Cracked side casing on Crystalyte 408motor - Strange Failure

[Sacman]

Arrrrrrggghhhhh!!!

Earlier last evening the side casing of my Crystalyte 408 hub motor cracked. The loacation and the way it cracked is very strange. It cracked at the base of the threaded part (where the 7-speed freewheel screws onto). I’ll be contacting Crystalyte to see if they will warranty this.

Now if Crystalyte ends up not honoring the warranty I'll have to find another hub motor cover plate (with threads for the 7-speed freewheel) from somewhere else. Does anyone know of a source for this side cover plate?

At least one person told me the same thing happene to them on their X5 motor and so now I'm wondering if this type of failure is common or not to Crystalyte motors or hub motors in general.

Here are the details of how the hub motor cracked on me while riding home from work yesterday: ****************************

The cracked hub motor casing happened at a complete suprise to me. I did not jump off or over any curb. I'm just pedalling normally on the road, travelling about 25mph, going home from work. All of a sudden I feel the pedals go loose. It almost felt like the chain broke loose... but there was no chain rattle. There was a rubbing-shaking feeling coming from the back wheel and so I stopped the bike to take a look.



I inspected the back wheel and found out that the 7-speed cassette freewheel was no longer connected to the rest of the rear wheel. It was still connected to the threaded portion of the hub but that part of the hub had broken off. It was pushed up against the rest of the wheel and making a very weak friction contact but I was able to spin it freely when I turned the pedals.



Ugh! ... I got on my cell phone and called my brother to rescue me. He drove his car to pick me up. I was still 9 miles away from home and I was't going to push the bike all that way.



So when I get home I removed the back wheel. I unscrewed the nuts and washes from the rear axle and the 7-speed freewheel with the broken threaded part of the hub came off.



I had to use a large Channel-Lock pliers to hold the broken threaded part of the hub while I used a spline tool to separate it from the 7-speed freewheel. It took a little doing but I finally separated the two.



I took some pictures with intent to contact Crystalyte and show it to them to see if they will warranty the broken hub motor.



That's it... that's all that happened. It cracked but I don't know why. I was pedalling normally (like I always do) on the street and it just cracked. I can't explain what could have happened to cause it to crack. The bike was riding fine and in top shape the past week too.

 

[pwbset]

Do you run your 408 hot a lot? I'm beginning to think that metal fatigue on this cheap metal is a real issue. I run my 4011 very hot and it's maintained all it's power etc, but I pop spokes all the frickin time at the motor (with perfectly trued wheels and on pavement/level ground even they will pop) and upon inspecting the breaks am noticing that the Clyte metal/casing etc. looks to be very poor quality. It grooves very easily etc. Might just be you identified another weak spot if heat plays a role. Dunno.

 

[Sacman]

I'd say my 408 motor gets fairly warm to the touch ... but not hot. Even when I've just finished a long uphill climb I've felt my battery and my motor. They're both warm, but again ... not too hot so that it's uncomfortable to keep my hand on them for a while. I guess it's got a lot to do with the fact that I only have a 20A controller. BTW I'm running it at 48V too.

 

[Zoot Katz]

That type of failure is mentioned on the ebikes.ca Troubleshooting page. (Scroll down to #8)
http://www.ebikes.ca/troubleshooting.shtml
They previously had side casings listed in the store but I can't find them now.

 

[Sacman]

Ahhhhh... much thanks Zoot Katz. The failure IS documented somewhere. Makes me feel a little bit better that I didn't do anything out of the ordinary to cause it to fail .

 

[Ypedal]

Yep.. i've had a customer locally who had a similar problem...

I have a pile of spare covers if you need one.. shoot me a PM ( cover shipping and i'll send it )..

Cheap metal and poor QC... not likely anything you couuld have prevented.

 

[lawsonuw]

The crack location looks like a spot that's highly stressed while pedaling in top gear. It's most likely a fatigue failure. The cheap casting likely contributed to the demise. It would be hard to find this now, but I bet the crack started around a piece of sand, grit, or a nick in the metal around the area of the crack.

Marty

ebikes.ca should be able to get you a new cover.

 

[dnmun]

that casting is very thin at the section where it fractured. is the inside also cast or is that part machined out? it could have been damaged when machined and did not fail until you had 'worked' it through the freewheel torquing it. or it could have been damaged when the freewheel was installed too. i know bill was able to buy a used replacement hub side, the other side from yours, from justin at ebikes.ca.

don't throw it away without trying some J-B weld though unless the bearings interfere inside. it will take multiple layers to build it back up though, maybe reinforced with a steel ring in the epoxy on the inside.

this would seem to be one of the best arguments for the front hubs if they are so fragile on the freewheel stub.

 

[Sacman]

Yep.. i've had a customer locally who had a similar problem...

I have a pile of spare covers if you need one.. shoot me a PM ( cover shipping and i'll send it )..

Cheap metal and poor QC... not likely anything you couuld have prevented.

