Craig Calfee Part 2: Gravel Industry Pioneer

In this part two of our conversation with bike industry pioneer Craig Calfee, he and Randall do a deep dive into the merits of suspension on gravel and road bikes before jumping into e-bike conversions, variable head angles, regenerative braking, an E-motorcycle project Craig is involved with in Africa, ideas for the ultimate mass-produced frame, and the challenges and opportunities of localized assembly and production. Calfee Designs Website

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Craig Calfee Part 2

[00:00:00] Randal R. Jacobs: Welcome to the gravel ride podcast. I'm your host Randall Jacobs. And today I, once again have my friend Craig Calfee, this is part two of our conversation. We'll be having a part three at some point where we get into wood and bamboo bikes, but today we're going to be focusing on mostly on carbon fiber.

And so with that first topic where we left off in the last conversation, Craig was, we were getting into suspension, particularly suspension on road bikes, but that would also apply to gravel bikes too.

[00:00:28] Craig Calfee: Yeah, that's a great topic. It's one really close to my heart because we kind of stumbled on it through the bamboo bikes actually. And it was about the vibration damping of. We had a triathlete who had a really nice carbon fiber race bike that he used for Ironman distance triathlon. He's also a data junkie.

So he had all the, all the, you know, biofeedback stuff, the heart rate monitor, the lactose levels, all kinds of crazy stuff that he measures on his training rides. So he also ordered a bamboo training bike just for fun. Really. He's a wealthy guy who can afford multiple expensive bikes. And we built at exactly the same geometry as his race bike, and the only difference ended up really being the race wheels that he didn't use all the time.

Anyway. So he was doing his training runs and found that he was actually faster on the bamboo bike, which was about two pounds heavier than his race bike. So. I asked him, well, let me guess you're feeling fresher towards the end of the, the bike segment and your time advantages in the latter half of that segment, he said, you're right.

And why is that? And I said, well, the only clue I have is that the bamboo definitely absorbs vibration better. So you're subjecting your body to less fatiguing vibration. And he said, that's exactly how it feels and has run after the bike is, is generally faster as well. And that backs up what Dave Scott reported when he rode our bike in the Ironman, when it came out of retirement at the age of 40 and came in second to, um, to Greg Welch at the iron man everyone thought Dave was going to be top 20 maybe, but he ended up second place.

And he credited that performance to feeling super comfortable on his Tetra custom tri bike that we built for him, which is notoriously smooth riding because of their skinny seat stays. Anyway. Um, so the vibration damping also has been studied by insurance companies for truck drivers and airline pilots.

So they do these tests to figure out how fatigued people are based on how much vibration they're subject to, and they've shown you know, hands down that it's, that vibration causes fatigue. And there's some scientific details on that that I could get into, but it's, um, probably better to move on here.

So we found that, um, aside from the, the fatigue we've found that it had better traction and that allowed for more efficient client. So for a racing cycling. Yes. Fatigue is important, but actually having better traction for getting a better time on climbing is really where the rubber meets the road, literally.

Yeah,

but for me that the biggest one was layers less know you're going to crash out of the tour de France less often. So being able to corner faster and do faster descents without crashing is as important, if not more important than having more efficiency climbing so that, you know, those three factors less fatigue, better traction, and more stable at high speed are to me the most important they're all three of them make for a faster bike.

And we.

[00:04:10] Randal R. Jacobs: Oh, go ahead. Um, well I was going to say like on the flats and on the dissents, it's pretty obvious. And I've actually been thinking a lot about this. You know, our listeners will know that I'm a big proponent of high volume tubeless tires on wide rims, right. Run at lower pressures for bigger contact patch.

And I'm coming around to this idea that while that is good, that's that suspension that pneumatic suspension also results in varying tracks.

[00:04:38] Craig Calfee: Yeah.

[00:04:39] Randal R. Jacobs: yeah.

[00:04:40] Craig Calfee: So we, we actually measured that, um, most people are like, well, you're going to lose something on the climb. You know, you're going to activate the suspension and lose a percentage of your input, activating suspension. And we thought, okay, you know, there is some of that, but it seems like that's minimal compared to the advantage in climbing.

So we understand about the pneumatic suspension and part of it was to go back to the advantage of less rolling resistance. With a smaller tire, higher pressure you know, tires. And so we did an experiment where with a couple of interns from Germany that were really into the data collection side, and we set up a manta with an electric motor on it an e-bike effectively.

So we could do a climb and measure the power required to get from the bottom to the top. And we found that w w we did 20 runs. So 10, 10 runs without the suspension and 10 with the suspension, meaning we would put an aluminum slug in where a spring used to be. And that would be the, the locked out version.

And all of the runs with the suspension were about 2% of fat, you know, further up the test run than the ones that were locked out, which was kind of surprising. We w the consistency of it was amazing actually. So we found that, you know, he got up the hill with the same amount of energy further up the hill.

