You are a good man Jeff. I mean it.
6 Likes
I mean, you have to see my point a little bit right? 
I can go to home depot, buy a wooden rod and a drill bit, 5 minutes and voila, kegel core clone.
Like have some creativity in the spoke design. Circle of holes? Really? That’s the best they can do?
1 Like
For me, the simpler the design the better. I just want to ride freely without thinking about the quality of my wheel cores.
6 Likes
I think everyone is an important contributor, especially you.
4 Likes
I get that. But I’m with the philosophy that rims make or break a car. Get a lamborghini and throw some steel honda civic rims on there. Now it looks like crap.
2 Likes
Is not material problem because of shape of core either material if PC or PC/ABS or GF it still can having this problem.
Core is support too much mass for wheel. Problem can be fix in 2 way.
- Increase thickness of core spoke so have more material. It can fixing but still May cause breaking. Need FEA and further testing for load.
- Change core design to more solid core to supporting material loading better.
Because this wheel is compress great for having foam mix with PU it cause excess load to core more than other wheel. This why normal wheel with this core not having same breaking problem.
8 Likes
That I cannot argue with.
2 Likes
I only think gf nylon will be more durable long term. PC/ABS has much lower fatigue life than gf nylon, after wheel use for a year, pc/abs more likely to break
1 Like
But gf have no good impact resist. It can shear and breaking with force. I think because of shape and stress load it still have this problem and maybe worse with GF. It can be also fix by add some reinforce to existing PC/ABS. Maybe 10%.
2 Likes
Edit: Ignore this post. A week later another thread contributor enlightend us all that conventional cores are made from TPU, not Nylon, Not Nylon & GF. Nylon & GF was some misinformation./Edit
Tensile strength means little here. you know what else has high tensile strength? glass. You wouldn’t use a glass core would you?
Flexibility, compression, fatigue, many factors needs to be considered. For a wheel, a bit of flex could be the difference between bending and springing back, or cracking.
1 Like
Tensile is not same as impact resistance. Nylon/GF have low shearing force and can easily shear.
1 Like
Edit: Ignore this post. A week later another thread contributor enlightend us all that conventional cores are made from TPU, not Nylon, Not Nylon & GF. Nylon & GF was some misinformation./Edit
But Glass Fiber doubles all of the following propertied for Nylon + GF:
tensile, elastic, yield and fracture strength
1 Like
No it doesn’t. Which type of Nylon is use? PA6? PA66? Or maybe even PPA? Is nylon use from DuPont or other supplier? Not many can getting DuPont in China unless working in car industry.
1 Like
You could also do glass fiber PC/abs too.
1 Like
Edit: Ignore this post. A week later another thread contributor enlightend us all that conventional cores are made from TPU, not Nylon, Not Nylon & GF. Nylon & GF was some misinformation./Edit
The research was done on PA6. Look at all five charts.
Yes friend, we know all about chart. But having work in manufacturing for more than 20 year, this is meaning nothing unless you actually making and testing in real life with real product. How is injection mould also play big part, how is part cool? What is shrink rate? Is many factor involve in this, not simple graph! Which standard is mould making to? Which material is use for mould? …
These test are perform with not real life part. Is just make block and testing. This not real for testing because shape of finish item play big part for strength, is no way to use graph to know strength for all.
6 Likes
Do you think carbon fiber core would be strong, or would it crack? I feel like it is too brittle. It would look cool.
No it crack baddddddddddddddd
5 Likes
Hahaha. That’s what I was thinking. Too stiff and brittle. Lot of tensile strength though. Doesn’t mean much… Case in point.