Article first featured on www.bikerumor.com on June 25, 2012
Neilpryde just launched two new bikes, the Bura SL and Bayamo.
The Bura SL is a new pro-level road racing bike developed with feedback from the United Healthcare team. Where the new Bayamo and their previous models, the Diablo and Alize (reviewed here), were designed in conjunction with BMW, the Bura SL was designed in house. The goal was a sub-750g frame that was stiff enough for competition yet comfortable enough for sportive riders.
Other criteria were to be Di2 compatible, have a fork that was stiff enough for sprinters and without beating up the rider.
So, stiffness, comfort and lightweight were the three priorities, aerodynamics were left to the Alize, and the Diablo remains the stiffest bike, aimed at sprinters.
Claimed fork weight is 308g, bare frame weight is 740g. Add hardware (BB guide, hanger, bolts) and the complete frame is 772g. That pus the frameset at 1080g. They benchmarked that against the Cervelo R5 and came out 8g lighter for the total frameset and claims to have better stiffness where it counts yet with better fore/aft flex for comfort.
There are two frame models, a standard mechanical frame and a Bura SL Di2 that comes in at 760g. The holes drilled for Di2 wiring need to be reinforced, which adds a few grams.
Where many builders use a silicone mandrel to form the tune junctions, Neilpryde uses polystyrene molds that are then burned out. They claim this allows more accurate wall thicknesses, and they place a layer of 3K carbon on the inside for additional stiffness.
This combines with the angular, ribbed headtube junction and squared off top tube to maximize steering stiffness and torsional rigidity when you’re cranking side to side.
There’s a PFBB30 bottom bracket with an asymmetric seat tube to allow proper placement of the front derailleur.
The chainstays are massive and designed with continuous fibers from where they meet the BB all the way through the dropouts and into the seatstays. This creates both stronger and lighter dropouts. Mike Pryde, bike division manager, says the bike can be ridden without the seatstays, that the chainstays are that strong.
The seatstays are at the UCI minimum 10mm diameter. They’re combined with this new single-bolt 27.2 seatpost to provide a fairly compliant ride.
For the Di2 model, the battery was placed just below the lower water bottle mount, which uses the battery mount kit that bolts to the water bottle bosses. They say this saves a bit of weight versus adding metal inserts for battery mounting under the chainstay.
Six sizes are offered, XS through XXL, with top tubes ranging from just 510mm up to 595mm. Retail is $4,250 for the frameset (includes headset, seatpost and carbon clamp). Complete bike pricing is TBD.
2013 NEILPRYDE BAYAMO TRIATHLON / TIME TRIAL BIKE
The Bayamo was first spotted at Interbike as a prototype and is designed to offer the dual package of aerodynamics and stiffness. Comfort wasn’t as much of a consideration as with the Bura SL because, in most cases, triathletes and time trialists are on fairly smooth pavement.
Two models will be offered, a standard Bayamo (shown) and a more integrated Bayamo Plus. It was designed in conjunction with BMW and Alumni Design. BMW provided the industrial design and styling, using their own knowledge of aerodynamics. Throughout that process, Alumni’s Kevin Quan (a prior employee of Cervelo that worked on the P3 bike) fine tuned it using a unique take on the Kamm Tail design.
For aerodynamics, they wanted it to be fast and stable with crosswinds up to 15°. To create a fast and stiff bike, they benchmarked it against the Cervelo P3 and Trek Speed Concept.
Bike division manager Mike Pryde says the shape alone of the Bayamo does a lot to provide better stiffness numbers than those two bikes. Their Kammtail airfoil downtube claims to be stiffer thanks to its wider 30mm cross section (compared to 26.7mm on the P3 and 27mm on the Trek – their measurements, not ours).
Besides width, the other differentiator is the actual Kammtail shape. Where most people think of the Kammtail as a flat slice through a teardrop shape, it actually refers to any truncated teardrop shape. The Bayamo ‘s trailing edge still goes to a point, but the point gets flatter as it nears the bottom bracket. This has two benefits: first, it keeps the bottom bracket stiffer because it’s more of a box section tube shape there. Second, it creates a more aerodynamic tube shape when the wind has a higher yaw angle (ie., bigger crosswinds). Diagram above is a rough representation of the trailing edge of the tube at various points.
The lower bottle mount has three bolts, letting you run one single bottle in a lower position or two bottle in their regular positions with one on the seat tube.
From there, they improved it further by giving the seat tube a Kammtail trailing edge that carries through to the seatstays. The back of the fork legs uses the same flat shape. They used CFD to optimize the shapes of each tube.
On the standard Bayamo, cables enter the headtube directly behind the stem, and all cables run full length housing with internal retainer to keep it from rattling. This lets you replace just the cable very easily.
Development was driven by the UHC team, and it has UCI approval, but it’ll also be their triathlon offering. In working with the United Healthcare riders, one of the surprising requests was to improve braking performance. Riders said they wanted to be able to brake as late as possible, then accelerate hard out of the corners.
The frame weight is 1300g bare, and 1332g with hanger, bolts and BB guide. Fork is 308g, complete frameset is 1640g. Five sizes will be offered, S through XL, with top tubes from 469mm to 565mm. Retail is $3,250 for the standard frameset. Theyll ship in August in S, M and L, with other sizes following soon.
The Bayamo Plus gets several upgrades. The front brakes are TRP and integrated into the back of the fork legs. Rice says using an existing brake model makes replacements and maintenance far easier.
There’s a patented adjustable stem that has both angle and length adjustment. It uses side plates with holes drilled at center, +/-5mm and +/-10mm, giving it an effective 20mm of range adjustment. The stem base will be in different lengths based on frame size, with options for people with unusual body proportions. The angle of adjustment is huge, virtually from straight down to straight up.
The firm has an integrated nose cone that sits in front of the head tube and is built into the stem’s base. This front end, including the fork, front brake and stem, could be added to the standard Bayamo anytime.
A TRP rear brake is integrated under the chainstays with a removable service port cover just in front of it. It has a brake plate for the rear brake, which makes removal quicker and easier. Cable stop covers are also removable for easier installation.
Both frames are Di2 compatible with small wiring ports and battery mounts under the chainstay, further back from the brake.
Look for the Plus to be up around $5,500 and probably available in November.
Left to right:
- Bura SL Dura-Ace 7900 – 13lbs 4oz
- Bura SL Ultegra Di2, ENVE/DT wheels – 13lbs 14oz
- Bayamo Dura-Ace 7900, Mavic Cosmic CXR 80 – 17lbs 7oz