Anyone ever crack an axle?

So this is probably my fault





Axle is drilled out to accommodate bigger wires, and the drive side was shortened last year (when I was an idiot) to keep it from rubbing the derailleur. Bike was running 22s with an 18 fet lyen.... probably maxing 8kw bursts....

Possibly, the clamping drop outs were overtightened too.


On the flip side, this proves how well clamping drop outs work..... cause I rode like this daily for a month.

It just sucks for a lot of reasons. Ya'll probably noticed I haven't been posting for the last month. I had a bit of a mental breakdown about school, money, finishing this damn bike, and of course a girl. I've spent the last month trying to work my self out of a pretty deep depression. I guess you can call it burn out syndrome. And now my finally finished bike is dead in the water, with no chance for repair, and no money for a new motor. Also I spent like HOURS modding that god damn motor. $T@#$%@%@

It's kinda funny actually. I hate that bike now. So much frustration. Want to set it on fire. Most of you would probably love that bike though. It maxes at 50mph, does wheelies, and handles like a dream. And it's rain proof with the batteries in a box in the triangle. Any one in the DFW metroplex wanna buy it? :lol:



Oh, and yesterday, the kickstand on my other bike broke


But the crowecycles people said they'd send me a new one (steel not AL this time)

Sorry about the bad luck.
It was a hell of a learning experience though,eh?
I know some motors have pressed axles,maybe this one is also pressed in.
If it is, you can order a new axle and have a machine shop change them out with an arbour press.Maybe some dry ice needed.
Check it out buddy..........remember all is not lost. 8)
At worst you got a good parts motor.

You have done some outstanding design and fabrication work and I want to compliment you on it!

I also would not be too concerned about the "cracked" axle. It looks like a machining flaw to me where the center bore and the machined flat got out of tolerance and you punched thru a very thin layer of steel. The good news is the steel on the bottom should be thicker than normal to make up for the thinner than normal top. If the axle is not bent, put her back together and run it like you stole it!

Stinks on the broken stand... but I have found that "problems" tend to cluster. In todays society we know so many people, and we do so much that it is easy for relationships and broken stuff to pile up, one on top of each other. When I was a kid all we had was one TV (black and white), a big rotary dial phone that sat on top of two phone books, and I had one 7 transistor radio. .. Fast forward to today, my two daughters came home from down state for Thanksgiving. One threw a router on my bench with, Dad this worked for 3 months and started loosing packets 5 days ago, the other showed me a broken cell phone she wanted fixed, their cars need oil changes, One laptop power supply needs a new connector from being tripped over. I think one started to talk about having lost a credit card... but I didn't want to listen to much more... not to mention that I found out 4 days ago that I now have a risk of 1 in 12 of cancer from a drug my doc put me on 12 years ago...

What I have found in my years is to play for the long game. Stay rested, stay upbeat, stay clear of constant downer experiences, be they people or bad products. Spend some outdoor time in the majesty of nature, the sounds of the morning, and the stillness of night. I get down too, but I never want to forget the great potential that we all have to get up in the morning, have some good coffee, and invent or create something that no one else has. You have done that with your bikes. Dwell on the good stuff, be with the good people, celebrate life and it's journey. One day you will look back with great pride and joy at what you have done for us all! Take care.

I've heard of it happening with drilled axles on Crystalyte motors. Dude... *that* sucks. i wonder if ebikes.ca could get you a replacement 9C axle however.. !

As for your torque arm/plate deal, i think maybe this could have been prevented by bolting the axle to the frame. Seems like you left it hangin'.. i see how there could be some unwanted motion in the axle.. just a theory though.

Sometimes life can be brutally tough. 'This too shall pass.'

Here is some advice that I have found helpful. It may work for you, it may not.

Stay away from alcohol it you suffer from bouts of depression. It's a dangerous drug, the most dangerous, and a depressant. It can lower you faster than a heavy punch to the temple. And unlike being punched, with alcohol you wouldn't even know you have been hit until quite awhile later.

Be kind to yourself. You wouldn't treat a friend poorly and give out to them for petty, meaningless stuff - so don't treat yourself badly. Be careful what you say to yourself and be your own best friend.