So that was, um, you know, a graphic representation of how much more efficient it was. And then we wanted to subtract the loss of the, the losses from pedal induced suspension activation. And so we put up, put a a power meter on the crank sexually. That was the, um, the, the what's the really well known power crank meter the name escapes me, but anyway, we put a hub mounted power meter and a crank mounted power meter on the same bike.

And we were able to measure the difference between the two and it ended up being about 1%. So we did have a situation where it was more efficient climbing, about 2%. Minus 1% loss of a pedal induced suspension activation. And so net gain of 1%, and that was noticeable by, by riders. They could feel that 1% but that actually matters more in a race where, you know, you actually win by significant amount expending the same amount of energy.

So that, that was really the, the revelation that caused me to predict that at some point every bike in the tour de France will have suspension with at least 12 millimeters of travel.

[00:07:27] Randal R. Jacobs: I've been just to repeat, like, I've been a big proponent of non suspended bikes. I actually, we Craig and I just you know, kind of tongue in cheek offered our, our bikes of the year, gravel bikes of the year. And the one that I nominated was an old one, the the open up, because it is not going with some of these new fangled you know, attempts to suspension and so on.

And I still I still see a place for that, but. As I'm thinking about like a hypothesis as to why you're getting those improvements in efficiency, even on a climb. The thing that comes to mind is a unsprung mass in the amount of VR. You know, you take those the front and the rear axle, and you look at their path through space.

And when you have an active suspension when you have a suspension that is built into say the seat stays or the fork, or what have you, as opposed to the, you know, using the tire, you're going to probably get less vertical deflection as the bike is traveling over the road. And even a smooth road is going to have, you know, meaningful amounts of bumps that are going to result in you know, energy losses as the, not just the bike, the unsprung mass of the bike, but the unsprung mass of the body of the rider on the bike as those are moving up and down is that what you suspect as well?

Or do you have any data on, like, what is the actual.

[00:08:45] Craig Calfee: Yeah, that is the mechanism that's been studied a fair amount, um, and regular suspension in detail was motorcycle. um, the, the so it's already been proven that suspension is faster because you're not raising and lowering the mass of the bike and rider over these minute bumps, which if you add up all of the miniature bumps that you're getting up and over on a race it's like an additional, you know, 20 feet of, of elevation that you have to climb relative to another bike that has that, that the suspension only has a fraction of the weight going up and over the bump, but your body and the rest of the, of the bike is not needing to be lifted up and over.

So that's that's physics 1 0 1 and. Whether you do that with new Maddix or with a steel spring it doesn't matter as much, except that you can gain back the rolling resistance losses that you're getting from the history of rubber, as it has to bend and flex up and over that bump steel Springs are way more efficient than rubber as a spring.

[00:09:59] Randal R. Jacobs: The rotational inertia as Well, Those, all those little Micheal micro accelerations that you have with a higher volume tire that is inherently higher mass to a, is that a significant factor as

[00:10:12] Craig Calfee: I haven't measured that myself, but, um, I mean, it seems to me that would be an issue. Everyone talks about you know, the rotating weight. So, you know, why are people spending so much money on carbon fiber rims? You know, be nice to have, you know, for sprinting and accelerating. It certainly feels that.

[00:10:31] Randal R. Jacobs: Hmm, when it occurs to me too. So last time we spoke about, you know, one bikes or at least I use this term to describe the bike that you had come out with. The, I think he called it the adventure, which I described as, you know, the first, the first true one bike. Cause it was an endurance road type geometry, but with clearance for big six 50 B tires is very much my philosophy.

There's been this trend in the industry towards gravel bikes, having higher volume, 700 C, um, and people feeling or believing that it's faster. And that makes sense. From the perspective, that was a part of the marketing of 29 or wheels where the attack angle would be less. And so that vertical deflection is happening over a longer distance and a longer amount of time. Um, but you know, with, with an active suspension, you no longer have to, you, you can get that benefit of reducing the vertical deflection and the losses associated with little bumps in the road. Um, without having to go with that bigger tire, which means you can still maintain an endurance road geometry, or even a proper road bike geometry on a bike, that'll pay take big six 50 BS.

So that keeps us back in one bite territory, which I like as well.

[00:11:37] Craig Calfee: Yep. Absolutely. That's that's a really good argument for slightly smaller wheels.

[00:11:44] Randal R. Jacobs: Yeah. Would you, so you're doing this with a spring any damping in that system?

[00:11:50] Craig Calfee: Well, the carbon fiber stays are kind of self damping. We do too. We basically have a hybrid spring. The carbon chain stays and the steel spring up at the seat up above the brake brake brake bridge. Um, that's so we're getting both and the carbon stays, tend to absorb a lot of the, the resonance of the steel.

do have, um, a rubber bottom out a plug, but that's about as much damping as we get. And by the way, we found that elastomers make a pretty bad spring for, for bicycles. And I know that's been been proven years and years ago on the earliest mountain bike suspensions, but a lot of the bike companies are coming up with these rode bikes that have rubber bits in them that try to simulate some level of suspension.

