BMX Plus! Carbon Concept Review. June 2012 Issue
!0 -,$' #0 !-,!#.2 IS THIS THE FASTEST BIKE MONEY CAN BUY?
or years, being fast was a skill that had to be earned, requiring countless hours in the gym and at the track to hone the necessary skills to win at the highest level of competition. If you were a fast rider, you were fast on whatever your sponsor put under your feet, but today, the winds are changing. With riders so expertly trained and evenly matched, the smallest details could lead to the biggest wins. This is where we got the idea for our carbon fiber concept bike. With so much advanced technology on the market today, how much performance can a rider buy their way into when they are at a level where each millisecond really matters? Weight and stiffness matter in a bike, and knowing you could have bought your weight down or invested in stiffer parts could weigh heavy on a rider’s mind, especially when that rider is consistently losing races by a wheel. Now consider you are a member of your country’s Olympic BMX team and an entire nation’s eyes are looking to you to win. Forget a NAG plate, forget the Redline Cup, don’t even bring up the Worlds—we are talking about the single most important lap a rider will ever take, the Olympic main event. Is there any price a company could present to you that would be too high for that extra microsecond on the clock or millimeter on the track? Not a chance. With this in mind, we decided to build the ultimate racing machine for the lap of a lifetime.
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$0+# The Redline P79 carbon fiber frame is the ultimate in race performance. Weighing only 2.8 lbs, it not only gives the rider a lightweight advantage, it is also incredibly stiff thanks to its one-piece, molded structure that encases integrated aluminum headset cups, a Euro bottom bracket shell and enclosed 15mm dropouts with integrated tensioners. $999
$-0) Our fork of choice was the Answer Dagger carbon fork. Weighing 24 ounces, it is lightweight, stiff and thanks to its integrated aluminum crown and dropouts, it is plenty strong for what the Olympic track might have to offer. When paired with the frame, it offers unrivaled balance, rigidity and handling. $269
Kendaâ€™s new Kompact tires were a great match for our project with a micro, directional tread designed for fast, hardpacked courses, a 60-tpi casing rated up to 100 psi for minimal rolling resistance, and a foldable bead that helps it achieve its status as one of the lightest race tires available at only 365 grams. We chose 1.75-inch front and rears to keep both the weight and rolling resistance to a minimum. $29 each.
Since rotating weight must be kept at an absolute minimum on this project, we chose Maxxis Ultralight tubes. At only 83 grams for a 1.5- to 1.75-inch size, it is one of the lightest production tubes available that wonâ€™t leave you flat on the gate. $11 each
Since our goal is the lap of a lifetimeâ€”not laps for a lifetimeâ€”we didnâ€™t hesitate to cut a lot of weight and bypass chromoly bars for a set of Bombshell Carbon Pro bars. Made with a 3K, 2x2, twill, carbon fiber weave, they are the lightest option available for riders under 200 pounds at only 12.4 ounces. They have an 8.25-inch rise, 28-inch width and retail for $239.
1#2.-12 With nearly everything going to pivotal, it was only a matter of time before the pivotal post was offered in carbon fiber for a feathery alternative to low-abuse racers. The carbon pivotal post from Supercross features an aluminum core for strength and clamping rigidity, but with a carbon wrap to save weight. Clean and simple. $54
HEADSET AND SPACERS Since any resistance robs energy and could mean the difference between Olympic gold and a walk of shame, we went with lightweight performance that we trust. Speedline’s integrated headset uses only the highest-performance sealed bearings and pairs them with lightweight aluminum races and hardware to chase away the grams. To pull it all tight, we spaced out our head tube with Speedline’s Carbon spacers, available in packs of three, and without a doubt are the lightest option when it comes to headset spacing. $39 for the headset and $10 for the spacer kit.
SPROCKET We juggled a few sprockets before we chose to go with Tangent’s 4-Bolt ring. CNC-machined from 6061T6 aluminum, the 4-Bolt is 5mm wide and designed for a smooth and friction-free interface with any 1/2 by 3/32-inch chain. Weighing 4.5 ounces in a 44-tooth size, there are slightly lighter-weight sprockets on the market; but we needed a durable sprocket to handle the load of our powerful drivetrain, and for a few extra grams, that sort of durability builds necessary confidence in the gate. $39.
