I'll tell you another inside story on building the prototype. The XR2 had been pretty much designed, but building a prototype was on the back burner, where it had been for over a year. I was really excited about building it, but more pressing things kept getting in the way. So a writer from WIRED magazine called and said they'd like to do a piece on my website. Naturally I was excited about it. His next question was: "Do you have anything new to photograph?" So in my bravado, I replied: "Well, we have this new carbon fiber recumbent bicycle. It's really a knockout, but the prototype isn't done yet." To which he replied: "We'll wait. How long till it's done." And without breaking a sweat, I replied: "Oh, about four weeks." So that's how I cornered myself into building a prototype. Best favor a writer ever did for me. You can see an image of the one-page photo spread that ended up in WIRED at http://www.rqriley.com/images/wired-2.jpg |
BRK: Shortly before his untimely death, we had an interview with Bruce Bursford, designer of The Ultimate Bike and holder of a great many UCI-recognized bicycle speed records, including the World Time-Trial record, which he broke in August 1999, at times exceeding 52 MPH on a road course. The Ultimate Bike is a Carbon-composite vehicle of conventional (UCI-sanctioned) bike configuration. The bike itself was designed to be as lightweight, stiff, and aerodynamically slippery as possible, with state-of-the-art, aerospace-derived bearings for minimal mechanical friction. The weight of the machine in road trim is about 11 pounds, supposedly. Bruce built himself up to Herculean proportions for the campaign, developing thighs 33" in circumference in the process. Extremely powerful, but not what we would necessarily consider an aerodynamic powerplant. I was never able to inveigle him into discussing other (recumbent) configurations. This reticence on his part is not surprising when one considers that he was in the business of manufacturing $35,000 bikes of the UCI-sanctioned type, and breaking UCI records. I think we may take as a given that the recumbent form is superior, both bio-mechanically and aerodynamically, to the UCI-sanctioned form (What 'bent jockeys call a "wedgie"). So, our theoretical question is: how fast would Bruce Bursford have been able to go on that World Time- Trial attempt if he'd been riding a Ground Hugger XR2, rather than the UB?This conjecture is based upon the assumption that the XR2 would be fitted with comparable bearings, tires, etc. As an XR2 frame in naked carbon weighs about 5 pounds, the weight would be pretty much comparable, I should think. Of course, a powerplant like Bruce might require more carbon fiber in the frame, to achieve the extreme strength and stiffness needed to handle the power he was capable of generating, but the machines are at least roughly equivalent, I think. I realize that this is much like one of those Jack Dempsey Vs.Muhammad Ali discussions one overhears in sports bars, but it would be really interesting to hear your rough conjecture on such a comparison. RQR: Assuming both men were in their prime, I think Muhammad Ali would win. But I happen to be biased toward Ali. Likewise, I think a super-light carbon fiber recumbent would do better on a flat-out run. That statement comes from what I know of historical events, my own experience with Ground Hugger, and a personal mindset on design efficiency. Admittedly, the last two are pretty subjective because I've never done any controlled comparisons. When we built the first Ground Hugger back in the '60s, one of the most obvious priorities was to determine just how fast this new creation would go. These early bicycles weighed about 45 pounds, and were equipped with Sturmey Archer 3-speed hubs. Tires were the old-fashioned low-pressure type. Neither of us were trained cyclists, but we were in |
BRK: There's an apt expression I heard in Kentucky once: "We went to different schools together." Speaking of inelegant solutions-when I was that age, I came up with a water desalinization scheme which involved electrolysis to separate water into its component elements (Hydrogen and Oxygen). These would then be recombined, continuous-explosively, into pure water. Fortunately, I never got around to setting up the pilot plant. Getting back to Ground Hugger: Since bikes based upon the design have been in continuous construction for thirty years, it should logically be considered a classic. Do you have any idea how many have been built over the years? And is there some sort of association of owners/builders, like a Ground Hugger Registry? It would be great if there were some sort of periodic gathering, where hordes of them could be seen in one place. And