But if you ever ride one of those and you hit a pretty rough bump, the rubber stiffens up, and it actually becomes useless on the, where counts the most, the, you know, the more the heavier hits it's it's we measured that. And it was definitely not as good as the steel.

[00:13:02] Randal R. Jacobs: And this is true even of like more advanced, a less Americ materials that have come out since the battle days of, you know, 40 millimeter mountain bike forks with.

[00:13:11] Craig Calfee: Yeah, there hasn't been a ton of improvement on that. There's been different viscosities used, but, um, the problem is the molecules can't get out of their own way. Fast enough, you know, that's, that's what it boils down to.

[00:13:26] Randal R. Jacobs: Well, and then there's the issue of temperature sensitivity to which I believe that there's been some improvement made in that, you know, better than I would.

[00:13:33] Craig Calfee: That's probably the one area of improvement. Yup.

[00:13:36] Randal R. Jacobs: Yeah. So just for the audience in cold temperatures, these materials tend to become firmer in hot temperatures. They tend to be more compliance. And so you don't have consistency across temperature ranges, even though your body is, is not changing the terrain isn't changing. So that's another problem with the last tumors as a suspension of. Um, and then there's the issue of certain companies who will remain nameless having technologies where they started off by putting in an elastomer somewhere in, in the the chain, the suspension chain of the frame itself. And then ultimately, because it was all marketing anyways, they just bolted things on and actually compromise the frame in doing so. Yeah. Um, they, they rhymed with a certain minty candy called certs that anyways, we'll, we'll continue on there, but a lot of, a lot of that sort of marketing fortunately I don't know what your opinion is on that one. Do you see more or less of that sort of a marketing who he, these days.

[00:14:32] Craig Calfee: Well, that's been going on since day one. I mean, that's, that's, you know, that's part of the business and, you know, it's as much about fashion as it is about technology. So the marketing guys are needing to sell what's popular. You know, suspension starts getting talked about as a possibly good thing, then they're going to, you know, try every trick in the book to, to hype it up by doing actual measurements.

And studies is really fun because you can actually see serious gains in in the efficiency of the bike and for races like the tour de France, where three weeks of racing, you know, 1% means you win. You know, it's interesting. I don't brag too much about building bikes for Greg , Greg Lamond, but you know, at one point he was looking at our gussets and thinking, you know, you should really trim those gussets down just a little bit smaller because they're less aerodynamic.

And this is the biggest it's at the bottom bracket, which were set kind of sideways to the wind. And I've felt like arguing with him a little bit about, you know, this really not much, it's just, you know, this tiniest little bit, but here's a guy who won the tour by eight seconds. How do you argue with that guy?

Oh no. So 1% is huge in that route.

[00:15:57] Randal R. Jacobs: Yeah, Yeah. Yeah.

Um, Hmm. And so you're, you did, um, 12 millimeters of suspension in the rear of the manta. And how did you come up with that number? Is that what you consider the optimum for road and what would you do for gravel?

[00:16:13] Craig Calfee: I think it's actually quite good for both. He couldn't go even more for gravel depending on just how rough the terrain is, but your legs end up doing more suspension, work on much rougher terrain than that. On a really efficient, if you want your, to have much less peddling losses. I think that's where the there's a transition at some point you have to minimize the travel to minimize the peddling law.

So we found that 12 millimeters with, and there's three spring rates that we like to play with depending on the weight of the rider. So the, the stiffest one with a heavier rider it basically maxes out at 12 millimeters under the most extreme scenarios. Um, the, the, the problem really is matching this front suspension to rear suspension.

And there's currently no decent front suspension road forks, or even a road stem that that is available. We did a bunch of testing with, with Ben jock, Maine, where he was trying to, he loved the suspension. He loved the concept. He felt like it was faster, but at the end he was like, you know, I really need the front to match the.

So he can just forget about the bike as he's putting in an all out effort. So he's the front wheel behaves differently if it's not suspended, then the rear wheel, and as you're racing hard you have to constantly consider that the front has less ability to track than the rear. In other words, it's, you really need the front as much as you need the rear, particularly for the high-speed descending and, and trying to crash less often.

That's that's more on the front wheel than the rear. So, we re we tried a couple of experiments with suspension forks. It became really difficult to, to build one. No, it's just a really hard challenge to build a lightweight carbon for that also has 12 millimeters of travel. We just haven't been able to do it.

[00:18:17] Randal R. Jacobs: What's a much more complex structural challenge. You have much higher stresses. The consequences of failure are that much higher. You probably not need a lot more complexity in the design, a lot more mass being added versus, you know, adding something to a mano seat's day.

[00:18:32] Craig Calfee: That's right. It's much more difficult. And yeah, the, I, I broke my first bone in my body testing that for just a, the little finger on my, on my, on my right hand. But, you know, I, I was trying to break it and I usually fall, you know, I do, I do my own stunts and I, I used to be able to fall really well, but that one, right.

I had, when I fell, I had to, I put my hand out just by mistake, but I literally broke the fork on a speed bump. I stiff arm to speed bump, and I was able to crack the fork and have it fail. And it was it, it kind of set us back, um, because of the. Lack of popularity right now with suspension on forks for road bikes.

