Potential DIY solution for spoke & spoke related damage?

[AdamB]

I've been thinking about wheelbuilding a lot & I'ld like to run a few things by you guys...

Premise- MPs/SPs have issues with spoke & spoke related damage from the angle of the elbow/nipple leaving the hub/rim & gaps between parts causing tears from uneven forces on tiny areas & fatigue from chronic movements.

DIY Solution- Make a custom "washer" to match individual space between the 2 parts. Best guess, lightly lube parts & then fill with epoxy after wheel is balanced/true. An epoxy with a longer set time can be put between the nipple & rim prior to tightening as it may be hard to put in after.

I'm not saying glue it together, just fill space between so forces are evenly transmitted between the parts & won't move.

MFG Solution- (A) Tighten QC & tolerances to make a universal washer to do same; or (B) Include epoxy with instructions to make washers as above.

I've done all sorts of stuff like this. For ex. my oven door handle broke where screws attach to it. I filled the hole with epoxy, rebuilt with lubed screws & let it cure. After I was able to unscrew it & rebuild it.

We unscrew it every month to disassemble the door to clean inside (mother has OCD). It fits perfectly & is still intact despite dozens of unscrewing & 1,000s of opening, closing, leaning, etc!

i do similar things when prototyping matching parts for stuff & had no issue with it. Epoxy may not be the best for this but the principle may apply.

Ideally they'ld just fix the flawed angle/shape of spoke/nipple but that isn't the way it is on existing products. That may not be possible given the size of our motors/ rims/ spokes/ nipples. At least until they do, we at least have an after market solution that's cheap & simple.

It may even allow for other lacing beside radial & 0 cross. The other nice part is it's universal instead of trying to fit each type/size/shape spoke/nipple/elbow/rim/motor, etc.

So what do you think? It's just an idea,  maybe a bad 1, but it may fix it. Combine. with a bit of thread lock & it should be a far more durable & strong wheel.

[Morgen 3Eman]

Hi Adam,

Alan is the rim/spoke genius you should listen to, but your idea seems reasonable to me.  I  would suggest using a filled epoxy, such as JB Weld, as the inclusions makes it stronger than a plain epoxy puddle.

Have you thought out how/when to put the epoxy into the assembly of the wheel?  I suspect that will be a troublesome event:)

Let us know how you do with this idea.

TTFN,
Dennis

[OCD]

Why not mark the direction of the spokes on the assembled wheel, disassemble it, then angle drill the spoke holes to reduce the bend angle of the spoke where it meets the nipple. I just finished an e-wheelset with 24" x 2.5" rims using 13 ga spokes on the rear which needed to be drilled for the larger nipples anyway. Not perfect but a much better angle than the stock wheel. Also you can use 13/14 ga butted spokes which are more flexible and less likely to snap off at the threaded end.

(the other) Alan

[AdamB]

Heya all...

Dennis we think alike... JB weld is what I usually use for this type of thing & most epoxy work period. Though I've been using Marine JB Weld lately (not waterweld) & I'm liking it so far.

Btw- here's a trick for working with all 2 part epoxy... Use a cheap exacto snap off blades & knife. It's thin enough to act like the perfect putty knife, cheap enough you can toss after user, flat edge works while for preventing a thin layer of unmixed epoxy & works well to force the epoxy into various parts...

Tip 2- ALWAYS WEAR GLOVES!
Tip 3- if you want to have a smooth surface/easy presentation, spit a tiny bit on gloves finger & use to smooth out surface.
Tip4- If you need it runny, use immediately when mixed: thicker then wait a few minutes until its thickness sufficiently. Don't wait more then 20 minutes or so after mixing or you'll have issues.

Yeah, I have thought about it & I think it depends on how fast the wheel can be trued/balanced & the individual parts. I'll have the chance with my coming wheels to evaluate those things. I suspect different ends may need different timing.

I'm beginning to think if your named Alan, you are predestined to be an ebike mechanic. So many Alans:). But I do really appreciate their help!