just imagine the parade.... RQR: Some 15,000 sets of the original Ground Hugger plans are floating around out there, but I don't have a clue how many have been built.Unfortunately, folks normally don't let me know when they finish their projects. Usually, I find out about them quite by accident. About six months after HydroRunner(a little PWC-type boat) plans were released, I was driving down a street just four blocks from my house and spotted a beautifully finished one sitting on a trailer in someone's driveway. We're practically neighbors and the builder had never contacted me. A Trimuter (a three-wheel car) pulled up beside me at an intersection, and I had never heard from this fellow. I had to follow him to work in order to talk to him. Occasionally I come across a finished project on someone's personal website. Take a look at the Tri-Magnum at http://members.aol.com/nokaj/TriMag.html. I accidentally found it while searching keywords to see how my website rated. And yes, I'd very much like to establish a network hub for the Ground Hugger. It would be easy enough to set up as a sub-web of my website. So I'd be interested in hearing from folks and getting their suggestions on what type of site they would like to see. As long as the interest is there, I'll do it. And that goes for kits and completed bicycles. Interest in the new XR2 is many times greater than with the original version, so I'm looking forward to more developments. It has already become the top-selling plan at my website. |
Robert Q. Riley is a pretty amazing guy. He designs all sorts of interesting things, everything from cars to hovercraft to submarines. After he's built it, he writes the equivalent to a book, telling ordinary people how to build one for themselves. He is a solid designer and stylist, his plan-sets are fine examples of the art, and he is an excellent how-to writer. His first plan-set was for a rather revolutionary bike design, which re-invented the pretty-much-forgotten recumbent bike configuration. (Click here to see a lost one from the '30s). Called Ground Hugger, it was designed to be built from steel tubing and salvaged bike components. I remember being quite impressed with it, when Ground Hugger and its plan-set were featured in Popular Mechanics Magazine, in 1969. Recently, Robert Paterson, one of our Australian readers sent us photos for our gallery, of a Ground Hugger he had built from Mr. Riley's plans. I visit Mr. Riley's site fairly regularly, to see what he's up to. As it had been a while since my last visit, I checked in again. Imagine my surprise to find an announcement to do with a new version of Ground Hugger: the XR2, designed to be built from carbon fiber and vinylester resin over carved foam. The launch of the new machine seemed like the perfect occasion to do an interview with Mr. Riley, and to review the new plan-set. |
Godfather of the Modern 'Bent: Robert Q. Riley BikeRod&Kustom Interview By Jim Wilson BR&K Editor-In-Chief |
Robert Q. Riley is a pretty amazing guy. He designs all sorts of interesting things, everything from cars to hovercraft to submarines. After he's built it, he writes the equivalent to a book, telling ordinary people how to build one for themselves. He is a solid designer and stylist, his plan-sets are fine examples of the art, and he is an excellent how-to writer. His first plan-set was for a rather revolutionary bike design, which re-invented the pretty-much-forgotten recumbent bike configuration. (Click here to see a lost one from the '30s). Called Ground Hugger, it was designed to be built from steel tubing and salvaged bike components. I remember being quite impressed with it, when Ground Hugger and its plan-set were featured in Popular Mechanics Magazine, in 1969. Recently, Robert Paterson, one of our Australian readers sent us photos for our gallery, of a Ground Hugger he had built from Mr. Riley's plans. I visit Mr. Riley's site fairly regularly, to see what he's up to. As it had been a while since my last visit, I checked in again. Imagine my surprise to find an announcement to do with a new version of Ground Hugger: the XR2, designed to be built from carbon fiber and vinylester resin over carved foam. The launch of the new machine seemed like the perfect occasion to do an interview with Mr. Riley, and to review the new plan-set. |
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Ground Hugger, 1969. All Images © 2000 Robert Q. Riley Enterprises |