It's just too difficult in the current market, but there are some suspension stems out there now that are really interesting. And we've been messing around with that. And that's pretty good. That's really close to ideal, but, um, I don't think it's gonna going to be adopted a hundred percent unless someone does some tests with a stem and the rear and shows that it's absolutely the best thing since sliced bread.

So we need more, more testing and more pro level riders who, who can vouch for.

[00:19:47] Randal R. Jacobs: Hmm. When I got something that I've been working on that I'm okay. Sharing in a public forum. So I I've talked about mullet setups and going with a higher volume fronts than the rear because you have less mass over the front tire when climbing or on a flat. And so the rolling resistance impact is generally lower than if you had that same volume tire in the back.

And so that could be one way to give a little bit more compliance at a suspension step. As

[00:20:13] Craig Calfee: W does sure. Just the UCI allow, um, different wheel sizes and gravel racing. Is, is there any, I don't know enough about it, but I know in red rain they insist upon the same size wheels,

[00:20:27] Randal R. Jacobs: I don't know. I've never heard this come up. I don't know that there are there UCI gravel races at this point.

[00:20:34] Craig Calfee: you know?

[00:20:35] Randal R. Jacobs: so out of the loop, when it comes to elite racing, I couldn't care less. I care much more about, you know, people were just out to have a good time.

[00:20:42] Craig Calfee: Yeah. So for our purposes on the, you know, sticking with the road bike suspension thing, um, yeah, you can't do that because of UCI rules. So

[00:20:52] Randal R. Jacobs: interesting. I thought that, um, I thought that for a time, like the specialized had their TT bikes running a narrower tire up front and a wider one in the rear aerodynamics.

[00:21:04] Craig Calfee: sizes, for sure, but not, not wool diameters,

[00:21:07] Randal R. Jacobs: Oh, I see. Yeah, I'm talking same rim, same rim. size, actually the same exact rims, but say in a, um, in a more cross-country oriented gravel setup, running a, you know, a 2.25 in the front in a 2.0, you know, semi slicker file trade in the rear, and then having the rear with that 10 or 12 mil of suspension that you described in upfront combining that higher volume, lower pressure tire with a suspension stem.

The one that we talk about a lot is the one from Redshift. I don't know if you have others that you recommend as well. And then I have a, a concept for a handlebar that I'm going to run by you at some point that would have some adjustable suspension component built into that as well.

[00:21:47] Craig Calfee: Yeah. Yeah. I think that could work. I mean, that would be worth trying and doing some tests on. Um, and we do like the suspension stems. We, we put a steel spring and one of the redshifts stems a couple of years ago and it, it actually was a significant improvement because it took out the, the elastomer junk they have in there.

And it really helped on the heavier hits. But the Redshift stem is compared to a stiff stem is great, but the Cirrus stem with the body float Cirrus cycles stem with steel Springs is really my favorite. It's a little clunky looking, but it's not as aesthetically pleasing to look at, but, um, it performs really.

[00:22:35] Randal R. Jacobs: And that's a linkage stem, right? A more complex linkage stem versus a single pivot. Like the red shift.

[00:22:40] Craig Calfee: Yeah. Yeah. And it keeps your, your handlebars at the same orientation where the Redshift causes the bars to tilt down when it, when it activates.

[00:22:50] Randal R. Jacobs: Yeah, you have to, you have to account for that in the bar rotation in the most outright position.

[00:22:55] Craig Calfee: it'd be nice to avoid that. So, back to the fork, you know, that the fork is really the place to do it. And the Lao forks are really kind of like their concept, but if they could do a road version, that would be really great.

[00:23:10] Randal R. Jacobs: The challenge I see with love, I see kind of two primary challenges. One is damping, right? Cause it kind of is what it is. And I could imagine a design where you actually put elastomers between those leaps that, in that fork. And so when, you know, when it is compressing, it's actually compressing that elastomer and that, you know, it's not, it's not really adjusted.

Well, I guess you could swap different, you know, different numbers of elastomers or different durometers of elastomers in there to adjust that. But then the other thing. To my understanding is the bigger issue is like we'll flop like lateral flop because you don't have a telescoping section like you do, um, say on a traditional mountain bike suspension forks.

So the tire at a hard angle in a corner can actually deflect to one side or the other materially in a way that can be unsettling. I don't know how much experience you have with those forks. I, I haven't written them myself to any significant extent.

[00:24:05] Craig Calfee: Yeah, they're not, they're not perfect for road bikes. Certainly. They're they're okay. They, and they do need damping on their higher travel forks, but the, the fork that I built, um, I noticed that the vibrate, the. Um, damping, wasn't really an important issue. Such a little small amount of travel. It, it didn't oscillate at all.

It just, you know, gave, it, gave it to you right when you needed it and didn't oscillate or BA or Bob at all. So for me, that short amount of travel doesn't really require damping. Um, it might be a nice thing to tune as you, as this whole idea evolves, but, um, initially I don't think it's something that should prevent it from happening.

