- This is a plastic seatpost collar
that I designed in Tinkercad,
and it has the distinction of being
the least sketchy thing we have here today.
That's right. (gentle upbeat music begins)
Not only is this stuff all made of extruded plastic,
but it was designed by yours truly.
We're gonna be testing it all on a bike today,
and we're gonna start small.
We're gonna play it safe
and then move on to more crucial stuff.
But first I'm gonna set a few ground rules.
So all the parts were made right here on my 3D printer.
They're made of PETG filament.
And although the parts are plastic as you can see here,
I have a piece of metal hardware in here.
It's an M6 bolt.
However, I did design these
to actually resemble real alloy bike parts.
I didn't 3D print a big, strong one
to try and make up for it.
It's just a plastic version of what you'd use on the bike.
So without further ado,
let's play it safe and start with this seatpost clamp first.
So, yeah, it fits perfectly.
There's even this little lip to keep it from going too far.
Starting to get tight.
A couple more cranky poos.
I'm actually surprised at how strong these threads are.
I'm really cranking down on this,
at least as hard as I would on an alloy seatpost.
(seatpost snaps)
(clicking tongue)
Well, this doesn't bode well for our more crucial parts,
but let's chalk it up to an engineering mistake.
I should have made that thicker.
Let's move on to these lock-on grips.
All right.
Not totally the same size as a real lock-on grip,
but the concept is the same.
It's basically just a grip body and then at the end,
there's a little clamp. Fits nice.
Let's tighten it down and see if it stops rotating.
(lock-on grip cracks)
(forced laughing, grunting)
This is not going well.
Well, I printed two of 'em.
Let me be a little more careful.
I'm gonna try some assembly compound.
I can't say I've ever used assembly compound
for lock-on grips, but it's plastic on carbon.
It makes sense that you would.
Assembly compound is just kind of this goop
with an abrasive in it, and so it sorta digs in
so you don't have to tighten things down as much.
I think we're almost there. Okay.
I just gave it a little turn.
Let's see if this is any harder to rotate.
I almost can't rotate that with my hand.
Ooh.
Starting to crack.
I can't turn that.
I'm squeezing as hard as I can,
and I could re-engineer this really easily
to not crack there just by being a little bit thicker.
I think we got our first win here.
Would've been nice to have two of 'em, one on each side,
but I think it's rideable.
But let's put some more 3D printed parts in this bike first.
What do you suppose the next sketchiest thing is?
Jockey wheel? (gentle upbeat music begins)
Not the same size, but it should work.
Jockey wheels are normally made of plastic.
I think it's gonna work fine.
I was even able to press
a nice little bearing into this thing and so,
I bet it's gonna be better than the original jockey wheel.
It's alive! She works! (bike wheels spokes clicking)
I would say maybe it's a little rough.
I don't see any reason why it wouldn't last
like for half a ride.
So two wins, one and a half wins?
Let's up the sketch factor a little bit.
I have this single speed gear
that we're gonna replace that cassette with.
(jazzy trumpets sounding)
(wrench ratcheting)
Whoa! Fits pretty nice! I almost got the width right.
I just need one little spacer. Nice!
All right, let's see if it works.
Oh my God! (wrench ratcheting)
It's so light. Okay.
Just a little bit of adjusting.
I mean, I don't think anybody's surprised
that it works here on the stand.
(bike wheels spokes clicking)
I'm wondering if we can pedal it around.
Let's give it a shot.
3D printed grip doesn't seem to do more
than just a handlebar.
I am pedaling.
I'm not gonna push it too hard, but I mean...
I had a little skip.
I don't know what that skipping is,
but I'm not gonna push my luck.
I think we need to put some more
3D printed parts in this bike.
All right.
Okay.
This looks insane! (laughing maniacally)
Fits right in there.
I bet this is gonna work better than a metal one.
(bike wheels spokes clicking)
Mm!
I think as long as we go easy on it, she's gonna work.
Easy does it with the pedaling.
It's my rear brake.