BRK: Let's see if I've got this straight: You're your own boss, you design any amazing thing you feel like, you have the fun of building it, then people pay you a decent amount of money for showing them how to make one like it. Assuming that this is all so; would it be safe to say that you are an extremely happy guy? And how did you happen to get into such a sweet racket-I mean-career? RQR: The question is "How did I get into the build-it-yourself business, and does doing all these fun things make me a happy guy?" I went into the business of selling plans pretty much by accident. In the early '60s, I ran a large Schwinn dealership in Southern California, and came up with what I believed was the very original idea of making a low-slung bicycle. Back then, I had never heard of a recumbent bicycle. So I joined forces with a high-school friend, Dave L. Carey, and built a prototype. It turned out to be a pretty good bicycle. But none of the bicycle manufacturers were interested in taking on the design. As a last resort, I queried Popular Mechanics magazine on the idea of doing a plans-built project. They agreed and it was featured as "PM's Ground Hugger." Plans sold like hotcakes. That was my first plans project for a magazine, and it led to a whole series of projects for Popular Mechanics, and in the old days, Mechanix Illustrated magazine. By the late 80's I had moved on to the consulting business. But today, my website brings in far more on the sales of plans than the consulting part of my business, and it's actually a lot more fun. So you'll be seeing lots of new products, the first of which is the Ground Hugger XR2. There's also a line of CD-ROMs under development. So does it make me happy? My business is very gratifying, and I feel extremely lucky to be doing what I'm doing. I'd do the creative stuff for nothing if I could figure out how to live without eating. But like any business, it demands lots and lots of work, and it takes lots of income just to meet the overhead. For example, the cost to develop the new Ground Hugger XR2 - designing it, building the prototype, then developing and publishing the plans - has already topped $50,000, and expenses are still mounting up. That part of it tends to take some of the fun out of it because it demands that I use my time in ways that generate income. So I get to have my "fun" only if it's profitable. But the answer is "yes." I am a happy guy, and what I do for a living is very rewarding. I can't think of anything I'd rather be doing. |
BRK: $50,000! Having fun is certainly expensive nowadays. Although I've gotta say that the XR2 looks like a million bucks; so maybe it's a bargain. For comparison, what would you estimate the development costs of the original Ground Hugger to have been? On the assumption that the difference is perceptible, what factors account for the difference? RQR: I don't recall the development cost of the original Ground Hugger. But if I had to guess, I would put it at about $200. That's based on the fact that we worked for free to develop it, and made drawings on notebook paper. As for the bicycle itself, the quality of design is pretty much self-evident. And if you were to compare the old hand-drawn Ground Hugger plans with today's XR2 plans- especially the plans with the CD-ROM containing 3D models, CAD drawings, and multimedia animations- the difference in quality would also be self-evident. There's just no comparison. |
BRK: I haven't seen the CD-ROM yet, but the paper part of the XR2 plan-set is really slick; and the 3D graphics make for a big difference in the clarity of the construction manual. Aside from the development cost difference, could you give us an idea of how the two machines differ in specs and performance? I notice that your site still offers the original Ground Hugger plan-set; will that continue, or are you planning to phase it out? RQR: The original Ground Hugger will not be phased out. Some folks are more comfortable working with bent metal tubing than with carbon fiber. So the original metal-tube-frame Ground Hugger will stay around. The advantages of the new XR2 center on its carbon fiber frame, and the fact that it comes from about 30 additional years of design experience. It has a modern suspension system, and it's designed around modern components. Carbon fiber composite and much of the hardware used on the XR2 wasn't even available back when the original Ground Hugger was built. So a lot of the difference is in the details. Consider that the basic architecture of the bicycle hasn't really changed much in the last 100 years. But today's bicycles are far superior, mainly because of design refinements and superior components-the details. The carbon fiber frame has big advantages. We all know about the weight-saving benefits. The XR2's frame weighs less than half that of the original Ground Hugger - just over 6 pounds with the filler applied to the surface, or barely 5 pounds in a natural finish. But for me, one of the biggest benefits