CHAIN Our bike needed a lightweight and durable chain, so we went with a featherweight design we have trusted for years, the Speedline Superlite full link. Halflink chains are great for a moderate load, but when it comes to Elite pull and the high-power transfer rate of our bike, a full-link chain was a must. The Superlite features hollow pins and large void link plates to save weight, but it also benefits from a patented heattreating process to maximize strength. $39
SPROCKET BOLTS No detail was spared on this ride, where even the chainring bolts are trick. The Torx T-30 chainring bolts from FSA are made from cold-forged 7075/T6 alloy for strength and durability and designed for use with a Torx wrench (provided) to eliminate stripping and deforming under load. $15
BRAKES AND LEVER For lightweight, stiff and precision performance, TRP’s Donny Robinson signature V-brakes are impossible to beat. They feature forged-aluminum arms for maximum power transfer and modulation and are fit with titanium pivot bushings and bolts to save weight. The kit is also available with a carbon fiber brake lever that weights a mere 2.8 ounces and is a perfect match for our performance needs. Kool Stop brake pads finish the set off nicely and meet our high, ready-to-ride standards. $99
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!0 -,$' #0 !-,!#.2 .#"*1 When it comes to rotating weight, people tend to only consider their wheels, but last we checked, your pedals go round and round as well. This is why we didnâ€™t hesitate to put a set of composite Time ATAC XS pedals on our project. Their ultralightweight composite body and minimalist trap system result in a finished weight of only 12.1 ounces, and that is with chromoly spindles. Cartridge bearings keep things turning smooth, dual-sided entry means quick recovery times if you come unclipped, and simple function means even mud wonâ€™t bog your clips down. They feature optional 13- or 17-degree release angles and have a standard 5 degrees of float. $149
12#+ Race stems are tricky because they need to be stiff, strong and offer plenty of reach, but at the same time, they canâ€™t be bogged down with the heavy materials that are required to meet these standards. Fortunately for us, Elevn worked some magic on their Barlok Pro TL stem to offer us the rise and reach of an XL top loader but with the strength and stiffness of a CNC-machined 6061 aluminum core. The end result is a 53mm-reach stem that only weighs 9 ounces thanks to a split cap and heavy machine work, making it a perfect match for our ride. $64
1#2 The perfect seat for the minimalist racer has to be the S-Spec D-Spyder saddle from Tioga. Now available in a pivotal version, it offers the same feathery shell, but now with a pivotal interface and lightweight aluminum hardware to secure it. Weighing only 6.7 ounces, it is a durable saddle and ideal for our needs. $34 68QQQ<GRJFOMG;A=IG
Our carbon concept build was so stiff and so light, it was tough to keep the front tire on the ground at times.
2,%#,2%0'.1 Throttle grip is not going to fly in the Olympic gate, so we didn’t even bother with conventional rubber. We chose a set of Tangent’s Lock-On grips, complete with a glove-friendly, waffle-pattern surface and soft flange, as well as lock rings and snap-on bar ends for added safety. Available in dozens of color combinations, their 130mm length helps keep the weight down while at the same time helped us maintain a professional look. $23
Handling such a light bike requires expert experience, and Joel Shuler had plenty of that to go around as he ran the bike through its tech-handling paces.
Many of the features on this bike are prototype or custom, and the cranks are a prime example. FSA is always pushing the envelope in product development, and the cranks on our carbon project are without a doubt the future, but unfortunately aren’t available for BMX applications outside of our custom kit just yet. The SL-K cranks are carbon fiber wrapped around an aluminum core for rigidity and strength and a weight conventional cranks can’t touch. Our cranks feature 175mm arms for a quick spin, and their two-piece design turns on a 24mm, hollow, aluminum spindle. This ultra-lightweight spindle is still being refined and tested for long-term BMX abuse. But not to leave you hanging, FSA makes a steel-spindle version of the same cranks, called the SL-K MegaExo cranks ($509), which are currently suited for the rigors of BMX and are actually being applied by several Elite riders. So if you can’t contain yourself, the MegaExos are the way to go. For those riders in search of a five-bolt option, FSA also offers the SLK Light Compact EVO386 cranks ($549) with hollow, monocoque, carbon fiber arms to keep you cranking. Estimated value of our custom cranks? $569. And since we are people of simple pleasures, the bottom bracket on this project is one of our favorite pieces of the puzzle. For about two years now, the best cranks in the business have been out of BMXer’s reach, because most performance models with the ultra-stiff, oversized spindles that BMXers want require a BB30 bottom bracket. Unfortunately, BMX bikes are predominately Euro, leaving riders to settle for smaller spindles and outboard Euro bearings, but FSA is about to change all of that. Their new MegaEvo bottom bracket conversion kit will convert a Euro bottom bracket shell to outboard BB30 bearings, which allows us to run trick cranks like our SL-Ks. But they didn’t stop there; they designed the BB kit with steel bearings for affordable performance at about $54, as well as a peak-performance ceramicbearing version. While the $224 price tag for this kit may seem heart-stopping, when performance is the name of the game, the low friction, high durability and low profile of ceramic bearings are impossible to work around.
