2: The dirt on the dropout

Hello. Good day to you from episode 2 of our new podcast series Project Breakaway, a metaphorical and literal time in the day when we here at Predator Cycling take some time away from working in the back of the shop to come and share with our listeners what we're doing, how we're doing it, what it takes to do it, our ideas, our innovative success stories, and even our missteps and failures. If you find yourself with an interest in bicycles, composite manufacturing, out of the box design, or even curiosities beyond, I encourage you to stick with us, settle in, and learn a little. I'm Courtney B, co-owner and project manager of Predator Cycling, and I'm here with my partner Aram Goganian, the co- other co-owner, CEO, lead designer and engineer, and I'll skip all the other accolades I gave you last last week in episode 1. No, I I I like that. You can you can do it again. No. No. Never. Just kidding. Maybe. Anyway, how's it going over there? It's going pretty well. Good. Um so Aram, I think in this episode, we really want to focus on one component section, a piece of the new RF 20 road frame that we mentioned last episode. Um so let's talk about the drive side dropout. Firstly, explain the drive side for us non-cyclists. Yeah, so um we say drive side that if you're sitting on the bike, that's the right side of the bike where the chain ring, the front derailleur, rear derailleur, chain, um cassettes and everything goes. So like the brain of the bicycle is on the right side. The the drive unit, the the what converts your power um your pedal power to forward mo- movement is is the drive side. That's My pedal power? Your pedal power is is unmatchable. Okay, so then let's explain what is the dropout and what is its function? So the dropout is what the rear wheel is held in place by. So it connects the chain stay, which is that tube that goes from the uh bottom bracket area where your pedals are, that's like kind of parallel to the ground to the back of the bike, that's the chain stay, and the seat stay is what goes from the dropout and goes up to your seat. So that kind of goes 45 degree angle going up to the seat. Mhm. Um and those the chain stay and the seat stay are connected at the dropout. I literally, I don't know if you remember, we used to have a picture of a bicycle Mhm. a frame and then each tube was actually the name of the tube. Uh-huh. That's how I learned how uh that's how I learned how a b- what a bicycle was and what each piece was before I started working here. Yeah, well we had to actually do that too for customers cuz a lot of customers didn't know what tubes were when we did like repairs or prototyping or custom work. So I think I'm going to try and throw that picture up just so people have a better understanding of what Yeah, for sure. each tube and each little It gets yeah doohickey on a bicycle is. For sure. It's helpful. Anyway, go ahead. Um so yeah, so one of the things that we we spent a lot of time um designing the dropout. Um cuz it's a complicated part cuz you have a lot of loads and forces. It's holding the rear wheel in place. It's holding the rear derailleur, which does the rear shifting. Um it's also where all the force from your pedaling is going into that dropout to turn that wheel. So there's there's a lot of leverage and forces and stuff that's happening, and it's in a tight spot. So there's a lot of um limitations on what you can do. So it's it's just a super complicated part. Right. So let's explain or discuss the historical materials that it uh drops out dropouts have usually been made out of specifically in the composite industry. In the composite world, there there's really I mean, in the last 5 or 6 years, there's only really been one way that most people make the dropout. Um and that's called a compression molded um process. There's there's a bulk mold, there's an SMC system. There's different styles, but the basic understanding is it's a compression mold. So um and it for everyone that doesn't know what compression molding is, um you're in composites, what we typically do is we take short strands of carbon fiber anywhere from 20 mil to 40 mil in length. Um and we have uh pre-preg, so it's already impregnated with epoxies, and we get that in a uh like a mat material, and then we cut that up and pack it into a mold. That's the net shape of the part very close to the net shape. It's kind of overbuilt a little bit in the key areas. And then we put it in about a 10 to 20 ton press, trying to get about anywhere from 200 to about 400 PSI uh mold pressure and compress that into a part. Um and that's typically how it's done. Okay. Um yeah, and then So let's discuss the RF 20's original dropout design and its evolution and how we've optimized it. Yeah, so like that's typically how the dropouts are made. And then so one of the things you have to do with that is once you get it out, you have to machine the the holes for where the axles go, where the where everything mounts, your internal geometries for your um your your tube connections that have to be all machined. Um so when we first designed the RF 