As for your statements Alan... I agree min single butted spokes are absolutely essential in my opinion.

That said I am concerned about redrilling the hole. I think it may leave an incomplete circle that worsens then base metal tearing issue. The holes best difference is a perfectly symmetrical circle & worst enemy is a small imperfection.

I would think a 13g/14g butted spoke would need a redrill just to fit (without considering directionality).

Also what do you think of velocity Veloplugs instead of or in addition to rim tape?

Adam

[Bikemad]

Why not mark the direction of the spokes on the assembled wheel, disassemble it, then angle drill the spoke holes to reduce the bend angle of the spoke where it meets the nipple.

Unfortunately, it's not quite that simple. If you had a drill shaped the same as the nipple outline it might work, but I suspect you would drill right through the rim on one side of the hole making it very weak and likely to allow the nipple to pull through.

When the spoke is loose it will often allow the nipple to align correctly, but as it is tensioned, the nipple is pulled towards a natural seated position inside the rim, which causes the spoke to become badly bent and strained at the nipple end.

I have already tried to explain why this happens using a simple diagram:



But now I can clearly demonstrate what actually happens in real life.
The hole in the rim is already large enough to allow the spoke nipple to exit at the required angle (albeit excessive), but just look how much its angle changes as the spoke is subjected to tension:



The only reason for the excessive spoke/rim angle is to accommodate the larger hub, but this causes the spoke to exceed its working angle:



The problem can simply be alleviated by mounting the spokes at a more acceptable (more conventional) angle by offsetting the holes in the flanges as implemented on the revised Magic Pies:



As the resultant 9° spoke angle is far greater than a conventionally spoked wheel, it will place less load on the rim when the wheel is under torsional load and will have no problem whatsoever in transmitting the maximum torque from the hub to the rim (unlike radially spoked wheels which typically place tremendous loads on the rim).



In my opinion, the excessive angle caused by the crossed spokes on the above Magic Pie is simply unacceptable, It would not be a problem if you were lacing the hub into a motorcycle type rim that was specifically designed to allow the spokes to exit at a large angle:



Many people are under the false impression that the increased angle is required to cope with the huge torque of the hubmotor.
But let's consider the front wheel shown in the above picture which, as you can clearly see, does not have excessively angled heavy duty spokes, yet under heavy braking on a conventional eBike, it will have to withstand a lot more torque being transmitted through the relatively tiny flanges on the standard disc brake hub than the Magic Pie is even capable of producing!

Check out this post for more information regarding preventing broken spokes.

Alan
 

[OCD]

The angle on the nipples in my 24" builds are no different (possibly less) than the angle of a stock, normal GM wheel. If mine is unacceptable, then all GM products are unacceptable (which I already believe). The spoke angle at the nipple on GM factory builds is so extreme that you often cannot reuse the nipples/spokes when you disassemble a wheel. I routinely run 3000 watts at 80 amps through this setup, never had a broken spoke in 6 years. I also build them with motorcycle rims which look nice but are considerably heavier. For single butted spokes you should not need to redrill the rim holes to a larger size, just angle drill them, it's not as good a the dimpled motorcycle rim but better than the cheap GM factory build. If you go up to 13ga (which the rear in the pic has) you will definitely need to drill larger holes for the nipples (don't use the thin walled conversion nipples like Grin.ca sell, they don't even recommend them). Also, a 26" wheel would not have as extreme an angle, these are only 1 cross lacing.

Ps: if you JB weld your spoke nipples, you will never be able to re-tension them= bad idea

an Alan by any other name will still have opinions...

[AdamB]

Explicitly- don't JB weld anything to anything involving parts that need to be able to move freely! Nor will I be responsible for anyone who refuses to listen to that advice!

Specifically, I said lube all surfaces that may come in contact with the JB so that they would NOT BOND TOGETHER! Obviously, if you bond the spokes &/or nipple &/or rim &/or washers to each other you will have bigger problems then fatigue or tears!

