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Back when we started building our first bikes in the late 70’s, steel was the only way to go. Fast forward 35 years and steel is no longer the industry’s dominant frame material, but we still love to work with it and ride it. Why? Hit a baseball with a wooden bat then with an aluminum bat and you’ll know why. You want your frame material to soak up streets and trails, not beat you with them. Not to mention the stuff is durable, can handle nicks and dents and gouges without cause for alarm, and is easily repairable. We like the look of those straight, skinny tubes, too.
Reynolds pioneered the techniques of making butted tubing around the turn of the century, and their 531 manganese-molybdenum tubing was the standard of excellence for many decades. In 1995, Reynolds introduced 853 (and a non-heat-treated version, 631, two years later); the world’s first commercial air-hardening steel for bicycle frames and Jamis was one of the first brands to use it in 1997. Welding steel often results in a 40% strength loss, requiring thick tubing walls as an offset. Not so with 853 and 631. This material actually gets stronger at the weld zones, allowing Reynolds to draw the tubing thinner for a lighter, stronger frame.
Though the high performance and buttery-smooth ride qualities of Reynolds 853 and 631 usually grab all the headlines, our frame building is equally over the top. All tubing is cleaned before being cut, jigged and welded. All tubing cuts are de-burred and buffed before welding. We use heat sinks in the head and seat tubes to control distortion. And our low-angle welding tracks form precisely arced, low-profile TIG beads while dispersing welding heat more widely, yielding a frame that requires less post-welding alignment. Add investment cast or water-jet cut dropouts for great looks and extra strength and you’ve got a labor of love that rides like a dream.
Boost 148 moves the rear hub flanges 3mm outboard on each side in order to improve the spoke bracing angle. The spoke bracing angle is the angle formed between the spoke and the vertical plane. By moving the hub flanges outwards, spoke angles increase, creating a more stable base. Larger spoke angles are able to balance a larger component of the lateral forces exerted in the horizontal plane during loading. So, with a wider hub shell comes better bracing angles of the spokes, which results in a stiffer, stronger wheel.
With these minor shifts in flange spacing, the brake rotor mount and the freehub body location have to be taken into consideration and boost bikes compensate with adjustments to the chainring position. In order to get the best shifting performance, with the cassette 3mm outboard, the chainline (the line from the chainring to the center of the cassette) needs to be moved to accommodate that new position. It is necessary to move the chainrings outboard by 3mm and this shift can be accomplished with a redesigned crank arm spider. The crank arm Q factor (the distance between a rider’s feet when they’re on the pedals) and the frame’s bottom bracket shell width remain the same. With the chainline shift outwards, the frame is afforded more tire and chainring clearance and can maintain short chainstays.
A 3” tire, when paired with a 26” or 27.5” rim size, results in an overall outside diameter of the standard version of the next larger mountain bike wheel size. In general, a 27.5 rim with standard 2.2”-2.3” tires results in an overall outside diameter of 27½ inches. 26 Plus is achieving this same overall outside diameter of 27½ inches by downsizing to a 26” rim but pairing it with a 3” tire. Same when looking at 27.5 Plus. A 27.5 rim paired with a 3” tire results in approximately a standard 29er outside diameter.
Larger volume tires on wider rims allow for lower air pressures to be used , especially when set up tubeless, resulting in a larger contact patch with the terrain. Having more knobbies on the ground results in more traction and additionally provides the ability to float easier over rocks and roots. By outfitting our 27.5 and 29er trail hardtails with 3” tires, inexperienced riders benefit from the increased stability, float and traction. At the same time, more traction allows seasoned riders to ride terrain even faster and with greater confidence.
All our frames and forks are tested continually to meet or exceed (in some cases, well exceed) EN standards 14764, 14765, 14766 and 14781 as well as the new ISO 4210 standards. We conduct these tests at our frame manufacturing facilities, but we also use EN accredited testing laboratories such as Intertek and SGS to verify the results of our own tests. If these tests aren’t telling us everything we want to know about our bikes, we increase the loads and cycles, or we determine another way to test. Where current hydraulic testing machines, jigs and hardware aren’t up to the task of emulating some of the forces and impacts our bikes might be subject to, we’ve designed our own.
We relentlessly cycle test for fatigue from pedaling and torsional forces on every single frame size, with deflection tests for stiffness at every point of the frame. Brutal impact tests with massive weights dropped on fixed frames or forks are performed. Then reversed, with weights attached to the frame, the frame hoisted to a given height depending upon product type, then released.
This destructive testing is enormously instructive and important. And it is in continual process. But it’s our ongoing non-destructive testing of frames and forks fresh off the factory floor that’s just as vital.
For our carbon fiber frames, EVERY frame is weighed to make sure it’s neither resin rich nor resin deficient. We also measure the stiffness of each frame in 6 critical areas as a check on lay-up production. Each deflection test must fall within 5% of the standards our machine and field-testing have established. This weighing and stiffness deflection testing guarantees every single frame we produce meets all Jamis manufacturing protocol and will
deliver the ride qualities we defined and demand.