[00:24:52] Randal R. Jacobs: Well, at some point I have a, a, an idea for a real time adjustable suspension built into the layup of the frame that run by you. And we can see if that's an experiment. We might run at some point, but I'm pretty sold on this concept. My big concerns would be weight and complexity, which in turn adds costs.

But from a, you know, what does the future look like? We have the technology, it seems like an it's an engineering problem, not a, a an issue of proving the physics at this point, from what you've described.

[00:25:20] Craig Calfee: Yeah. Yeah. It's a marketing problem too, though. So it's, I think the way I wanted to approach it was to get a pro racer on it who could see that it was definitely faster. And then they go back to the team and say, look, we need suspension because we'll win. And the team generally pushes for that. And if a large bike sponsor wants to win, then they'll develop the suspension.

So until that happens, it's going to be an uphill battle for, for us smaller guys.

[00:25:56] Randal R. Jacobs: Well, let's have a sidebar conversation after this about whether that can be made economic in the, in the near term. All right. So everybody you've heard it. I am now sold on the idea of, bikes as well. So more on this topic as we go, but Bravo Craig, it's taken, it's taken a while to get me convinced, but I'm definitely in your camp now.

All right. So next step other fun things to talk about that you've been involved in. So in 2019 you started doing a retrofit, like, e-bike system retrofits. So you want to talk about that program.

[00:26:27] Craig Calfee: Yeah, that's been really fun to see all the bikes coming through that that have been hanging on people's in people's garages, a great high-quality bike often from, you know, 10 to even 20 years ago. Like a good titanium bike that just, you know, never corroded. And they moved on to a nicer carbon bike or something and, but these beautiful bikes are still, you know, there and people want to ride them.

So it's a perfect opportunity to electrify some of them to try out you know, what, what an electric assist will do for you. For those of us you know, a little bit older, um, it's nice to ride with you young punks and keep up, you know, and you know, still have fun as a group. I mean, we still have the bike handling skills, but maybe we can't get up the hill as fast as you, but we can certainly, you know, hold our line, coming down the hill and being able to do it without being utterly exhausted is, is really helpful in a lot of.

[00:27:29] Randal R. Jacobs: And what are the e-bike systems that you're using? Are these kind of.

off the shelf or is it a you're you're buying separate components and integrating them in some special ways or any software involved at the level that you're implementing?

[00:27:41] Craig Calfee: Yeah, we're, we're doing a grin kit. It's basically a hub motor, fairly small hub motors, unless you're on tandems. We use a bigger one and we try to really simplify the user interface. So it's, it just feels more like a bike than an e-bike. So we have a little circuit board that we programmed for the lights that are just little led lights that go into your handlebar tape or on your, on your bars.

And it just shows how much batteries left and how much of an assist level you have. So it's really super simple. We basically over oversimplified it to make it. As much like a bike ride as, and not an e-bike, so it's more bike than e-bike.

[00:28:29] Randal R. Jacobs: And you're doing, um, not just Calfee bikes, but any bike that somebody would want to retrofit

[00:28:34] Craig Calfee: Yeah, yeah.

[00:28:35] Randal R. Jacobs: way for you to make that work.

[00:28:36] Craig Calfee: That's right. So we were able to do pretty much anything at this point. And it's been really fun seeing these older bikes come through and, and having them get written again now, and they end up, some of them may end up becoming their favorite bike and they sell the newer bike and, and they're back on their older, older, trustworthy bike that they've spent so much time on and, you know, keep keeping bikes from getting sold and used for cheap and keeping them out of the landfill.

[00:29:06] Randal R. Jacobs: It'd be interesting to see if we see more e-bikes in the ridership. We see quite a few folks. Who've posted pictures of the know 20, 30 year old Bridgestone 26 inch mountain bikes that have been converted to gravel bikes for winter duty here in the Northeast. So definitely seeing new life and bikes that were good in their time and still have a lot of life in them.

[00:29:26] Craig Calfee: Yeah. Yeah. That's that's, I love to see that, you know, so many great bikes that are kind of old and forgotten and get a lot of dust on them. And then they get brought out. I mean, it's similar to our carbon repair business, you know, just, no, you don't have to throw it away. Let's let's repair that. And some of our carbon repair customers are sending their repaired bikes to be converted to e-bikes.

Cause it's not the latest greatest, and it's, it had been crashed and we repaired it and, and it's sort of the second bike, you know, they've already bought a nice new. But they kept the old bike. And now, now it's got an electric hub motor on it. So it's, it's great.

[00:30:07] Randal R. Jacobs: That makes a ton of sense. Do you ever, um, do you ever integrate the batteries into one of those broken carbon frames, like to get into the down two or is it usually an external Mount.

[00:30:16] Craig Calfee: It's, it's external Mount. I mean, it's, it doesn't really help to try to integrate it. Um, you know, you pretty much have to design the bike from, from the beginning to be an e-bike, if you want to do that. And that's what all the new e-bikes are or most of them, but we use a carbon fiber bag that Velcros to the top to basically it looks nice.