I solely suggested using an epoxy (like JB weld) to create a custom washer that allows each part to be completely supported by a matched surface! Naturally, if you don't adequately lube the surfaces, they will bond & you'll be left to try to separate parts that shouldn't of been bonded together in the 1st place!

*(Btw if you didn't listen to that advice & now have your nipples bonded to your spokes, google JB weld & high temps/mechanical removal, have fun, it's a long & unpleasant process but make sure this time you actually follow the instructions)*

However if properly lubed, they will NOT bond to each other (that's why the instructions say to properly degrease area to be bonded) then you'll be left with parts that can be undone & a newly formed custom shaped washer that perfectly matches the space between the parts!

Seriously, what am I missing? I've said all this several times!

Adam

[Bikemad]

Also, a 26" wheel would not have as extreme an angle, these are only 1 cross lacing.

The modified Magic Pie with a standard GM 26" rim has a 9° spoke angle but by crossing the spokes you would increase the spoke angle to 18°:



The modified Magic Pie with a standard GM 24" rim has a spoke angle of 11° which would increase to 22° by crossing the spokes.

The original unmodified Magic Pies had a 25° spoke angle with a 26" rim (and a 30° spoke angle with a 24" rim) and this angle was far too excessive:



This was why I initially proposed the unorthodox spoke pattern:

Golden Motor will take your suggestions and modify the motor ring to off-center like your modifications. Basically we will use thicker motor ring (30mm instead of current 23mm) and machine it to become off-centered.

Philip, thanks for the positive response.

I basically carried out this modification in order to satisfy my own needs, but it's very encouraging to know that others will benefit from my efforts.
As you are proposing to change the motor ring, I would like to put forward some further suggestions which you may want to consider.
(These were noticed during the rebuilding of my wheel) :

• The spoke holes must be repositioned to reduce the excessive angle of the spokes, I would suggest they be staggered in pairs rather than evenly spaced, and shorter spokes could then be fitted without crossing over each other. This should give enough angle on the spokes to safely transmit the torque (much stronger than radial spoking) and would more importantly, allow the spoke nipples to seat correctly with the current rims. (It would also make the wheels much easier to build)
  This should eliminate the existing curved spokes and badly aligned nipples completely making a much stronger and nicer looking wheel.
  I will try and post a diagram showing my suggested spoke hole arrangement when I get chance.
  
  
• The current spoke holes are too large, the flange is too thin and the countersinking is too deep for the spokes being used, (see this post for more details) and I had to use two 0.6mm thick washers under the heads of each of the spokes to get them to sit nice and snug against the flanges (with both the original and my modified flange).
  I suggest the flange is sized and machined to correctly accommodate the spokes.
  
  
• Thinner gauge spokes could be used and should be just as strong, more flexible and able to absorb more road shock than a thicker gauge spoke using with the same size thread.
  
  
• Wheels need to be built with the rim perfectly centred on the axle fixings, and the rim should also be concentric with the axle to reduce vibration at speed!

Whilst your 22° spoke angle may be marginally better than the original 26" spoked Magic Pie, I think 11° would have been a lot better (without the crossed spokes). 

Alan
 

[AdamB]

Since many doubt this is possible... I unscrewed our oven door handle & took pictures to post. Hopefully you'll be able to see it works.

They are not the best but zoom in & look carefully, you'll see the threads in the JB weld patch & the lubed screw beside it- wholly unbonded!

It's a great example, the screws/ surroundings were lubed & didn't bond! The socket it screwed into wasn't lubed, so it bonded! It's since been undone & redone countless times without any issues! Still, as a rule I say don't play with it, if not needed!

Prior the threads were destroyed & it was impossible to open the door with the handle! So we had to grab the door on both sides using oven mitts & got burnt often.

So I JB welded it... I figured worst case, it all glued together & couldn't be undone or didn't bond at all... Either way, no worse off!