Lower your expectations from life. Depression results when the disparity between your ideal self and your perceived actual self becomes too great. Keep it in balance - the reality is that no one lives up to high, unrealistic, expectations. When you brush away the hype you will see that this is true of every single human being that ever existed. If you have lofty goals - you need to set smaller milestones to aim at along the way. Most of the time you will hit them.

Perfectionism is overrated. No one actually ever wants to hit perfection. The rest of your life would be pointless if you achieved what you were striving for to the full degree. The thrill is the pursuit the destination is worthless.

Great attitude, Big Moose! One we would all benefit from emulating

As someone with experience trading axles on older 9C's I don't recommend it. Too much work and I was at the limit of axle thread strength using the axle threads to pull the axle out of the stator using cut to length pipe spacers and a torch applied to stator hub. I agree with Big Moose that unless it is bent or has cracks running 90 degrees to the one shown in your photo run it the way it is. The likely failure point will be at the inside edge of the bike dropout where axle diameter increases to enter the motor bearing.

Your motor windings look great. Overheated 9C's usually have "browned" windings.

Guys, thanks so much for the kind words. It's amazing how "strangers" on a web forum can be better than most of my friends and family. Treating yourself right and a positive state of mind is what is getting me through this. I'm learning to control my thoughts, and slow down and enjoy the small things (that are actually the big things in the grand scheme of things!) Meditation to shut down negative thoughts or when my mind goes on unproductive tangents about ebikes or problems. Part of the problem was the ADD meds I was on WERE straight up amphetamine, and they had me running around, perpetually stressed out. Worked fine while my brain could handle it, but eventually I could barely get productive work done. I remember spending 2 hours trying to crimp one 4s JST connector, and pretty much frocking it up completely and getting so angry. Turns out constantly having adrenaline in your system actually damages your brains ability to regulate stress hormones. This is "burn out syndrome." Been reading a lot about depression, and neuroscience. I never made the connection between, stress, ADD, and depression before.

Nice notice on the windings been new and still crisp. Only a few hundred miles on this motor with the new setup. It's pimped out with temp sensors, upgraded phases, and ventilation. Really don't want to lose all that work. Especially when I haven't even cooked at yet. Max was 130c

I think 90% of the problem was my fault: I didn't keep the drill straight (not a drill press, but a hand drill) and it drilled at an angle. The other side of that axle is perfectly fine. Ok, so maybe I can continue running it. Perhaps with more clamping force on the thicker drive side to take tension of the hollow brake side. Mode of failure will be it snapping where the axle expands to enter motor... which would be bad. That part is unsupported by the bottom plate, so perhaps I can epoxy a shim down the length of the cracked side to provide additional support. Or I maybe I should flip it?

hate to be debbie downer here but that axle scares me. If you're gonna ride that bike still, do us all a favor and wear a helmet.. and maybe cut the amps down a tad while you're at it. maybe some doctorbass style DP-420 metal epoxy might be of help here.

As for the mental illness bit, get to know enough people on this forum and you'll notice that we're all a bit wacked in the head. I definitely fit a few DSM-IV criteria. We are sort of a cross breed between bicyclist, early 80's computer nerd, and adrenaline junkie. How does all those things exist in one person without them being a bit off?

I wouldn't have it anyway. This community is rad.

I agree with all the above.. In the last few years I have become at peace with myself with some kind of balance that's hard
to describe. You seem like a good guy and I enjoy reading your posts. I am glad that you are being honest with yourself
and that should help a lot.

You do good work so just keep at it - nothing better then a goal to keep you focused.

thanks for sharing.

Agree with the notion that ya now got a parts motor.

re: focus and frustration:
http://www.webmd.com/balance/news/20111120/meditation-may-help-brain-tune-out-distractions

Well, I'm not a mechanical engineer, get an opinion from one. However considering the stresses that axle is under, it doesn't seem to me that crack would weaken it much in those directions. Also this is mild steel which has good gradual failure modes. Keep an eye on it, keep it snug, get some more opinions and ride it gently unless the experts say otherwise. Build up gradually and get confidence and experience with it.

Here is a thought....