It's, it's very useful bag that you can carry as little or as many batteries as you want. We use the little a hundred watt hour LIGO batteries, so you can choose to bring a smaller amount of battery or bring all of them and you can travel on an airplane with them as well. So it's become a default for the touring by.

Particularly the coupler bikes, you know, SNS, couplers, bikes, or traveling, you know, bring the AR kit with the Lego batteries and you can have an eBike in, in Europe or south America, wherever you're going. You can bring your eBikes stuff with you.

[00:31:11] Randal R. Jacobs: On in turn, if you're running a smaller power pack, you're probably running a lower output motor keeping the whole system lighter and more efficient. And you know, it's, it's not, it's not a moped it's you plus a, which is a philosophy that I think, um, makes a tremendous amount of sense for enthusiast oriented bikes, where you want to maintain the handling characteristics and so on.

And you want to maintain the range without ending up with a, a 40, 50 pound behemoth.

[00:31:36] Craig Calfee: That's right. That's a big, that's a big deal for a lot of our customers.

[00:31:40] Randal R. Jacobs: Yeah. So then that brings us up to last year and you came out with your assesful hard tail. When you tell us about this.

[00:31:46] Craig Calfee: Yeah. The circles also have really exciting project because we're able to. Um, address the questions that are popping up, you know, over the past couple of years around head tube angle, and what's the best head tube angle for a given type of ride. And the other issue that it solves is, um, all these different categories of bike, you know, Enduro by cross-country bike, even a gravel bike, it's sort of, you know, all these niches of utilities, which imply that you need six bikes to, to have, you know, the right bike for all conditions.

You know, where, you know, I'm kind of more minimalist. I like to have the N minus one concept where this is a bike that, that does pretty much everything kind of like your one bike concept. So it, it has an adjustable head tube angle using flip plates, and we're able to adjust the head angle enough so that you can swap out different fork travels.

So we're able to go up to with like a one 60 travel for. On this hard tail and you can also do a one 20 travel or 100 millimeter travel by changing the head tube angle. We have an eccentric bottom bracket, so you can raise and lower your bottom bracket all with an Allen wrench on the trail if you want.

So it's, it's really fun to climb a good, good solid climb with a head angle. That's a bit steeper mix of very efficient pedaling feels great. And then at the top of the climb, you whip out your Allen wrench, flipped the head, the flip plates around, and now do the descent with a two degree slacker head angle.

That's a really big difference and it's super fun, you know, to do that right on.

[00:33:37] Randal R. Jacobs: Well, I think for, I mean, I maybe simply because I haven't tried it yet for gravel bikes, I think. The future is also this, you know, adjustable geometry, again, keeping the ones, the one by concept of having a bike that has the snappy you know, performance road, geometry on one end of the spectrum. But then, you know, you get a more upright position.

That's a little bit more slacked out, but slower steering for your, you know, borderline cross-country setup when you're running a, you know, as I was saying, like a two to five or even a two, four upfront and like a 2.0 or a two to five in the back. So I do, I do think adjustable suspension is something that we're seeing in the gravel space, quite a bit with bikes, like the the allied.

Was it the allied able, no, the allied echo. I'm curious, what is the percentage change in head tube and axle and the amount of axle the crown change? Because obviously those are changing in tandem depending on the forks. So maybe we keep the fork constant, you know, you have a one 40 millimeter fork on that bike on a size, medium, or a size large.

How much does the head tube angle changing without changing the axle? The crown.

[00:34:41] Craig Calfee: Well, as much as you want, I mean, you can bring our flip plates go from plus zero, zero plus four and zero to minus four. So it's an eight degree range.

[00:34:53] Randal R. Jacobs: Oh, wow. Okay.

[00:34:54] Craig Calfee: Which is ridiculous, you know, but when you change the fork travel, when you do change that actual crown things change radically. So you're compensating for the tilting of the bike forward as you go to a shorter travel for.

So you wouldn't normally change your head angle by eight degrees. Two is plenty, you know,

[00:35:14] Randal R. Jacobs: Yeah.

[00:35:14] Craig Calfee: you have the option, you know, with that, to, to do it as much as you want.

[00:35:19] Randal R. Jacobs: And the, I remember that Fox had their talus fork at one point where you could change the travel on the flight. Is there anything that's well implemented out there right now? Or is it all throwing a new spacer in

[00:35:30] Craig Calfee: I need that. Yeah. I haven't, I haven't looked into that. I, I haven't seen changing of actual travel on the fly, but you know, all I'm really seeing is lockout mechanisms.

[00:35:41] Randal R. Jacobs: So then let's get into some, some fun side topics. So, I've been to your workshop a few times at this point. Um, and I've described it as what a 10 year old bike nerd would, would create if they had like all the resources to, to do whatever they want in terms of fun projects and so on. And some of the things that I recall seeing in your workshop, one was a a, um, somewhat stripped down zero electric motorcycle.