A 27.5x3” tire measures out to a 29” diameter and a 26x3” tire measures out to a 27.5” diameter. Combining them with a 40mm rim, results in the ultimate combination of traction, roll-over and versatility without being too heavy, too bouncy, too tall or feeling lethargic on the trail.
For well over a century, Reynolds has been at the forefront of cycling design and engineering continually pushing the boundaries of performance. The 520 series double-butting provides both strength and weight savings resulting in a smooth riding frameset.
Oversized 44mm head tubes, like tapered head tubes, offer many advantages impacting the handling and performance of the bike. Not only do they allow for the use of tapered steerer forks adding more stiffness, lighter weight and better tracking in rough terrain, but the larger diameter provides a better surface area to weld the main triangle tubes to.
Our sliding dropout allows for 15mm of adjustment. Slide your rear wheel back to increase clearance for larger tires or remove all those gears and shifters and simply tension your chain for a quiet single speed ride.
The Dragonslayer and Dragonfly frames feature rear rack eyelets and enough cargo/water cage mounts for the option to load up all the gear you may possibly need out there. Full cable housing guides are used to ensure uninterrupted shifting performance when using a frame bag.
A 12x148 rear hub with 3mm offset chainrings minimizes the chance of chain to tire contact with short chainstays and “mid-fat” tires without compromising any pedaling efficiency to a wider q-factor.
Benefits of a tubeless set-up are reduced rotating weight and the ability to use lower inflation pressures for greater traction without the risk of pinch flats. WTB TCS rims feature a tubeless UST “On-Ramp” profile providing a consistent fit between the rim and the tire for easy installation and inflation.
UPGRADES FROM DRAGONSLAYER 27.5+ SPORT
• Fox Rhythm 34 fork
• 12-speed drivetrain
• Shimano SLX brakes
• KS dropper seatpost
CHANGES / UPGRADES FROM Previous Model
SRAM GX Eagle 12-speed drivetrain
• Vittoria Cannoli tires
|Frame||Reynolds 520 steel, 44mm head tube, 31.6 I.D. seat tube, internal dropper post routing, ISCG05, sliding 12x148mm dropouts, Formula thru-axle|
|Fork||Fox Rhythm 34 Float 29/27.5+ w/ sweep adjust compression & lock-out,15x110mm axle, air spring compression, rebound adjust, tapered alloy steerer, 120mm travel|
|Headset||FSA Orbit, Alloy cups|
|Wheels||WTB Scraper i40 TCS tubeless 27.5" rims, Formula sealed bearing 15x110mm front & 12x148mm rear 6-bolt disc hubs, stainless spokes|
|Tires||Vittoria Cannoli, 27.5 x 3.0”, TNT tubeless|
|Derailleurs||SRAM GX Eagle, 12-speed|
|Shift levers||SRAM GX Eagle, 1x12-speed|
|Chain||SRAM GX Eagle, 12-speed|
|Cassette||SRAM XG-1275, 12-speed, 10-50T|
|Crankset||Truvativ Stylo, 32T, 170mm (15"), 175mm (17-21")|
|BB Set||SRAM GXP|
|Brakeset||Shimano SLX hydraulic disc,180mm front & 160mm rear RT66 6-bolt rotors|
|Handlebar||Ritchey Trail, 710mm x 20mm rise|
|Stem||Ritchey Trail, 60mm (15”), 70mm (17”), 80mm (19"), 90mm (21”)|
|Seat Post||KS eTen Integra, 100mm travel, Southpaw remote|
|Saddle||WTB Volt Comp|
|Sizes||15”, 17”, 19”, 21”|
|SIZE||TOP EFFECTIVE||HEAD ANGLE||SEAT ANGLE||CHAIN STAY||WHEEL BASE||BB DROP||HEAD TUBE||STANDOVER||STACK||REACH|
|15||22.8 / 580||68˚||73˚||17.1 / 435||43.5 / 1104||1.9 / 47||3.7 / 95||30.4 / 773||24.4 / 621||15.4 / 390|
|17||23.6 / 600||68˚||73˚||17.1 / 435||44.5 / 1130||1.9 / 47||3.9 / 100||31.7 / 806||24.6 / 626||16.0 / 408|
|19||24.4 / 620||68˚||73˚||17.1 / 435||45.3 / 1151||1.9 / 47||4.3 / 110||33.0 / 840||25.0 / 635||16.7 / 426|
|21||25.2 / 640||68˚||73˚||17.1 / 435||46.2 / 1173||1.9 / 47||5.1 / 130||34.5 / 876||25.7 / 653||17.3 / 440|
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FIT & SIZING
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Specifications are subject to change without notice.
All bike and frame weights are based off pre-production painted frames. Weights may vary in final production.
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