Get one of these : http://www.mcmaster.com/#hex-coupling-nuts/=f2h4hu (13mm?), drill holes through the sides. Fill holes with a welder.
With longer bolts your torque are should clamp just as good to it.

I don't see the forces involved causing a problem even if the axle was cracked along it's length on *both* sides, unless you are jumping the bike with no rear suspension (or a lot of unsprung weight...which the motor might amount to), off foot-high or greater height differences. It's a rear axle so even if it did break the worst I can imagine happening is the tire dragging the wheel to a near-instant stop against the frame, causing you to skid on the rear wheel. That kind of thing is easy enough to control in most situations, compared to any similar front failure.


The only thing I would do with it is put a nut on it as close to the middle of the crack as I could, considiering wherever the clamps go and the dropouts and such, as the nut surrounding the axle will compensate for any tendency for the split to be pushed apart by twisting/clamping forces on the flats.


I can't imagine it being possible to have the clamp plate itself "too tight", if it's forces are all parallel to the flats of the axle, it should pass that force thru the arched part of the axle to the other side, evenly, and not be pressing the cylindrical section in a way that transfers anything thru the now-cracked part in a way that would do that. But twisting motions of the axle (which still happen, between the inboard edge of the clamp itself and the stator's mount to the axle) could transfer force in a way that *would* do that if it was thin enough and brittle enough.


The only possible thing that would concern me is if that crack has also propagated along the stress riser that is where the dropout would normally sit against the slightly larger diameter of the axle inboard of the flats. I can't see in the pic if it has or not. Myself, I would still use the axle, even then, but I would first pull out the wires and then weld a spot into the propagated crack on the stress riser, so that it can't continue to flex at taht point and break later. Welding would change the heat treatment of the area, but I would consider it safer than having a crack along the stress riser there. Even so, it's still a rear, whcih is way better than a front failure in a similar way. :lol:

Part of the problem was the ADD meds I was on WERE straight up amphetamine, and they had me running around, perpetually stressed out. Worked fine while my brain could handle it, but eventually I could barely get productive work done. I remember spending 2 hours trying to crimp one 4s JST connector, and pretty much frocking it up completely and getting so angry. Turns out constantly having adrenaline in your system actually damages your brains ability to regulate stress hormones. This is "burn out syndrome." Been reading a lot about depression, and neuroscience. I never made the connection between, stress, ADD, and depression before.

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I hear you, I have a big box of those ADD tablets...200mg each. Great for the 1st 2 days but I have had to regulate myself to just 2 a week otherwise my brain just goes nuts. It's like Cocaine without the fun horny part lol.

Then again I am totally focused for those few days I do take it, but noticed the burnout effect creeping up so only take them with 3 days in between. Shit seems to come in three's... but like the wise men on here have said the beauty is in the small things and also the journey. Oh and girls.....there will always be another, it just never seems like it at the time...might take a few months ...shit it might take a few years but best to get to know yourself in the time when you are single. Think of it as a relationship holiday and sort your head out

Oh and I totally agree, internet friends are able to be so much more honest and open with their feelings because of the anonymity that people you see each day do not have.

Oh, I get it. You drilled out the axle. That's how it got so thin. I've heard of twisted axles on x5's, but not cracked since the axle isn't hollow.

ADD didn't exist when I was young, but I'm pretty sure I had something. Made C's and D's till I started smoking pot. ( haven't needed it in decades now) Next thing I know, I'm in honor society. I garantee no studying or trying harder was involved. It seemed to slow me down just enough to absorb someting. Absolutely everybody else smoking dropped a grade though.

hate when lathe happens... ;_)

Cocaine without the fun horny part lol.

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Oh I disagree, and so do all of the girls I've dated. They all loved it when I took my medicine.....

AW, thanks for the breakdown - it's not cracked around the edges there, so I think it should be fine if I run it. Just no more jumping off curbs or hard off roading like I was doing at first.
If I disappear for a few weeks again and neptronix hasn't heard from me on facebook, I guess you can assume it was maybe a bad idea to run it. I forgot who's in my ebike will, so it'll be a surprise who gets what

JK! Full face helmet, etc. etc.