20, um that was our intent. We were going to do it basically how everybody else did. Um and then we kind of went down that whole of like analyzing everything. We realized it's it's really not the best way to do it. Um there's a lot of extra material, and anytime you talk I mean, this is probably going down a rabbit hole here, but it anytime you talk about compression molding, it it's designed to be machined. That was why they designed it. Um originally, it was Callaway and Ferrari that did the original or Lamborghini. I think it's Lamborghini that originally did the first compression molded parts for for consumer stuff. Um and the whole concept was you could machine it. But once you cut it, you're talking about little hairs that are all connected to each other with epoxy systems that are pressurized. So as soon as you start cutting that away, um you actually cut the fibers. You're fraying it. You're fraying that part. A little weaker part. So yes, exactly. And and that matrix that holds it all together, all the the matrix and that those fibers that support each other um are randomly sorted in different ways, which gives it the ability to recover from that kind of cutting. Um so it's meant to be done like that, but you still weaken the part. Right. Um so we decided to work on a so one of the projects that we've been working on here is is net molding. Um and net molding is basically the concept that you get the finished part out of the mold. Like if you ever watch those How It's Made videos like injection molding where you see No, absolutely I've never seen those. Well, it's fun. You should look at it. Um it's really interesting. Injection molding, you basically like shoot plastic into a mold, and then like a essentially a finished part pops out. Um that's where we're taking it um with our system for the RF 20. Um so our dropout is made using a net molding system. So we don't have So there's no material excess. There's There's right. Possibly no weakening of frayed carbon fibers. Right. So Yes, exactly. You're 100%. So there's no cutting, there's there is on on the drive side dropout, there is no cutting on um a couple other components, there's very light trimming of a part because of flashing um that we have to trim it. But on the drive side dropout, there is no there is no machining done. So all of the strength and integrity of the fibers are completely kept. We also use up about 60% less material. So our material waste is less. Mhm. Um which because I like I said, I just kind of went down a rabbit hole. We also look at how much energy it takes to heat up the molds. Um so we could actually reduce how much energy we put into electricity we use to heat our molds. Um I am all about putting less energy into things. Yes. Well, I mean it costs money. I mean that that that it's money that spent. I am all about saving money here. For sure. So let's discuss the our dropout y- our shape is hollow inside. Our design is different. Mhm. Um So the the drive side dropout on the RF 20 is uh is fully hollow. Um it's also um we designed into it a cable management system so that you can run your derailleur cable for either if it's mechanical or electronic. Um there's a a a formed guide that goes through the back of the dropout and comes out the back. Mhm. So um yeah Is that something new to the industry or is that something It's been done. People have done similar systems where they have hollow top halves of the of the dropouts. Um people have tried to do it, and they've a couple companies have done a pretty good job of setting it up. Um one of the things that's different about this one is that it's the actual entire cavity of the guide is molded in the part. So there's no post like metal insert that goes in to kind of guide the cable in. Um there's no after like you know after the fact like glued in like a plastic insert or anything that guides it. It's actually molded into the frame, into the dropout. You're telling me, I'm the person who sits there and lays it up. You are. You are the person that does it. Um yeah. What else is fun and fancy about this dropout? Um the other thing that's really cool about this dropout is that it is both a mixture of um composite like uh SMC material, which is basically a chop material pre-preg chop material. Um but it's also directional fibers. So we actually are not just packing it with carbon, small strand carbon, and compression molding it. We're actually optimizing the fiber orientation for the loads and forces on the dropout. So this kind of gets really interesting cuz I think you've seen like over the last couple years um like titanium 3D printing has become real popular in bikes, and you can um the cool thing about it is about you using basically an SLS system. I would use a laser to to to melt um What's SLS? It's a it's a it's a type of printing that uses it's a powder based printing system where you have a powder and a laser that hits it and melts the titanium or uh aluminum. There's different types of powders you can. You can also use it with um um uh plastics. And they're printing titanium out of powder? Yeah, it's the powder itself