spokes, you must use a motorcycle rim to allow sufficient spoke tension to avoid problems.

The fact that bicycle hub motors come with too-thick spokes as original equipment is a matter of manufacturers giving people who don't understand what they're doing, what they ask for. It also allows manufacturers to use cheaper, lower quality spokes without incurring immediate failures. But over time they will fail anyway.
 
You can curve the washers with a tool that flares the end of the pipe.
I do normal flat washers for the hub flange, but if the washers are to big they will interfere with the cover plate.

Motorcycle and moped rims have the bowl where the nipple sits.
 
Use 2mm stainless steel washers on the spoke heads, 4mm washers or nipple washers at the rim if necessary.



Thin spokes can elastically retract enough when tight to allow the rim to flex under bike and rider weight, bumps and other dynamic loads, without the spokes going slack or having to be tightened too much for the rim to withstand.



Spoke threads must be lubricated. If you do that, they won't become stuck, and you can true the wheel as needed. If you use too-thick spokes, they will slacken frequently under load, and the nipples will unscrew gradually at first, then quickly. If you stick the nipps in place with corrosion or threadlocker, later service will become difficult and complicated.

Also if you use too-thick spokes, your rim is much more likely to pucker or crack at the holes because of fretting or overload.

if you use motorcycle spokes, you must use a motorcycle rim to allow sufficient spoke tension to avoid problems.

The fact that bicycle hub motors come with too-thick spokes as original equipment is a matter of manufacturers giving people who don't understand what they're doing, what they ask for. It also allows manufacturers to use cheaper, lower quality spokes without incurring immediate failures. But over time they will fail anyway.

OK you have a like before i even read this so 2 to 1 so far and counting.. sorry 3:1

Not totally convinced its gonna make any perceptible difference but since i have been wrong before and will no doubt be wrong again I'm listening/considering..

well 2mm and 4mm SS washers thats a local pick up and pennies.. (yes i already drilled out the rim holes to 5mm for the larger nipples hrmph!)

Sticking to bog standard cheap amazon delivered 14g spokes, I could let the delivery race decide which gets attempted first.. the 2mm spokes will take about 10 days to arrive, so i have a few days to ponder.. after all whats 1 more set of spokes its only another tenner..

So, IF I concede and follow the collective wisdom (access to which is why i joined up) .. when fitting a 14g spoke with a 2mm ss washer through the hub, should I lightly hammer/punch the spoke end into the hub depression to cup the SS washer?
Ahh you answered that while i was pondering @calab

Hmm amazon want £15 for next day delivery.. I thought the lacing of the wheel would be the tricky part, as it turns out thats easy if a little frustrating.. its getting the right size bloody spokes thats the issue..

sod it..
 
It takes patience, you have to be in a certain mood, more like a Zen state when lacing a rim to a hub motor.
One thing is known for a fact, it cant be rushed. Miss one crucial step and you'll never forget putting that one spoke over instead of under.
You dont need no fancy gadget either, you can use your own bicycle to true the wheel.
Some hubs come with the large spoke holes on the flange, which is why washers may be needed.
You can redrill the flange to the same hole count, like 36 to 36, but converting either way may put a couple holes to close together for integrity of the flange itself. Might be wise to consider 32h rims, instead of redrill 36h flange to 32h flange. Just saying A simple device from kindergarten math class can solve where the new holes go, mapper use same thing, boaters to, naval captains..... sea-persons.

Geometric Tool – Compass​

 

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when fitting a 14g spoke with a 2mm ss washer through the hub, should I lightly hammer/punch the spoke end into the hub depression to cup the SS washer?

In my experience, just putting adequate tension on the spoke will conform the washer to the hub hole and the spoke head.

Getting 14ga spokes custom cut is pretty easy and common. Other gauges not so much. There's someone in Old Blighty who does it cheaply online.


But he's not the only one. Just look around.
 
A spoked wheel is an amazing engineering feat when you think about it. Requires a certain amount of elastic tension. Spokes that are too thick cannot be tensioned enough before the rim will crack. Best practice to avoid damage: Use bicycle spokes on bicycle rims, motorcycle spokes with motorcycle rims, automobile spokes on automobile rims (rare nowadays).

The others have given you solid advice: Use your 14ga spokes with washers at the hub flange, lube the spoke threads and nipples.

There are numerous reading materials out there if you need to understand the dynamics of the spoked wheel.
 
Ok things have not quite gone to plan, I ordered some 174mm 14g spokes, as my 170mm 12g spokes fitted a rim with a 4mm deeper wheel rim than its replacement.

However there is only a 2-3mm difference between the 170mm spokes and the 174mm spokes??

In the pics below i have lined the spokes together such that the Jhooks are lined up, they are not likned up with the zero point on the scale..

No package note or delivery slip or invoice and nothing on the box indicating size.. unless its the Chinese characters?