Oooooooh! That's frickin' awesome Ypedal....
You're frickin' awsome....
And didn't I mention ...this forum is frickin' awesome.
That'll be great, I won't have to wait for an answer from Crystalyte about honoring their warranty. I'll PM you right now. :wink:

 

[swbluto]

I honestly hate Crystalyte's lack of quality casting(And the cheap metal used) and inconsistent quality control. I originally purchased the Crystalyte thinking it was an "upgrade" from the Golden Motor and thinking it'd be oh so durable foooooreeevvvveeer(And I paid about $200 extra for it, so I thought the quality would've reflected this), but I quickly abandoned my notions at 400 miles when a spoke popped a part of the flange off(Where the spoke connected to the hub) and I haven't been riding since(Way to go! Woohoo! And I still haven't got a response back from ebikes.ca for three weeks! Yeah! Customer service, way to go! Guess I'm going to have to send a new email! ). I can't wait until economic evolution weeds out crap-offerings such as these.

 

[Sacman]

I agree. A few months ago I would have thought the same... that Crystalyte equipment was "the good stuff" as well. But looking back on the problems I've had with:
1) cheap spokes keep breaking
2) controller's throttle circuit got stuck on WOT
3) NiMH battery internal wiring came loose
4) and now... hub motor side plate cracked
...I can no longer say that Cryatalyte quality is really all that good.

About the only thing that Crystalyte has going for it is that it has a fairly big knowledge base of users where you can get lots of help for troubleshooting problems or making modifications to the equipment.

 

[pwbset]

About the only thing that Crystalyte has going for it is that it has a fairly big knowledge base of users where you can get lots of help for troubleshooting problems or making modifications to the equipment.

They seem to be one of the few (only??) brands out there that can take massive over power abuse and keep on ticking. I has serious mis-givings about running a 4 series at 84v and 40a+, but almost 1,000mi in it's still humming along nicely (though hotly :lol: ). I wonder what other comparable motor to a 4 series can handle 2kW sustained for extended periods without self-destruction?

 

[Ypedal]

Crystalyte has been around for a long time, and they have been staying alive, all things considered... there are worse things out there. Problem with clyte is that it has not evolved over the years, others have stepped up and improved while Kenny has been pumping out the same old motors, tried, tested and true..but not any better. Don't even get me started on the controllers..

I have personally never broken a single spoke, and it's not because i ride like a sissy either.. ... I have built a few so far, and have learned a few lessons, stiff rims, and moderate dishing, spokes as tight as possible, works for me.

Broken spokes at the hub flange are either victim of an insufficiently stiff rim, spokes not tight enough, holes at the hub drilled too alrge for the diameter spokes used, incorrect lacing, excessive dishing, etc... alot of factors to consider here..

motor covers failing however.. that's just wrong.

 

[swbluto]

Broken spokes at the hub flange are either victim of an insufficiently stiff rim, spokes not tight enough, holes at the hub drilled too alrge for the diameter spokes used, incorrect lacing, excessive dishing, etc... alot of factors to consider here..

It wasn't the spoke that broke: It was the hub flange.

 

[pwbset]

Broken spokes at the hub flange are either victim of an insufficiently stiff rim, spokes not tight enough, holes at the hub drilled too alrge for the diameter spokes used, incorrect lacing, excessive dishing, etc... alot of factors to consider here..

..riding hard scrabble off road single track washboard at 35kmh+ daily with excessive motor heat fatiguing the cheap metal.. :wink:

 

[swbluto]

Broken spokes at the hub flange are either victim of an insufficiently stiff rim, spokes not tight enough, holes at the hub drilled too alrge for the diameter spokes used, incorrect lacing, excessive dishing, etc... alot of factors to consider here..

..riding hard scrabble off road single track washboard at 35kmh+ daily with excessive motor heat fatiguing the cheap metal.. :wink:

Are you sure you're in Montana? I thought imperial units were... like... used everywhere in the US. Maybe my assumption is unjustified?

 

[pwbset]

Are you sure you're in Montana? I thought imperial units were... like... used everywhere in the US. Maybe my assumption is unjustified?

Just trying to fit in on the global stage man! Besides Canada is only 62mi... er... 100km up the road. :wink:

 

[swbluto]

Are you sure you're in Montana? I thought imperial units were... like... used everywhere in the US. Maybe my assumption is unjustified?

Just trying to fit in on the global stage man! Besides Canada is only 62mi... er... 100km up the road. :wink:

Hehe. Yeah, I think the metric system is so superior(mainly because I deal with physic's calculations!), I'd join to if it weren't to satisfy those stuck in the imperial age.

(I was really questioning whether you originally moved to the US from Canada.)

 

[nic]

I feel obliged to post this. The same incident with the thread falling off happened to me twice! Here's my story:

In august this year I bought a Crystalyte 406 motor (M406RD26), a 35A controller and a thumb controller from ebikes.ca. The motor is of the kind where you can fasten a disc brake disc on one side of the motor, and a threaded freewheel on the other side of the motor (different from the M406R26 model). The two side covers mounted on each side of the motor are equally sized. It means you can switch the covers when the freewheel-cover fails (It includes more work than removing the screws).