of carbon fiber composite is the freedom of design it gives you. This has both mechanical and styling implications. For example, loads are not evenly distributed over a bicycle's frame. So in order to design to the loads, the cross-section of the frame should be larger in areas of high loads, and smaller in areas of lower loads, and wall-thickness should vary as well. Using off-the-shelf materials, this is virtually impossible to achieve with metal tubing (for the home craftsman). It can be achieved, however, using carbon fiber composite. So the load-bearing efficiency of the frame is much greater. Plans are written to the design freedom of carbon fiber composite. In other words, we assume that the builder will want to personalize his bicycle. So plans provide the technical information necessary to make sound modifications. You can actually build just about any bicycle with the type of construction technique used on the XR2. The final benefit of the XR2 has nothing to do with practicality and everything to do with the spiritual dimension. As an industrial designer, the issue of styling is a very personal one for me. Our machines let us go beyond our normal human limitations. My computer can calculate faster than a million mathematicians, and my car can run faster than the fastest racehorse on earth. So I transcend my normal human limitations by using one of these inventions. There's a kind of beauty in this, and the machine should look as beautiful as it works. It should be beautiful in form as well as in function. When a vehicle works well but esthetically falls short, then I feel deprived of an inner pleasure and it becomes difficult for me to fully enjoy what it does. So, contained within the form of the XR2 is a very personal statement on design. |
BRK: As an aficionado of plans-built vehicles, I've always been struck by the attention to visual detail and styling of your designs. I'd always assumed that you got into this field through a background as an industrial designer/stylist. Were you trained in that field, or are you what we would call "a natural"? It only occurs to me to ask because of your earlier statement that you were running a Schwinn dealership when you designed Ground Hugger. RQR: I think I'd be classified as a "natural," since I'm not formally trained as an industrial designer. Today, I'm a member of the IDSA and SAE, and have nearly 30 years experience in mechanical engineering and industrial design. But my early training is actually in business administration. I managed a large sporting goods store in San Fernando Valley (LA area) until 1973. We were the local Schwinn dealer, and had an in-house bicycle repair shop. Design was always my first love, but nobody ever told me you could actually make a living doing it. On second thought, maybe you can't. I'd have to say that much of my success is based on fundamentally sound business skills. |
BRK: I imagine that innate intelligence is of equal relevance in this case. Many worthy business endeavors have been run into the ground by less-than-brilliant MBAs. Education aside, were you the kind of kid who was always drawing dream cars and spacecraft? RQR: Yes. I was drawing vehicles from the time I could pick up a pencil -cars, planes and anything else that moved. I went through a flying saucer phase at about age 13, and even laid out the power system showing how the anti-gravity system would work. As I remember, it worked by artificially generating a gravitational force, then electronically reversing the polarity to make it repel instead of attract. The idea of propelling a spacecraft by the brute force of a continuous explosion seemed very inelegant, even at age 13. At about the same period, I began reading college-level textbooks on physics because I was fascinated by how it all worked. This was my entertainment. Then I discovered sex, and it turned out to be a lot more fun than theoretical physics. |
BRK: There's an apt expression I heard in Kentucky once: "We went to different schools together." Speaking of inelegant solutions-when I was that age, I came up with a water desalinization scheme which involved electrolysis to separate water into its component elements (Hydrogen and Oxygen). These would then be recombined, continuous-explosively, into pure water. Fortunately, I never got around to setting up the pilot plant. Getting back to Ground Hugger: Since bikes based upon the design have been in continuous construction for thirty years, it should logically be considered a classic. Do you have any idea how many have been built over the years? And is there some sort of association of owners/builders, like a Ground Hugger Registry? It would be great if there were some sort of periodic gathering, where