I'm gonna apply the rear brake. (brake squeaking)
Oh yeah, that stopped the bike.
I was going like a fraction of a mile per hour.
(brake squeaking)
(brake squeaking, snapping)
You know what? (chuckling)
That was a failure in my engineering.
I made these triangles (bike wheels spokes clicking)
with these stress points.
And after I printed it out,
I said, "You know what? It's probably gonna break there."
And it did.
It didn't break at the bolt holes or anything.
If I would've just made it one solid disc,
it would work better than an alloy rotor.
Definitely. Yeah. It was my stupid design.
Not the plastic.
All right. (sighing)
I wanna test something else,
but we gotta do it on my hard tail
because it's a Fox thru-axle. (upbeat music begins)
So as you can see, it's about like the axle I took out
except instead of an M6, it's an M8 at the end.
We need a little bitta help.
So I think it's gonna work great.
(upbeat music continues)
All right. I'm gonna play it safe
and just kinda roll down the lawn.
Ooh, I feel it, (bike brakes squealing)
like flexing for sure.
Ooh! (laughing, bike brakes squealing)
I thought I just heard it do a thing.
I'm trying to just stay off of it.
That's actually kind of scary.
There's a lotta play.
It fit's in tight and everything,
but it just, it's like mushy plastic.
I think that satisfies my curiosity.
Let's go hit the whale...
No, let's not hit the whale tail.
Uh, moving on.
Let's try the stem. (stem clicking)
I know what you're thinking.
I thought the same thing,
but this has so much more material in it.
I think it's actually gonna perform really well.
I'm not being sarcastic.
Let's install it and then be really, really careful.
From here, it feels like it's working.
So the consequences of a stem breaking,
or it's usually not the stem breaking,
it's usually the bolts.
I'm not worried about the bolts breaking.
I'm worried about them ripping out
of the plastic threads that they're screwed into.
And so, I'm gonna wear a full face helmet
and just take a little easy cruise down the trail
and probably lay off the back brake.
So the problem with this stem is that it feels perfect.
You push down on it, you steer, you do whatever.
It feels just like a normal stem.
It's not mushy.
It's not flexing.
That is really scary because I don't know at what point
this is not gonna feel like a normal stem.
So let's just do a little cruise.
(leaves rustling, bike brakes squealing)
Man, the stem feels okay.
No way I'm pedaling up this.
Oh! Oh yeah, I'm getting skipping.
All right.
Oh, man.
This stem scares me.
Can we make it over this log?
Okay. Just bump over this log nice and easy.
- Okay. (laughing)
Oh, Oh man.
I don't know if I care to really push this anymore but...
Ooh!
Whoa. (labored breathing)
Okay. (Velcro unsnapping)
We made it.
So it's fair to say that we learned something today,
or maybe we just confirmed what we all already knew.
3D printed plastic is not a good choice in material
for making durable bike parts.
But I think with a lotta these,
with a little re-engineering, they would work just fine.
Like the lock-on grip
has been performing great since the beginning.
The jockey wheel would probably be okay for a little bit.
I think there's a big market for 3D printed rotors,
(bike brakes squealing)
but I think the thing that I'm the most surprised about
is that the threads didn't get ripped out in any of these.
It was actually the part that broke.
And I think if we put enough plastic there,
it... don't ma... (sighing)
Don't make 3D printed bike parts.
(bike parts snapping)
- Ooh.
(bike brakes squealing, parts snapping)
- Anyway, I hope somebody learned something today.
And if not, I hope you at least found this entertaining.
And some of you might notice my new shirt.
It's Oscar and I going off the airbag jump
behind a big, full moon.
He's in the basket here, just like ET.
I'm stoked on it.
You can get this at (air whooshing)
cognitivemtb.com.
We have a brown version.
We have a hoodie.
Just in time for the holidays.
Thanks for riding with me today, and I'll see you next time.
And it did, it didn't break at the bolt holes or anything.
I think if I just made it a solid disc,
it would work better than a met... (cracking up)
(bike clicking)
- Whoa.