is titanium. And then with the laser basically welds it essentially together. Um and it does it in layers. And it's very cool, and it the cool thing about it is you can actually very accurately um put material exactly where you need it. Um and something in composites and compression molding, you could never do. Um so we're kind of like splitting that area where you can actually put enough material where exactly where you need it in the direction you need it in all directions. So X, Y, Z, I mean a full orientation um into the part uh in the molding process. So it's kind of that um we use a lot of the topology optimization and um uh um and generative workflows that you use in the 3D printing realm, we use in designing our layup schedules for um composites, especially this dropout because it's very complicated. Um we actually did a a AU class on it. The the concept of the generative design. Oh yeah. Yeah, we did that. That was the first one we did together. Sounds familiar. Yeah, right. Um yeah, is there anything else that you'd like to discuss about the 3D print side of the technique and then how we manipulate it and maybe possibly creating an easier process, a more efficient process for us? Yeah, so one of the things that like I say we the the 3D printing revolution that's happened in the last uh what? 10 years? Yeah, 10, 15 years. It's just It's so crazy. 3D print has been out for so long and I know absolutely nothing about it. Um You know what they need? I don't know even you know like an Apple store when we were young and you'd go and play with your iPod Oh yeah. shuffle or whatever it was. Yeah. They need that for 3D print where you go in and you play with all the 3D printers. Oh, that'd be cool. Um well the 3D print, it's it's you know, the cool thing about 3D printing is is that it's a it's a I mean, it's been around for a while, but it's still a very new um area. So there's just new tech coming out at just such a rapid rate. It's really cool. And using it, I think using 3D print in manufacturing is it's it's there, Mhm. but it's not real it's not It's not as mainstream as it could be. It's not mainstream. When me as a normal layperson thinks about 3D print, I think of just like playing and making little tiny things in your house and like we made like a little toy boat for the bathtub or Yeah. the trend of 3D printing yourself Oh right. And your little statues, Uh-huh. Which my parents have done. Yeah, yeah, we have it But you don't think of it as an additive manufacturing type of force that could actually alleviate many problems. Right, but yes, you're absolutely right. And um 3D printing is getting really powerful in that sense, but the more another interesting aspect of it is is how it's affected uh our tools. So like some of our topology optimization, our uh T-spline modeling support, um a lot of things that we use in in 3D design have actually been accelerated because of 3D printing. Because we could now access we could make things that we couldn't make before. So that's kind of what's tying back into this process, and that's why I kind of draw a parallel between them and uh 3D printing 3D print manufacturing parts and our methodology we're using for these dropouts is that we're able to optimize fiber orientation in a net shaped part um in full 3D. So like we can manipulate which direction we need for like where we're having loads coming in on the part, we can manipulate in that direction. Okay, I need you know additional support here, so we're going to use a you know a uni directional fiber, we're going to use a you know a plane weave because we have an impact zone. We can really accurately um put material exactly where we need it, and then where we don't need it, we don't have to put it there. So that mentality of that net shaping of a part um we use a lot of processes that are processes that are that are um used in 3D print. So the 3D print is not just for the part itself. I don't want to confuse it with like oh there's a 3D print inside this part. It's Oh, no, no. It's utilized also as a mold making Yeah, we make a lot of I mean, we here in the shop, we use a lot of 3D print for tools. We make a lot of tools um are made from 3D prints or um or molds of tools are made in 3D prints. Yeah, we use a lot of 3D printing. And Aram's always talking about the material science is a 3D print. It's not just plastic. They're doing like carbon fiber infused prints and Yeah, there's there's some cool stuff. There's I it I it yeah, a bunch of my newsfeeds in the morning, I'm like wait, they're doing what with what? Like I it blows my mind what they're doing. Um yeah, so you can use like um carbon fiber infused like uh pack and stuff you can use, which is uh primarily for aerospace cuz of just the price points. But you can do that. Um they're even doing But this is available. Oh, yeah. You can just Oh, yeah. Just go on Amazon and buy this. Uh-huh. Right. I just want people to think when you hear aerospace, people are like oh, that's an industry that's untouchable and no one else can play with these materials. Oh, no. It's totally available. The only problem