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$0-,2&3 For Elite competition, we wanted a hub that was lightweight, minimalistic yet still had big enough bearings to handle a really hot lap. This is why we chose the Sun Light front hub. We chose the 36-hole version to meet our SX standards of durability, which features a streamlined 6061/T6 aluminum body, a hollow heat-treated chromoly 3/8-inch axle, precision-sealed bearings and 7075/T6 aluminum hardware. Clean, simple and, best of all, affordable. $79
The Envy rim from Sun has long been a standard for BMX racing, and now itâ€™s even lighter. The dual-wall alloy rim features riveted eyelets for durability and a precision true and is pinned to handle pro-level abuse without separating. So how did they make it lighter? They made is narrower. Now only 25mm wide, it is a great match for skinny tires and weighs only 330 grams. $39 each
0#0&3 The rear hub is actually included with the P79 frame, but suits the frameâ€™s high-performance design. The four-pawl cassette hub features a lightweight, aluminum, 36-hole shell and a trick, 15mm aluminum thru-axle designed specifically to interface with the closed dropouts of the frame. The design is 20 percent stiffer than a conventional 3/8-inch axle hub yet lighter, so itâ€™s a win-win.
When it comes to big weight savings in wheels, titanium spokes are impossible to pass up. Weighing half that of a steel spoke, USA Brand titanium spokes are made in the USA from American-mined titanium and are available in a variety of lengths and counts to suit any BMX build. USA Brand also offers a huge variety of colors, including the raw finish we chose for our wheels. Eighty-count set, $159. We chose to go with Wheel Smith alloy nipples on this project to keep the weight down as well as the headaches. Alloy nipples weigh half that of brass, but arenâ€™t nearly as easy to make, so we always like to go with a brand that has a long-standing reputation for quality. The last thing you want is to tag a jump and have all your spokes pull through the nipples when a gold medal is on the line. Two 50-count bags, $29.
0'"#2&# *'%&2,',% With so many prototype parts in the mix, we were worried that we might not get to ride the bike right away, but with a 15-pound Pro XL in your hands, how can you not? We decided to take it easy on the bike and get in a few light laps, but that was all that we needed for an eye-opening experience. Though built as a concept, it handled amazingly well and was lightning fast out of the gate. Touchy at first, the bikeâ€™s handling was effortless, making it as great a threat on the ground as it was skimming over it. The rigidity of the bike as a whole was unmatched on any bike we have ever built, ridden or tested. Every pedal stroke felt as though 100 percent of the power was making it to the rear wheel, and it made such a big difference on the gates, we actually had to slow our timing down a beat because the bike would go into motion that much faster. With such little rotating weight, the bike seemed to float down the straights, but thanks to the bite of the new Kenda Kompact tires, the bike would dig in and hold tight to any hardpacked track surface. In no time the riders became more comfortable with the bikeâ€™s 15-pound weight and began to compare them to their own bikes. One of our test riders had an 18-pound Pro complete and the other a 19.6-pound Pro XL, making this bike pounds lighter than their own custom-built bikes. While itâ€™s tough to establish a thorough opinion in a few short laps, both riders were considering using ideas from our carbon fiber bike project as a template to cut weight on their own rides. Were there details they just werenâ€™t comfortable with? Sure. Neither rider would be comfortable with the Bombshell bars for the long term, especially on the SX track. But for the one race that matters most, they are just what the doctor ordered. Both riders also agreed that they would go with a 1.95-inch version of the Kompact tire in the front for a little more steering contact, but keep the 1.75 inches in the rear. Beyond these details, they found the bike to be the pinnacle of performance. And as our prototype parts are updated to production, they look forward to joining us for a full-scale test. Be sure to join us for more on this 15-pound speedster next month as the tracks get bigger and we push this concept bike to its limits. â?‘
.0-(#!2 1,.1&-2 WEIGHT: 15.1 lb. PRICE: $3,290 RIDER WEIGHT: 200 lb. or less DESIGN GOAL: SX-worthy, functional, featherweight
ANSWER: www.answerbmx.com BOMBSHELL: www.bombshellparts.com FSA: www.fullspeedahead.com JAGWIRE: www.jagwireusa.com KENDA: www.kendausa.com KOOLSTOP: www.koolstop.com MAXXIS: www.maxxis.com REDLINE: www.redlinebicycles.com SPEEDLINE: www.speedlineparts.com SUN: www.sun-ringle.com SUPERCROSS: www.supercrossbmx.com TANGENT: www.tangentproducts.com TIME: www.time-sport.com TIOGA: www.tiogausa.com TRP: www.trpbrakes.com USA BRAND: Available through www.jrbicycles.com WHEEL SMITH: www.wheelsmith.com
Elite Women rider Ashley Verhagen takes our 15-pound project bike for a trial run to see if itâ€™s up to SX-caliber snuff. june 2012