hordes of them could be seen in one place. And just imagine the parade.... RQR: Some 15,000 sets of the original Ground Hugger plans are floating around out there, but I don't have a clue how many have been built.Unfortunately, folks normally don't let me know when they finish their projects. Usually, I find out about them quite by accident. About six months after HydroRunner(a little PWC-type boat) plans were released, I was driving down a street just four blocks from my house and spotted a beautifully finished one sitting on a trailer in someone's driveway. We're practically neighbors and the builder had never contacted me. A Trimuter (a three-wheel car) pulled up beside me at an intersection, and I had never heard from this fellow. I had to follow him to work in order to talk to him. Occasionally I come across a finished project on someone's personal website. Take a look at the Tri-Magnum at http://members.aol.com/nokaj/TriMag.html. I accidentally found it while searching keywords to see how my website rated. And yes, I'd very much like to establish a network hub for the Ground Hugger. It would be easy enough to set up as a sub-web of my website. So I'd be interested in hearing from folks and getting their suggestions on what type of site they would like to see. As long as the interest is there, I'll do it. And that goes for kits and completed bicycles. Interest in the new XR2 is many times greater than with the original version, so I'm looking forward to more developments. It has already become the top-selling plan at my website. |
BIG PLANS FOR EVERYBODY! In addition to his bike plans, Robert Q. Riley has created a vast number of plan-sets for home vehicle builders. Shown here are most of them. Click on the photos for more information. |
Tri-Magnum A high-performance three-wheel sports car. |
AquaSub A one-man sports submarine that operates in the near-surface environment. |
Doran A high-performance three wheel sports car for either gasoline or electric power. |
MiniHome Is built on a VW Bug chassis and has compact motorhome-style facilities for four. |
UrbaTrike Cruises at 55 mph and runs 50 miles on its eight 6-volt golf car batteries. |
Centurion Achieves 128-mpg fuel economy on its diesel engine. |
HydroRunner A high-performance personal watercraft using an outboard engine. |
Trimuter Accepts either battery-electric or ICE power. |
UrbaCar Tops 60 mph and delivers 55 mpg fuel economy. |
Gluhareff Pressure Jet Engine A fully throttleable jet engine available in 20-lb, 40-lb, 80-lb, and 130-lb thrust sizes. |
Town Car A series hybrid-electric vehicle. |
Pegasus Hovercraft for youngsters. |
Budget Camper Fits long-bed American pickups. |
Urba Electric Test bed for proving out the CVT speed control system for EVs. |
Boonie Bug A VW-van-based minivan. |
Tri-Flyer A three-place, high-performance hovercraft that can top 80 mph. |
Phoenix Expands tent-trailer style into a large camper. |
Carbon Fiber Groundhugger XR2, 2000 |
BRK: Shortly before his untimely death, we had an interview with Bruce Bursford, designer of The Ultimate Bike and holder of a great many UCI-recognized bicycle speed records, including the World Time-Trial record, which he broke in August 1999, at times exceeding 52 MPH on a road course. The Ultimate Bike is a Carbon-composite vehicle of conventional (UCI-sanctioned) bike configuration. The bike itself was designed to be as lightweight, stiff, and aerodynamically slippery as possible, with state-of-the-art, aerospace-derived bearings for minimal mechanical friction. The weight of the machine in road trim is about 11 pounds, supposedly. Bruce built himself up to Herculean proportions for the campaign, developing thighs 33" in circumference in the process. Extremely powerful, but not what we would necessarily consider an aerodynamic powerplant. I was never able to inveigle him into discussing other (recumbent) configurations. This reticence on his part is not surprising when one considers that he was in the business of manufacturing $35,000 bikes of the UCI-sanctioned type, and breaking UCI records. I think we may take as a given that the recumbent form is superior, both bio-mechanically and aerodynamically, to the UCI-sanctioned form (What 'bent jockeys call a "wedgie"). So, our theoretical question is: how fast would Bruce Bursford have been able to go on that World Time- Trial attempt if he'd been riding a Ground Hugger XR2, rather than the UB?This conjecture is based upon the assumption that the XR2 would be fitted with comparable bearings, tires, etc. As an XR2 frame in naked carbon weighs about 5 pounds, the weight would be pretty much comparable, I should think. Of course, a powerplant like Bruce might require more carbon