you get into some of those materials is you get into like some super high temp stuff. Mhm. And as you get into higher temperatures, you start getting into more complicated because you have um um you have warping. You also have shrinking factors, and then just the equipment that it takes to get to that temperature and hold a tolerance and for an extended period of time on a 3D printer, it just gets really hard. Um I mean, that's something that we've been playing with. I know we I think we hinted about it in the last podcast, but we've been doing some high temperature printing here. Right. Um and we've been doing quite a bit of 3D I mean, we've we've invested a lot of time and money and energy into 3D print. Primarily up until now, it's been entirely made for um um uh tools, that's what we've used it for. Um but hopefully that may change. The carbon fiber, yeah, I wanted to discuss maybe a future podcast here coming up um where we dis- we're going to design discuss the design and simulation um and you but we're also going to be talking about 3D print here coming up and our evolution into it. But also um I think coming up sooner than later, we're going to talk about design simulation and CFD, which is computational fluid dynamics for people like me. Uh that just means a wind tunnel with colorful lines that flow over a bicycle. Yeah. Um yeah, we do a lot of simulation here. So a big a big part of our uh workflow here is simulation and using that as an input really early on in the design phase so that we can get feedback instantaneously on what we should be doing and where we should be going in the direction of the bike. Right. And the RF 20 spent a obscene amount of time in simulation for both mechanical and for CFD. Yes. So we're going to delve into that next week, I believe. Yeah. So um yeah, so let's quick before we head out um talk about some recent news here at the shop. Um let's discuss LinkedIn. Yeah, so um during this whole uh COVID times, we actually uh I did my first LinkedIn course. LinkedIn Learning. LinkedIn Learning. So Which was lynda.com for people who don't know and to people who don't know what lynda.com was, it's kind of like um online classes you pay for to learn new skills and hobbies. Yeah. I actually I used to use it all the time because I I learned uh my uh some of my Photoshop, Premiere skills, and Adobe skills I learned from there and some of I learned my Photoshop skills from a book called Photoshop for Dummies. I And I thought I knew why. I literally had that book. Oh. Do you remember that series? Oh, yeah. I have I have I had one. I wonder if they still exist. Anyway. Uh but yeah, so they approached us after a LinkedIn uh after an AU class that we taught, and were interested in us teaching a class. So we did. We taught a class um and you know, somehow I did the class on uh designing a bicycle. Go figure. So there's one that's on there right now. Um maybe we'll put the link in the um in the blog post. Section. Uh but yeah, so there's a class there, and we're in the works right now of doing a really cool class that's talking about um the concept of uh designing uh consumer part to be made out of carbon fiber. So we're talking about the workflow from um how carbon fiber works and the material properties. Very basic understanding is an intro class. Yeah, an intro into composites like kind of intro 101 to composites but geared towards design and then a just design to all the way through manufacture workflow. Great. So, it should be fun. Yeah, and hopefully more future LinkedIn learning classes. Yeah, we got another one lined up after that one too already. So, Yeah. Um, it should be fun. It's it's been nice and I I used a lot of those online learning tools for all kinds of software and plugins and whatnot so it's kind of nice to If there is anything that this guy likes, well, I don't know. It it could be a toss up between uh conferences and expos I mean luckily this year because of COVID we had we haven't had to go to an expo or conference. And online learning videos. You you learn so many interesting things. There's so many interesting things out there. You yes, I'm sure there are. I just don't have the brain power I guess I don't have the brain power to sit down in front of a screen for that long. Oh you do. You could do it. Oh well, I guess I do but to watch mindless TV, not to learn actual things that can help me in life. Uh, no, you enjoy it. Anyway, okay, let's wrap this up. We thank you for choosing to take some time with us and we look forward to future breakaways. I will try my hardest to put any mentions in our new section on predatorcycling.com which I obviously failed out last week in episode. So hopefully I can get that conference call background screenshot with mentioned last week up too. Also, look for us on Instagram and LinkedIn, Facebook, Twitter, and Parler. Just getting that last one was just a joke. It was a joke. Um, let's get to work. Please share, like, and subscribe. Apple podcasts are up and I believe Google podcasts are pending. Anyway, thanks for listening. Have a good one and find some time to break away.