PaPaSteve
1 kW
This guy does the best job of explaining the science behind wheel building.
https://www.youtube.com/user/BillMouldWheels/videos
https://www.youtube.com/user/BillMouldWheels/videos
Custom length spokes and bending your own "J" end
- Thread starter cloudy
- Start date
I'll watch that one as time permits...but while I'm no expert, I know a fair bit about the idea behind it, and have some experience with buildling my own wheels (including failed experiments 
). 
I was curious about the specifics of your thinking on the difference between the wheels I have that work vs this one that failed....
). I was curious about the specifics of your thinking on the difference between the wheels I have that work vs this one that failed....
PaPaSteve
1 kW
Visually, from the pictures you provided, the wheel doesn't appear to have enough spokes.
The is measured against 25 years of handcrafting a wide variety of mostly human powered vehicles ... a few were electric, or fuel powered.
i.e. I've laced a lot of wheels.
Perhaps luck had a hand in why one wheel worked and the next wheel failed.
The is measured against 25 years of handcrafting a wide variety of mostly human powered vehicles ... a few were electric, or fuel powered.
i.e. I've laced a lot of wheels.
Perhaps luck had a hand in why one wheel worked and the next wheel failed.
LewTwo
1 MW
This is actually a group of videos. It is going to take a while to view all of them.PaPaSteve said:
One of those videos demonstrates mounting a bicycle wheel on a Toyota Corolla. He states the weight on the wheel is 500 pounds (sounds like a rough estimate). That was a 36 spoke wheel. https://youtu.be/sZ7dtrRrSTg
He also has a Web Site: https://billmouldwheels.com/
I don't have anywhere near your experience in wheelbuilding, and I trust an experienced eye, which is why I asked for the details of your thoughts on this failure.
I don't doubt I could build (significantly) better wheels, more spokes probably would help, but it's not just one wheel that worked on this trike. It's several, all of which experienced much more severe conditions and much heavier loads, for longer, than this one, and none of which failed (discounting a single spoke failure at one time or another).
I've done plenty of heavy cargo hauling (up to and including a piano on a DIY trailer with four different typical 26" bicycle wheels in side-by-side pairs, though the trip was pretty short, only a couple of miles) with various sized wheels on various bikes, trikes, and trailers, both before I came here and started electrimotorificating things, and after, almost all of them just common 36-spoke bicycle wheels, most of which I didn't build or rebuild, some of which were pretty crappy, and none of them failed like this--the worst failure I can recall (not counting one destroyed from motor torque via chain derailment) was when I used a solid-tube rear wheel on DayGlo Avenger, and it literally just beat the wheel to death fairly rapidly..even then it just loosened the spokes and deformed the rim, didn't break them like this.
That's what leads me down the path of this specific wheel being problematic in some way that led to the failure, some way that is different from the wheels I built, that I hope can be analyzed and determined with some reasonable certainty.
I'd like to figure that out so I can ensure I never do whatever was done in building this wheel by whoever built it. Also because I usually have a "burning need" to know why any one specific thing failed in whatever particular way it did. (I probably missed a good career in failure analysis. :lol: )
Anyway, I disassembled the broken wheel and took pictures as I went. I'll write it up and post it in the other thread and link it here once I get that done later tonight.
I don't doubt I could build (significantly) better wheels, more spokes probably would help, but it's not just one wheel that worked on this trike. It's several, all of which experienced much more severe conditions and much heavier loads, for longer, than this one, and none of which failed (discounting a single spoke failure at one time or another).
I've done plenty of heavy cargo hauling (up to and including a piano on a DIY trailer with four different typical 26" bicycle wheels in side-by-side pairs, though the trip was pretty short, only a couple of miles) with various sized wheels on various bikes, trikes, and trailers, both before I came here and started electrimotorificating things, and after, almost all of them just common 36-spoke bicycle wheels, most of which I didn't build or rebuild, some of which were pretty crappy, and none of them failed like this--the worst failure I can recall (not counting one destroyed from motor torque via chain derailment) was when I used a solid-tube rear wheel on DayGlo Avenger, and it literally just beat the wheel to death fairly rapidly..even then it just loosened the spokes and deformed the rim, didn't break them like this.
