Every once in a while, a product comes along that seriously intrigues us by rolling far outside the cycling industry thinking norm, and creating something that is seriously new.
Based in Adelaide, Australia, Bouwmeester Composites is designing and producing carbon composite products by hand in Australia. They say their local manufacturing is critical to the performance of their end products because they can have 100% control over the technology and quality of the manufacturing process for the finished product.
The Bouwmeester Composites Tammar V4.8 carbon fiber rims excite us with their combination of new ideas while advancing current trends. The idea of a wide rim is pretty hot right now in both road and mountain. The 27.5″ wheel is pretty established for “enduro”, and single-walled carbon fiber rims are already pioneered by several companies for fat bike rims. However, it’s Bouwmeester’s combination of the two (and their reasons for doing so) that make us really wanna get on a pair to see how they ride…
Starting out, Bouwmeester reminds us that current double-walled rim designs are carried over from traditional aluminum rims. A hollow box structure like a double-walled rim is the best way to get the most stiffness out of a metal structure with the least amount of material. This has been carried into carbon rims simply because it is the general thinking of the cycling industry. But, composite rims do not necessarily have to follow those laws since changes in the material, fiber orientation and thicknesses in specific areas can be tuned in composites, but not so easily in metal structures. The rim is a solid profile, similar to motocross rims, which from a carbon engineering perspective means the fibers are supported correctly through an optimised laminate. This means the rim loses the weight of a 2nd wall, but Bouwmeester departs from what the fat bike rim makers are doing, and uses that material to thicken up the overall rim, rather than save weight. This makes for a super tough sidewall.
A single wall rim also allows them to mold in the nipple seats, similar to a motorcycle rim, which optimizes them for the specific spoke angle of each nipple. In a double-walled construction, there is typically a spoke tension limit because they are trying to keep both walls as thin as possible to keep the weight down. By combining both walls into one on the Bouwmeester rims, the nipple seat is much thicker and stronger than normal, and there is no spoke tension limit on these rims. With a single-wall profile, Bouwmeester also claims they can make a front or rear optimized layup for the needs of each end of the bike.
Finally, a hook-less bead profile combined with the wide platform supports a rounder tire profile to improve the handling and performance of the rim. This is pretty common amongst newer rims though, and at 38mm wide, are similar to the Ibis 741 rims. This width, combined with the hook-less profile and the thickness of the sidewalls is why Bouwmeester claims they have superior impact resistance to other rims on the market.
Can a single-walled carbon fiber rim designed like a motocross rim be stronger than the current crop of composite rim designs on the market? Check out our long term review to see how they performed in the real world.
SPECS:
- Profile – Tammar 27.5” V4.8. Asymmetric.
- Material – Solid carbon fiber rim. Optimised Modulus Fibers.
- Nipple holes – Head recess molded to suit spoke angle. Drilled spoke holes for max strength with no spoke tension limit.
- Spoke count – 32 hole
- Width – 38mm
- Inner Width – 31.5mm
- Depth –12.5mm (15.5mm to tip of nipple mounds)
- Hubset – DTswiss 240
- Rim Weight – 485g
- Wheelset weight – 1,780g
- Price – $2,999 AUD