I remember an electric little race cart of some sort. So when you share some of the, the weird wild and wonderful projects that you've had going on in that workshop of yours, maybe describe the workshop itself.

[00:36:18] Craig Calfee: Yeah, we have a pretty big shop that, um, that we basically pay under market rates for that, which is why we can afford to have a bigger shop it's on a school campus. And part of the deal is we're supposed to provide a on the job training or job experience to some of the students at the school. So, which is easy to do.

And they don't, you know, send us a ton of kids. We have to chase after it's usually one or maybe two at a time, and we keep them busy with all kinds of stuff, but the projects, um, we're allowed to basically spread out and have projects going that can go at their own pace. And some of the projects go at a very fast pace, especially when there's real money involved and some take longer to develop.

So for example, the zero motorcycle stuff has been, has been very diverse in that we're dealing with SWAT changing the batteries out for a zero, had us do a battery upgrade project for a fleet of motorcycles. So we did that for them. We did another. Project where we changed the change the motor out of the whole model year of bikes went on 2012.

They had to upgrade their motors. So we came up with a Mo a different way to Mount a new motor in the old bike. And now we're involved with an aerodynamic body kit for the bikes. This is kind of a speculative project where we're making carbon fiber bodywork designed for the zero motorcycles. And it should give you better, um, range.

The, on the freeway in particular, the another project we're really excited about is a, um, a regenerative brake lever. So that's where you have variable region and a brake lever on the left side. Cause you don't need a clutch on these bikes. And by using that, you can increase your range by about 10%, which is again, a pretty significant number on the freeway because at 60, 70, 80 miles an hour, you, you really slow.

You, you really get a lot of drag and every time you touch the brakes, you're effectively wasting energy. So if you can hit the region lever as your regular brake lever, um, it will save a lot of that energy. So that's that doesn't exist. I'm really shocked that it still doesn't exist as a stock offering because it's not that difficult to do.

So we're, we're going to be offering that as an aftermarket item for the zeros. And I think we can set it up on other electric motorcycle brands as well, but for now we're focused on the, the largest one.

[00:39:08] Randal R. Jacobs: I've looked at electric motorcycles and I've always been surprised at, um, how poor the rain, the peak range tends to be given how much heavier they are than a standard bike. And it's, you know, aerodynamics at speed, the aerodynamics of a motorcycle with a rider on it. There's so many variables, there's so much vortices shedding happening off of the rider.

And like that fairing kit makes a ton of sense for extending range. And then it's a region is a, another level of complexity versus a car because your weight distribution is one.

opposite what you would want. So it's your rear with it. You have power going, and if you're going to use the motor to go send it into region mode, well, when you're braking, it's shifting weight onto the front wheel. So that's a challenge. And then there's control issues that you don't have with a, with a four wheeled vehicle that you do have with a motorcycle that has any sort of input that isn't completely controlled by the rider. So like being able to feather that Regene brake makes a ton of sense.

[00:40:04] Craig Calfee: it's super helpful. I mean, it's it's night and day difference. The stock offering is a fairly low region level that's on or off. When, when you're released the throttle, you can set your settings can be, can be set up to have heavy region or light region. And it's just the heavy region just feels real jerky and you don't really use it as you're just decelerating in normal traffic.

It's just, you know, it's eco mode basically where variable region lever, it gives you. You know, region all the time and exactly the amount you want for two, and then you use it all the time and you only use the real break for emergency braking where you do need that front wheel to get loaded up and slowing you down right now where the region it's more for deceleration than real breaking.

[00:41:00] Randal R. Jacobs: Yeah, I've thought about that on e-bikes as well, where, you know, having the rear brake, essentially the first portion of its travel, go add some regenerative elements and then go into actually engaging the disc brake rotors.

[00:41:16] Craig Calfee: Yeah

[00:41:16] Randal R. Jacobs: so then we get,

[00:41:17] Craig Calfee: good.

[00:41:17] Randal R. Jacobs: How about this race car that you had in there? Is that allowed to be spoken about.

[00:41:20] Craig Calfee: Yeah. Well, the, the race car was, was a special project of a friend of mine. And we did some carbon repair work on it, and I think there was some battery swapping going on. Um, so we have, we have friends in the, in, in the racing electric race car circuit that loves the fact that we can fix a broken carbon.

So, you know, they, they tend to get wild out there in the racetrack. And so, and we're not far from Laguna Seca, so they, they come by here and we do some work on their cars.

[00:41:55] Randal R. Jacobs: really a, it's really a special space that you have down there and you get the air, you get that local airport right behind you. It's a very kind of quiet, tranquil sort of area generally now. Not far from the coast.

[00:42:07] Craig Calfee: Yeah, we're right on the coast. And the airstrip is a fun place to do tests. Um, yeah. And other companies that come combine to do tests on our airstrip Polaris has a new electric, um, off-road quad vehicle that they're doing in partnership with zero motorcycles. And they came down and did their range test on our airstrip.