fiber in the frame, to achieve the extreme strength and stiffness needed to handle the power he was capable of generating, but the machines are at least roughly equivalent, I think. I realize that this is much like one of those Jack Dempsey Vs.Muhammad Ali discussions one overhears in sports bars, but it would be really interesting to hear your rough conjecture on such a comparison. RQR: Assuming both men were in their prime, I think Muhammad Ali would win. But I happen to be biased toward Ali. Likewise, I think a super-light carbon fiber recumbent would do better on a flat-out run. That statement comes from what I know of historical events, my own experience with Ground Hugger, and a personal mindset on design efficiency. Admittedly, the last two are pretty subjective because I've never done any controlled comparisons. When we built the first Ground Hugger back in the '60s, one of the most obvious priorities was to determine just how fast this new creation would go. These early bicycles weighed about 45 pounds, and were equipped with Sturmey Archer 3-speed hubs. Tires were the old-fashioned low-pressure type. Neither of us were trained cyclists, but we were in |
reasonably good shape and in our early twenties. So with us twenty-something non-athletes riding 45-pounds of hardware, we were able to clock about 33 mph on level ground - no record, but not bad.I don't believe that you could ever match the weight of an ultra-light upright bike with a LWB recumbent, mainly because of the length of the frame, the extra chain, and the steering mechanism necessary for the recumbent. But the weight difference would not be much of a factor in terms of maximum speed. Air resistance is by far the most important factor with speeds on the order of 50 mph or more. And according to my experience with Ground Hugger, you can apply much greater pressure to the pedals because you can push against the back of the seat. You may not be able to do it continuously, but for short bursts you can deliver more power to the pedals. So I think a low machine like the XR2 would do better in the hands of a trained athlete. |
BRK: Speaking as a fearless fan of both Bruce Bursford and R.Q. Riley, I think that the XR2 would do 75mph, if propelled by Bruce. And with a suitable fairing covering the "powerplant" I'd say it would top100mph. If we were having this discussion in a sports bar, I'd probably say 125mph. Of course, Bruce is unavailable, so I can make those statements without fear of contradiction. Regarding the XR2's fantastic segmented seat design: does it look that way for engineering reasons, or because it's a lot cooler-looking than a one-piece seat? |
RQR: What a good beer-drinking buddy you'd make! First you tell me how smart I am, and then you say my bike will go 100 mph. I'll buy if you'll keep talking. Maybe after a few beers we could get it up to 150 mph. But the official IHPVA (International Human Powered Vehicle Association) speed record for a fully-faired recumbent is 68.72 mph. And I think it has at least as much to do with the operator as the machine. On second thought, with someone like Bruce Brusford at the controls, maybe, just maybe, we could do it! There's an interesting story around that segmented seat design. I have used a similar architecture before on seats, and not only does it look extremely cool, it also works very well. You can't feel the separate pads when you're sitting on it. It feels as though the seat is made from a solid piece. And you're right, it does provide air circulation to keep your backside from overheating. The seat design began when I was considering the idea of revising the plans for the original Ground Hugger and updating it with modern components. The first thing I did was model the bike in 3D and redesign the rather old-fashioned looking seat, which is where the segment design comes from. But when I looked at the 3D model, things didn't look right. The seat was just too cool for that bent-metal-tube bike. So it quickly became obvious that what I needed was a new bicycle design to go with the seat. At that point, I decided to start with a clean sheet of paper and really go for it. And that's how the XR2 came about Once I got into the design, the excitement I felt about Ground Hugger back in the '60s began to emerge again. So it has been a huge turn-on for me. And it's especially meaningful because it was Ground Hugger that started my design career in the first place. |
BRK: That's really funny! Have you started work on that prototype personal spacecraft yet? Another of my favorite XR2 design touches is the rear stays. You give two alternate methods for building those pieces-the simpler of the two is fabricated from 1/4" aluminum plate, the more complicated is the hollow tubular version, which is built-up from 1/4" and .065 stock. It gives greater lateral stiffness and would look |