So, when I knew the oven wasn't needed, I grabbed the supplies & just did it. Since, it's worked properly & been undone countess times to clean without issues!

Of course, this doesn't mean it can be done with spokes, nipples, washers, rims, etc! However it does prove the principle of using it to make matched parts without bonding it all together!

I've included (or tried to) 2 pics of the job but if you have difficulty seeing the images, let me know & I'll try to fix it if I can!

Adam

[AdamB]

The stupid forum kept complaining so I had to make this 2 posts for it to be happy (or at least happy enough, it still kept randomly claiming I'ld posted it already but I checked & nothing, as far as I know it only allowed me to proceed just now with 1 picture...

So anyways here the 2nd picture...

[GM Canada]

Not sure if this is on topic or not, but I did just happen to finish making a video on building a Magic Pie wheel for those that have never tried it. Its actually still uploading while I write this so I hope the link does work when it comes live.

Gary

https://youtu.be/xBseRk30xMs

[AdamB]

By saying "build a Magic Pie wheel"  do you mean like taking a hub, rim, spokes, tires, etc. & building a wheel... Or do you mean, taking a pre-built wheel & putting it in a bike to convert the bike to an ebike? Or rebuilding the guts of a pie? Or something all together different?

When you say "Magic Pie" which version? Oh & I've been meaning to ask, I keep seeing people refer to early Magic Pies as "mk" what's that stands for? I thought they were always called "MP" or "Magic Pie" not "magic K-something"...

I'll try to check out the video when I have some extra time.... Though I guess even if it's off topic, these are GM's boards, so you can do whatever you please!

Incidentally- now that you are here, what do you think of the idea of a custom shaped washer between the spoke & rim/hub (obviously not gluing anything together & whether epoxy or something else is used)...

To ensure that all parts have a perfectly matched surface to support them & evenly transmit their forces to the surrounding metal (not just all on a tiny %) & the parts can not move/bend all the time (instead of constant, repetitive small motions that cause metal fatigue)?

It won't make the actual angles any less then they would otherwise be in real life but it may make the components better able to withstand the extreme angles they are subjected to &/or increase the safety margins of what the components can safely withstand...

Adam

[GM Canada]

By saying "build a Magic Pie wheel"  do you mean "

Watch the video...

Gary

[Supchrgamx]

since we are on wheel discussion I feel I have to give my 5 cents
for me its allways been sideway deflection , if you put the wheel on the ground and slide a long pipe on the axle and pull sideways you get more deflection with straight spokes then crossed spokes. crossed spokes do hit the rim at more of an angle ,so I lay out the spoke angle on the rim the way the spokes hit it and extend the holes in that direction only so the spokes stay straight and do not bend. never had a spoke pull through. personally I would like the spokes wider across the motor to give a more wider angle to the spokes and a wider rim, cant count how many times I snake bit the inner tube on their rim. much safer running on a wider tire anyways. made that change after sending my self to the hospital. and if you were to get really creative, one option would be to increase the spoke count, but then you lose the option of different rims,option 2, if they increased the width of spoke why not stagger the holes so all spokes can come out the outside of the rim and have them just touch as they cross each other. that would also help in the deflection. just my view

Laurence

[AdamB]

To be clear, Lawrence...

I'm NOT a fan of radial spoke patterns! Esp. if the only type used. In some limited cases radial (hybrid or alone) has its place when beyond normal/ ideal... It's just people like to be special, different, etc... Even when they don't get the why or is bad idea.

For ex. I'm in a wheelchair (WC- or like), have a service dog (SD- normally but no pup ATM) & a wacked brain that means, among others, I'm an idiot savant 24/7/365... I am not ashamed & I don't want to demean others...

But... it's not cool, fun, preferable, etc. to be damn near perfect in a few things & a total moron in the rest...

It's not great, the easy life, relaxing, etc. to be in a chair or like 24/7/365...

It's not simple, perfect, or even 100% fun to HAVE TO ALWAYS have a dog around (even if as great as mine) & plan your existence around a dog! Or fools waving their hands in your face while dancing around testing if you can see... (surprise, I see an idiot; but yes, I need my SD & I'm not a fraud!)!!