So that was, that was fun to see the first one. So we kind of got a sneak preview of that product.

[00:42:36] Randal R. Jacobs: I'll come pay you a visit next time. I'm in California. It's been a, it's been a while. It's been a few years. All right. So then let's see a few last things to finish up with. So, um, you mentioned last, we spoke about in an electric motorcycle project that you've been working on in Africa.

[00:42:53] Craig Calfee: Yeah. That's really fun. It's, it's basically a an ambitious plan to replace all of the nasty polluting, low displacement gas burning motorbikes that are, that represent about three quarters of the number of motorcycles sold in the world. You know, all the motorbikes you see in the streets, in the U S you know, most of them, the higher, the bigger bikes.

There that represents a very small portion of the market. So these are the 1 25 CC bikes that are used for pretty much everything in developing countries, they're taxi bikes, their cargo bikes, they move more stuff than almost anything else in, in most of the world. So they're not very well-regulated for their pollution.

And they're expensive to maintain. And gas prices in developing countries are subject to unstable conditions and in both supply and demand and, and corrupt practices that cause prices to fluctuate so that you can have your business model of being a motorcycle taxi. But your cost of doing business varies too much, and it makes it really hard to make a living.

So we found now that an electric motorcycle where you have a battery swap a business model, Which means you don't have to buy the battery. You just rent the battery that reduces the cost of ownership significantly. And then you can have these battery swap stations that are solar powered. So very low costs, not reliant on an unstable grid and provide steady power for critical transport infrastructure.

That is also not only economically feasible, but allows for the same entrepreneurs to still make money more steadily with with a cleaner energy. So it's it. Every time you turn around on this thing, you're saving money to no maintenance. Um, you know, these, these bikes they're constantly breaking down.

They're spending money on spare parts. Sometimes the bike sits for months while they wait for spare parts. Just the, that whole infrastructure is a disaster, but, um, the electric side is much easier to manage. And if the batteries are managed centrally by a company, so they're managing the charging and discharging of the batteries more strictly would they're maintaining the batteries properly.

And we're in into the modular battery concept, similar to the LIGO batteries. In fact, our prototype was built with LIGO bricks, where if any, one of those went bad, we could just open the battery up and swap out one of the bricks. And the brick is 10, 10 cells. So usually electric motorcycles have these monolithic giant batteries.

And if one cell goes bad in that pack, then that's a, that's a thousand dollar. You know, replacement part and that's just too expensive. So I'll all my battery engineer, friends are big fans of modular batteries where you can go in and replace either one cell or one, one pack of a cell. So that's, that's really, um, you know, exciting and cutting edge technology right now.

[00:46:16] Randal R. Jacobs: It's a lot of, um, a lot of like multi-variate optimization looking at, say like a remote village that may not have good infrastructure for transporting gas, but then also has abundant sunlight and maybe the grid infrastructure, as you said, isn't stable, or maybe it hasn't even reached in a lot of places, but put up some solar panels you could literally like, you know, have a 20 foot container built out as a little repair and.

Surging station with wings at fold up and just drop it in there. And all of a sudden you have a hub for generating power and maintaining an entire fleet. You can even have financing for people who want to get a motorcycle can have access to these batteries, because everything is so much more predictable because you've controlled so many of the cost variables and so on.

So this is, this is quite interesting.

[00:47:00] Craig Calfee: it's huge. I mean, back to the financing side. So getting funding for projects like this is difficult because it involves investors throwing money down on to expensive stuff, you know, inventory or assets that get distributed into a, into a region that is notoriously unstable in terms of security of assets, things get stolen, things get, you know, broken and not tracked well.

So we put trackers on these batteries. So the tracker follows the battery, not the bike, and it just, we're just tracking these thousand dollar battery packs and the investors feel very confident about. And if somebody ends up with a battery and doesn't either doesn't return it or tries to charge it up on their own and they don't re you know, we can track where the location of that battery is and go get it if necessary.

So that discourages people from trying to cheat the system, cause they don't want to deal with the police which are much more severe than they are here. It's not like they'll just come in and you know, these are like repo squads and they will, it's the wild west, you know, you just don't want to deal with that.

So people don't, they just, they cooperate, they pay their bill, they return the battery, they get a fresh one and every everything's good and it's cheap enough that there isn't that much incentive to try to gain the system. So back to the investors, they love that. And therefore a lot of money becomes available to, to throw at this incredibly huge market.

there's all of these development projects. People say, oh, well, why don't you just, you know, donate that stuff or, you know, get a nonprofit started up psych. Well, actually we've been trying that for hundreds of years and it generally doesn't work. So you really need economically sustainable businesses to, to get supported and continue running profitably so that they can, can, you know, just run without the need for donors to constantly give them free.

[00:49:14] Randal R. Jacobs: It's something that, that actually resonates a lot with. Kind of how my thinking has evolved on such matters. Like you can have a population of people that may, at some point in history have been victimized, but continuing to treat them like victims versus giving them the tools of empowerment and being like, okay, we're going to create a viable economic model.

And ideally as th