I recieved the package from ebikes.ca september this year and mounted the kit on my bike. For some days the kit worked great. But one day the applied pedal force would no longer push the bike forward. I demounted the rear wheel and found this:

The force generated by my legs where apparently enough to break the thread free from the side cover. After some struggle I managed to switch the covers, meaning I would no longer be able to mount a disc brake disc. However, I could now apply the pedal force again and operate the e-bike as it should. Reading the posts here at endless-sphere I got the impression that this was not of the normal incidents, and that it most likely wouldn't happen again. I was wrong.

The bike worked normally with the covers switched for maybe a month. Then, I got the same feeling as I did with the first incident: The applied pedal force would no longer push the bike forward, and I heard the same grinding noise when pedalling. I knew too well what was happened. My days as a ebiker were over, for the time being. This time the hole was even bigger, like sacman's motor:

The last image show the leftover parts from the two side covers. They actually snapped at different places. The motor is so soft you can make carvings in it with a kitchen knife. And after a couple of these incidents you get the impression that the motor is made of butter.

I had a small hope of mounting the rear motor on the front wheel now that both of the covers were threadless, but no. The dimension of the motor axle did not fit with the front fork. Not without massive grinding on the axle.

Over all, the Crystalyte 4-series are really quiet, and I wish the metal quality was better. For now my advice after a couple of months is:

- Do not buy Crystalyte rear series 4 motors. The front series on the other hand do not have these issues.

nic

 

[pwbset]

That sucks nic. Ebikes.ca warranty??

 

[Ypedal]

:lol: yikes.... :|

If you don't mind my asking, how much do you weigh ? Do the bearings look/feel seized up ?

I still have a pile of these in a box if you need a pair, check with ebikes first tho.

 

[dnmun]

do you pedal hard a lot with the chain on the 11 tooth end of the freewheel? i wonder if the load exerted on the end of the freewheel can be twisting the neck of the hub where it extends out. the constant torquing could start stress cracks at the base of the freewheel threads and eventually just fail through fatigue cracking. it would seem that the outer bearing would take up that load so the base of the stub should not be suffering from that kinda stress. you don't do the jumps and other stuff i assume, that could be overloading the axle when you land?

i bet justin will help you out, but if this is a recent motor, this could be a new problem that the older motors did not show.

 

[Sacman]

Hey thanks for sharing your story and pictures Nic. I got some gracious help from Ypedal, who sent me some side casings that he had and I was able to get my 408 motor up and working again. It took quite a bit of machining to make his parts work for me but I eventually got one of them to work. I hope you can get yours repaired also let me know if you need any help. On the othere hand, if you don't want to take on the machining work and just want to sell off your 406 motor let me know too.

 

[Sacman]

do you pedal hard a lot with the chain on the 11 tooth end of the freewheel? i wonder if the load exerted on the end of the freewheel can be twisting the neck of the hub where it extends out. the constant torquing could start stress cracks at the base of the freewheel threads and eventually just fail through fatigue cracking. it would seem that the outer bearing would take up that load so the base of the stub should not be suffering from that kinda stress. you don't do the jumps and other stuff i assume, that could be overloading the axle when you land?

i bet justin will help you out, but if this is a recent motor, this could be a new problem that the older motors did not show.

Hmmmm.... you know this got me thinking. The new motor casings ARE DIFFERENT from the older ones. I noticed that Nic's side casing has a 6-bolt hole pattern (just like mine). The older side casings that Ypedal sent to me have an 8-bolt hole pattern. I actually had to drill and tap 6 new bolt holes in my hub to make the Ypedal's older side casings work for me. It was difficult and a pain-in-the-ass. I broke 2 taps in the process.

They also have DIFFERENT DIAMETERS as well. Ypedal's older side casings were 2mm larger than mine. I ended up chucking the older casing up to my drill and spun it like a lathe while I used a file to slowly grind off the extra 2 mm from the diameter.

Anyway the repair did work and I was able to use my old 408 hub motor on my 2nd ebike build. The repaired 408 hub motor found a new home on my brother's mountain bike... a 2006 Mongoose Blackcomb.

 

[nic]

That sucks nic. Ebikes.ca warranty??

I hope so.

If you don't mind my asking, how much do you weigh ?

About 230 pounds.

Do the bearings look/feel seized up ?

The bearing on the fragment from the cover rotates and feels normal. I don't know about the bearing on the other side.

do you pedal hard a lot with the chain on the 11 tooth end of the freewheel?

I actually use the smallest outermost wheel on the freewheel almost all the time when biking around. I normally use the two highest gears at the front when riding on the plain. I switch to lighter gears both at front and at rear when I meet hills.

you don't do the jumps and other stuff i assume, that could be overloading the axle when you land?

I try to ride the bike as normally as possible, but at my way to work there are some bumby places. I try either to avoid them or slow down at those places.

On the othere hand, if you don't want to take on the machining work and just want to sell off your 406 motor let me know too.

I think i'll wait until further notice about selling the motor. If I can get a hold on a bunch of replacement covers I will have a supply (hopefully)for the lifetime of the motor, until it eventually dies from the corrosion death.