So i think ive been sent 172mm spokes in error? or have i.. hanging the spokes off the ruler which is zero indexed at its edge indicates the spokes are 173mm..

either way i cant place more than the first 11 spokes in the top plane of the wheel before being unable to add more..

Oh and lots of fun n games before getting here, i had to drill out the outer rim holes to accommodate the 4mm washers, and then i spent 2 x attempts forgetting to skip a hole DOH!!

SO.... what size should i order next? 175 176? or should i send them back for being 173mm not 174?

one thing i dont think is relevant but if omitted will turn out to be crucial, originally all spokes were threaded from the hub outside in, i elected to alternate this as per usual with wheels I dont think that would have any impact on spoke length required however..

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Spokes are formed at the elbows once installed and brought up to tension. Brand new spokes typically measure 1mm shorter than their labeled size.

Usually you need to add a little length to compensate for the length taken up by the washers (when you use washers). But having spokes 2mm longer or shorter than ideal is rarely any kind of problem. If you're worried about it, you can use longer nipples which usually have a slightly longer threaded section.
 
Typical, ive just pulled the spokes out of the wheel and packed them up, Forgive me for using incorrect nomenclature but let me describe the best i can.

The '174'mm spokes would not sit all the way in the rim when over half the top layer (2 layers or hub sides) of spokes were inserted some in the centre of those fitted protruded a cm beyond the rim while others were taught and this time round they were laced alternatively I taped over every alternate rim hole so i only used ones designated to the top layer. So while longer nipples may let me mount the 12th of the top 18 spokes ok, spokes opposing those standing proud of the rim will need significantly more nipple length than 1 or 2mm to meet and the result will not good as those standing proud spokes will remain so?

edit* and yes i had slackened off every nipple under tension until just biting,

I can probably rebuild to this stage again tomorrow in a short while but not tonight....... if my poorly worded description is inadequate.

I still have however some 2mm 175mm long spokes in the post which without the need to thread both spokes and nipples through washers will take less time to fit for size (not use) and have more chance of success in my current estimation.

I had btw been round every nipple ensuring it was not caught on the lip of its washer and that each washer was through the outer rim too..

Please correct my logic here, the rim that mounted ok with 170mm 2mm spokes easily is 4mm deeper that the replacement without pulled through spoke holes resulting in an 8mm larger inside diameter of the new wheel/rim. spokes are radial, so 1/2 the 8mm back to the original 4mm rim width difference.. so 174mm spokes should be OK??

the original rim with its deeper spoke recess was a PITA to push the nipples cleanly through and nipples were easily dropped within the rim but all the spokes lined up and threaded ok bar 1 i was careless with which i shortened to remove the bad thread and it still mounted ok..

Tomorrow evening i will also try to form a m4 washer to the inner rim surface with gentle persuasion but a visual inspection didnt indicate this was necessary.

Thanks for the support btw hope the op doesn't mind the thread hijack too,,
 
Thanks for the support btw hope the op doesn't mind the thread hijack too,,
OP hasn't been seen in this thread for over six weeks.

If you haven't already, watch these three videos at the bottom of this link (From post #8 above). Will give you more confidence in your wheelbuiding project:

 
OP hasn't been seen in this thread for over six weeks.

If you haven't already, watch these three videos at the bottom of this link (From post #8 above). Will give you more confidence in your wheelbuiding project:

Cheers, will do.. Ironically after cutting out one of the few straight spokes from the original wheel and guesstimating its pre-cut length I laced that what turned out to be a very damaged rim easily, only when i start measuring properly for the replacement do i get issues..
perhaps it was the half dozen ripped out holes in the damaged rim that enabled its rebuilding so easily..

I have to believe that my initial guess was close but low and i benefited from the 1-2mm leway @Chalo mentions and subsiquent conservative measurements have compounded that error into the realm of unworkable..

I have some longer 175mm 12g spokes en-route still, which i will fit for sizing purposes, if they fit or are a closer fit? i can judge what size 14g to order subsequently..

This bike was given to me as a 'keep the old sod busy project' and its sure a success on that front..
 
Nipples will get dropped.. a blob of blutac on a screwdriver tip or a small tear of gaffer tape to hold the nipple as you insert it into its recess helps if you dont have the 'special' tool

Im doing a wheel atm so far im on my 3rd set of spokes (2 x wrong size) Ive threaded 2 spokes and nipples and lost 1 nipple, My rim has a deep nipple recess and extraction of a dropped nipple involves shaking for what feels like minutes..

...after cutting out one of the few straight spokes from the original wheel and...

Here you go: you can grind or file down the end of that cut spoke into more of a point and use that as a tool to more precisely insert the nipple into the deep recess to get the threads started without dropping it. IIRC this is demonstrated in one of the videos I linked to several times above.

This bike was given to me as a 'keep the old sod busy project' and its sure a success on that front..
Made me LOL,:ROFLMAO: LOL
 
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