Grade 8 is also a really good grade for KP bolts, this is what we use on Magnetic
5 Likes
mind that you dont grow a trama induced cyst on your hip. I grew one there ,larger than you can imagine,it wont go away if it gets going
Do you have any that would work as replacement KP’s on these stock death pins if we wanted to replace them?
I can see three different things going on across the surface of this break.
The blue sections show a series of cracks leading from the splines. They all travel in the same direction. Those areas appear darker, like oxidation had occurred. They may have been hairline cracks for some time.
The two uncoloured sections are clean, no oxidation apparent here, this may be the final break that cause the crash.
The red section which is a result of cracks coming from both sides simultaneously on different planes, they were not going to meet perfectly so the last bit let go like that.
3 Likes
Now if we go back to this pic we can confirm the orientation, the cracks come from the sides of the board.
It could be random, but the side loading of carving could have been a factor.
3 Likes
I’ve lost track of just how many miles or Km I have on my unbranded Chinese RKP trucks, but I know it is above 1000 Km.
So I’m not sure this is the case for all Chinese trucks in production or that have been made.
I think this will depend highly on the company offering it and the design of the board and the parts used. My first board was a midlevel price entry board and aside from the battery all the parts have held up very well even with a lot of daily riding, and riding in bad weather conditions. (not counting consumables like hub motor sleeves and wheels, but with the wheels they’re still perfectly usable if you don’t mind it being smaller)
I do think in general that people should be wary about getting an entry level complete board and that they should expect to need to replace at least one major part within a year of buying one.
What really sucks is that a lot of companies will make changes to where they buy parts from but still call the board the same model name. Making it impossible to recommend any specific China based company since the new parts may end up being worse than the original ones used.
1 Like
Hope you have recovered and well bro.
Mine just snapped on me while braking. Fortunately it was low speed. I put over a 1000 miles on my board. You guessed it, it’s a spline kingpin.
We got to remember where using skateboard components on motorised boards. An old Ernesto yt interview made me think. He pointed out the amount of forces being applied by our motors has an impact on both deck and hardware. Skateboard hardware was not set out to have motors that deliver high torque and rapid braking with a heavy load on board. That’s alot of stress running through the board.
I’ve ordered those aviation grade bolts you mentioned. Did you pick them up? If so what’s your thoughts on them? I’ve ordered some automotive grade bolts as well.
Keep rollin!
I have never had a kingpin that’s splined like that, seems like it’s a failure point… why is it there ?
Miles logged aint the crux. I take off slow, and brake minimal. I have pneumies. My deck has flex. I have poly pads under the baseplates. I do all these things TO treat my parts gently, Oh, and I stay slow.
Press fit…
Fast accel and brake more fun tho
This happened yesterday. A Flipsky truck. I use these on rental board, and I simply can not have this kind of failure. Luckily it was me on the board and it was a slow snap where the truck all of a sudden got real loose and I could stop with nothing happening.
Problem is that it seems that the kingpins are not that easy to get out of the baseplate for replacement.
If I find a way I will change kp all all 16 boards.
Get the baseplate off and heat it with a blowtorch. That will loosen up the tolerance while the metal is hot. Then it will be easier to hammer it out.
edit: make sure to get the pivot cup out before you apply any heat!
2 Likes
If kingpins are breaking, changing them every megameter is NOT the solution. The solution is to not use the kingpins that break.
1 Like
I also had this same thing happen many years ago on an Evolve branded Chinese DKP truck, and discontinued using them. I haven’t had it happen again.
I think what we are missing is, that DKP trucks have a longer lever arm and more violent twisting.
I have even read that mall grabbing causes the KP to break. That seems a little paranoid. The TI ones are only 17 per pair. Seems pretty cheap.