That's what leads me down the path of this specific wheel being problematic in some way that led to the failure, some way that is different from the wheels I built, that I hope can be analyzed and determined with some reasonable certainty.
I'd like to figure that out so I can ensure I never do whatever was done in building this wheel by whoever built it.
Also because I usually have a "burning need" to know why any one specific thing failed in whatever particular way it did. (I probably missed a good career in failure analysis. :lol: )Anyway, I disassembled the broken wheel and took pictures as I went. I'll write it up and post it in the other thread and link it here once I get that done later tonight.
PaPaSteve
1 kW
For a brief 3 year period I was doing stress testing for this company :
https://x.company/projects/makani/
It was physical tests to back up the engineering staff's computer simulation tests.
Plenty of broken stuff.
For inspiration ... compare the spoke details of small, slow moving motorcycles to what is on your rig.
View attachment DC cop.JPG
I've done a few heavy weight rigs too.
Not seen in this picture is a trailer loaded with a bunch of people on it being towed.
The trailer failed a wheel a few feet after this picture was taken.
The tire slipped off the pavement into the grass and instantly collapsed.
https://x.company/projects/makani/
It was physical tests to back up the engineering staff's computer simulation tests.
Plenty of broken stuff.
For inspiration ... compare the spoke details of small, slow moving motorcycles to what is on your rig.
View attachment DC cop.JPG
I've done a few heavy weight rigs too.
Not seen in this picture is a trailer loaded with a bunch of people on it being towed.
The trailer failed a wheel a few feet after this picture was taken.
The tire slipped off the pavement into the grass and instantly collapsed.
Ouch.
I've typed up the post
https://endless-sphere.com/forums/viewtopic.php?f=2&t=67833&p=1736701#p1736701
but the pics are still uploading, I expect it will take about 10 or 15 more minutes for those to finish. they are original resolution if you click on them to expand; if better pics can help I'll do what I can to get some.
I have a theory (that is probably bunk) in the post for a potential specific failure cause, if you could check it out and let me know what you think.
I've typed up the post
https://endless-sphere.com/forums/viewtopic.php?f=2&t=67833&p=1736701#p1736701
but the pics are still uploading, I expect it will take about 10 or 15 more minutes for those to finish. they are original resolution if you click on them to expand; if better pics can help I'll do what I can to get some.
I have a theory (that is probably bunk) in the post for a potential specific failure cause, if you could check it out and let me know what you think.
I hope I didn't confuse anyone when I wrote this little bit of nonsense:
I suspect using a hub with paired holes for zero cross spoke pattern will give better spoke angle versus a hub with regular holes. So the paired holes reduce peak force when torque is applied to a radially laced wheel. I think I've seen a few wheels like this on the forums and did not notice the paired holes.
Only one length of spoke will work for a given rim/hub combo and spoke pattern. So zero cross will mean 90 Degree spoke angle unless the hub (or rim) has paired holes. The Grin Spoke Calculator was useful for improving my understanding.cloudy said:
I suspect using a hub with paired holes for zero cross spoke pattern will give better spoke angle versus a hub with regular holes. So the paired holes reduce peak force when torque is applied to a radially laced wheel. I think I've seen a few wheels like this on the forums and did not notice the paired holes.
I did make 18 Z bend spokes to lace my motor into a 24 inch rim. I already had enough standard spokes for the drive side. The z bends seemed to tension up fine, and none pulled through.
I drilled a 2.5mm hole in a steel plate to help bend the spokes, and also used my bench vice to make the bends.
I found lacing the Z bends with elbows out was more secure, and it interferes less with the motor side covers should I have to remove those in future. Elbows out arguably will build a stronger wheel anyway.
I'll post here in future if I have any failures or issues with this wheel. Thanks everyone for your input.
I drilled a 2.5mm hole in a steel plate to help bend the spokes, and also used my bench vice to make the bends.
I found lacing the Z bends with elbows out was more secure, and it interferes less with the motor side covers should I have to remove those in future. Elbows out arguably will build a stronger wheel anyway.
I'll post here in future if I have any failures or issues with this wheel. Thanks everyone for your input.