incredible when polished, I'm sure.While studying it, I thought of a third method: carbon fiber over foam sculpted to the form of the tubular stay, bonded to the flat-plate stay. It would seem to be somewhat easier to make, while achieving the greater stiffness of the hollow aluminum unit. Any thoughts on that? RQR: Interesting that you mention a composite rear stay. We considered a similar approach. Elusha Abdurakhmanov, the fellow who did much of the 3D modeling on the XR2, kept pushing for a composite rear stay, with foam overlaying an aluminum substructure similar to what you describe. But I was against the idea. In fact, I finally told Elusha that I was going to tape a barf-bag to the back of his chair so I'd have something to reach for whenever he called me over to look one of his new ideas on it. (I'm not really opinionated, rude and insulting. It's just part of the fun around here.) I like the idea of a composite rear stay. But there were a couple of negative attributes that I couldn't get past. First of all, the idea of overlaying the flat stay with foam and carbon fiber to make it stiffer feels abrasive to me because it's doing patchwork. Plus, it would make a stay that is already slightly overweight just that much more so. Moreover, if the design is so bad that it needs to be patched up, then it ought to be tossed out for a better one. But in reality, when riding the XR2 with the flat stay, I cannot feel flexibility at the rear. And the flat stay is about as simple to build as one could ask for. And, it's still pretty light. But if you grab the rear wheel in one hand and the frame in the other and twist it, there is more flexibility than I would like to see, which meant to me that we were likely to get complaints from the more discriminating cyclist. So once I invented this hypothetical "more-discriminating-cyclist," I felt as though I ought to please him. In my mind, this fellow would also be the one most likely to complain about the unnecessary weight of the flat stay assembly. He would be more of a purist. And it's true. We've traded ease of construction for extra weight with the flat stay assembly. So if we were to design a stiffer stay, it ought to be lighter as well. That left two options: A totally composite stay with metal fixtures at the ends (for the hanger up front and the dropouts at the rear), or a built-up aluminum stay. I was reticent about the idea of expecting the home craftsman to build a highly stressed stay assembly of carbon fiber composite. (The stay is subjected to much greater stresses than the frame.) Technically it's a very good option, but I just didn't believe it was the right way to go for the home craftsman. That left the built-up aluminum stay. The built-up aluminum stay is roughly 20% lighter and about three times stiffer than the flat stay assembly. And it can be polished out to match the appearance of the fork. I'll bet you thought that was a simple question. |
BRK: Believe me, I've played the design game long enough to have caught on that there are no simple questions or answers. It's what keeps the game amusing. Quite a coincidence your mentioning that "more-discriminating-cyclist" guy. I know the fellow well; and he's a real pain in the ass! So, what does he have to say about the XR2's front fork? RQR: Actually we haven't received any complaints, even from the more discriminating cyclist. |
The fork on the XR2 is solid as a rock, it's very easy to build, and it's still pretty light. It weighs just over one pound, or about 453 grams. It's certainly possible to build a lighter one. But you'd be hard pressed to design a fork that's easier to build. |
I'll tell you another inside story on building the prototype. The XR2 had been pretty much designed, but building a prototype was on the back burner, where it had been for over a year. I was really excited about building it, but more pressing things kept getting in the way. So a writer from WIRED magazine called and said they'd like to do a piece on my website. Naturally I was excited about it. His next question was: "Do you have anything new to photograph?" So in my bravado, I replied: "Well, we have this new carbon fiber recumbent bicycle. It's really a knockout, but the prototype isn't done yet." To which he replied: "We'll wait. How long till it's done." And without breaking a sweat, I replied: "Oh, about four weeks." So that's how I cornered myself into building a prototype. Best favor a writer ever did for me. You can see an image of the one-page photo spread that ended up in WIRED at http://www.rqriley.com/images/wired-2.jpg |
