Disc-equipped sub-kilo carbon cyclo-cross racer launched

Hot on the heels of the the RLT 9 cyclo-cross we showed you recently, US company Niner have pulled the wraps off their new Blood, Sweat and Beers carbon fibre cyclo-cross model.

Race-ready carbon frame

Unlike the RLT 9 which features an aluminium frame, the new Blood, Sweat and Beers (or BSB9 for short) gets a claimed sub-kilo carbon fibre frame. Niner have no qualms in calling this a race bike, with race-ready geometry and a ‘no-compromise stiffness, strength and ride quality’ from the carbon frame and fork. The paint has even been used sparingly to save an extra 50g of weight, with thin decals and a satin clearcoat protective layer.

Like the RLT 9, it has been designed specifically for disc brakes, and accepts up to 160mm rotors at both ends. The rear wheel space is 135mm, rapidly becoming standard on all the latest disc-equipped road and cyclo-cross bikes, and it uses quick release rear axle and 15mm bolt-thru front axle. The frame and fork have a quoted tyre clearance of 40mm.

Further evidence the BSB9 has been designed for the demands of cyclo-cross racing are the oversized tube profiles. The down tube and chainstays are on the large side to ensure maximum power transfer, taking some influence from their carbon fibre mountain bikes for which they’re better known.  A tapered head tube (1.125in-1.5in)  takes Niner’s new RDO Cyclocross fork. A 63mm wide press-fit bottom bracket shell is used to beef it up in that area. The seat tube takes a 27.2mm post, to allow for as much deflection as possible to provide a smidgen of comfort.

There’s an absence of cable guides inside the front triangle, the rear brake routed along the side of the down tube and internally routed gear cables, with full-length housing to prevent the ingress of dirt and water. The frame is fully Di2 compatible and designed with the internal seatpost battery in mind.

The frame is constructed using Niner’s Carbon Compaction System. This amounts to the use of rigid internal moulds which they claim results in a "tighter and more consistent compaction of the carbon fibre" when it’s being constructed, leading to greater precision in wall thickness. Claimed frame weight for a size 56cm is sub-1kg, they don’t quite an actual weight figure. The frame is available in six sizes, 47, 50, 53, 56, 59, 62 cm, and each has two water bottle mounts.

The geometry pegs the bike cleanly into cyclo-cross race territory. A 565mm effective top tube on the 56cm model with 425mm chainstays, 1028mm wheelbase, 155m head tube and a 72 degree head angle and 73.5 degree seat angle. Reach is 393mm and stack is 582mm. The bottom bracket drop is 65mm, not as low as some cyclo-cross race bikes but should provide plenty of pedal clearance over rough and bumpy terrain. The geometry is size-specific with varying bottom bracket drops and crank length across the size range.

Bolt-thru front axle, quick release rear

There’s a lot of discussion about the merits of bolt-thru axle technology (which use large diameter hollow axles that thread into a closed axle) in the road market at the moment. Niner says they chose the bolt-thru front axle because there were “significant advantages in stiffness and steering,” yet stuck with a traditional quick release axle at the back because “there was no noticeable improvement in rear stiffness between the QR or Maxle option."

Niner are not alone in speccing a bolt-thru front/quick release rear setup, many other brands are using the same approach too, such as Giant with their TCx. It does seem likely that we’ll see the market split between full bolt-thru setups, like the Storck TIX, and a mix of bolt-thru front and quick release rear. Some manufacturers clearly have a preference from an engineering point of view, but which you choose if you’re a racer with lots of wheels could be problematic.

Much of the axle preference issue can easily be taken care of with wheels with changeable axle end caps, such as those largely popular in the mountain bike world, which would avoid having to buy new wheels should you upgrade to a frame with different axles.

Post mounts are used front and rear, with the rear placed inside the rear triangle and positioned to maximise heel clearance.

Race intentions

Where the RLT 9 is designed as a versatile do-everything cyclo-cross bike, with a longer wheelbase, slacker head angle and lower bottom bracket, bigger tyre clearance and rack and mudguard mounts, the new BSB9 is an out-and-out race bike with sharper handling from more aggressive geometry and a stiff frame and no rack or mudguard mounts. It’s purely for racing, or riding very fast around the woods.

The bike is currently being raced by Team CLIF who were spotted putting the new bike through its paces ahead of the official unveiling. 

BSB 9 RDO Bike Check from Niner Bikes on Vimeo.

No word on pricing or availability just yet. More info at www.ninerbikes.com/BSB9RDO

David has worked on the road.cc tech team since July 2012. Previously he was editor of Bikemagic.com and before that staff writer at RCUK. He's a seasoned cyclist of all disciplines, from road to mountain biking, touring to cyclo-cross, he only wishes he had time to ride them all. He's mildly competitive, though he'll never admit it, and is a frequent road racer but is too lazy to do really well. He currently resides in the Cotswolds.