No joke, since I got a SD, I don't get menus in restaurants & if I insist, I get stuff like, we don't have braille menus sir... Or go to a movie & the ticket guy argues he can't cause blind people can't see movies... Then passersby have a fight with the guy that blind don't watch movies, they listen to them & I miss the movie...  They're both wrong, blind people watch movies too & a person's disabilities doesn't change the guys job description "sell ticket to who pays for it"!

I'm off on a tangent but I have a point... Too often we only see how we see it & forget there's reality outside of us & it doesn't matter what we think, feel, believe or even if we like it. Sure, lots is just about opinion, feelings, perspective, etc. But there's almost always a right & wrong way (more a select few right & infinite wrong ways) even if it's not known...

For ex, if I built my new powerchair chair by wiring - to + & + to -... It won't matter if I want, need, pray, beg, or believe it works... It's won't work!

It won't matter if I followed the instruction/ "rules" to a "T"... It won't matter if all says it's right... It won't work & I'll stay house-bound, dragging myself on the ground in agony!

That's reality, take it or leave it but I have no time for games &/or denial... I'm dying & every second I waste, is gone forever & is a second I could do something useful with it & another thing that's important to me that I will miss out on...

So many are so focused on trying to justify that what they did as right/best or must be. As if we admit we weren't correct but managed to get by or not ideal but sufficient for our us, that it will invalidate their accomplishments... But if doesn't... The win still counts & info gained is still important!

Sadly, the wriggle room that many have rarely applies for me... I push things to their limits & too often break stuff because the safety margins built in for others, disappears for me!

I'm glad for those who find that "x" phone (or wherever) was durable enough for them but it does not mean it'll survive for me...

No joke, I was once sent home from my job in a call center as all the phones I used, died moments later. I did nothing wrong, just being me & that day dozens of phones went on strike to avoid working with me;) ok, no joke but is funny!;)

I can't explain it, & neither could the tech guys or anyone else. It just happened & after hours of broken phone systems, my boss gave up & sent me home... The next days, all worked fine & we never knew why but I worked there for a while after on the same systems without issue.

As I've often said, I've no pride & will easily admit if wrong or don't know... it's why I'm here... I've never built an e-bike or like (gas powered roller blades & go kart type stuff being the exception) & I know enough to know that I need help.

I'm a social moron & often find my foot in my mouth or misunderstand things: even when I mean no harm/ill will & yet I still manage to offend...

My only hope is to be clear enough & avoid screwing up long enough that I can achieve my purpose here... I.e. to succeed building my new powerchair that'll meets my needs within my limited resources & abilities (if, it also help others, all the better)...

The reason I'm so worried about the wheel's integrity (among other things), is I know I'm not in majority that'll easily remain within the safety margins... If I screw up, I can't just start over or buy a new whatever I break or take years to learn things for myself!

Every gain & improvement I can find, will mean I'm that much less likely to fail, lose it all & become the homeless guy always on the same corner, who dies, frozen into the wheelchair he stole from the hospital while countless pass, never noticing he'd died.

Don't tell me it can't happen, I've lost too many good people that way! the above example is of guy I knew. I was there when they tried to pull his body out of the chair he was frozen into!

It's partially why I'm so firmly attracted to the concept of having all my base batteries set up as 12V with the ability to switch between 12V/24V/48V at will.

Worst case, if I run out of juice in the cold without enough to run the motor (wouldn't be the 1st or likely the last time); I can switch to 12V & use the remaining residual capacity (even if it kills the batteries, better them then me) to stay warm or signal for help.

In such a situation, I could probably flip a switch or unplug & replug a few wires but rewire my power systems? Not likely! It's the same reason I'm so obsessed with avoiding flat tires... But I'm making that part it's own thread cause this is long enough already. But check it out if you want to never deal with snake bites again...

Adam