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.


  • 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




  1. Will this mean better vertical compliance without reducing lateral stiffness? That, and improved impact resistance, make for an intriguing idea.

    The pricing (~$2,500 USD) seems high for something with more straightforward manufacturing than box-section rims, though- even for something make in the first world.

  2. I’d say the price is more than justified:

    1) They are first with an innovative new design rather than simply aping existing designs.

    2) Despite using less material, it sounds like the manufacture is more time/labor intensive, especially considering the rear is different than the front.

    3) They aren’t producing these in volume (yet).

    Kudos to innovation, hopefully this design delivers.

  3. “With that profile, little worried about getting tight tires fitted, with no dish in the rim.”

    No kidding, and indicative of these people not knowing what they are doing. The bar is low for “technical innovation” in cycling. Given enough time, these guys will invent the box section.

  4. Yes clever, but I find it kind of disconcerting that Carbon rims are constantly coming out heavier than aluminum rims used to be. Part of it is the stupid transition to 650b but still a 485 gram rim was considered an anchor using aluminum. Strange what $2500 buys you.

  5. Considering the weight, and another Aussie company, Zelvy Carbon does a 40mm enduro rim at 400g. I would genuinely like to know the advantage in real terms.. great to see these guys doing rims though. Exceptional challenge in itself!

  6. @tim A: I think that much of the “vertical compliance, lateral stiffness” is a bunch of bullsh!t unless we’re talking full suspension bikes.

    I just want a stiff as hell, tough as hell rim. Don’t let it be compliant to anything. The tires, the frame should do the complying. The rim should keep the bead on like GRRRRRR and track true.

    Merry Christmas btw! (no sarcasm intended)

  7. Strange that they don’t mention how making them single wall and hookless will make them enormously easier to make… Yet I suspect that that is the main reason for the design choice…

  8. @dodo. i’ll take a little extra weight in a smartly designed carbon enduro wheel, than eat sh@! because my weight weenie mountain wheel failed at speed. just a thought…

  9. “I find it kind of disconcerting that Carbon rims are constantly coming out heavier than aluminum rims used to be”

    But there are plenty of light XC race rims that are super light… (Stans Valors, Enve M50, less interesting Specialized, Bontrager, etc stuff).

    I think the media has focused mostly on Enduro class carbon rims lately, which are indeed not super light.

  10. If this design allows the rim to be thicker and take hard impacts, then it may actually be a game changer. I’m sick of constantly denting alloy rims like the FlowEx and I’m afraid that the current crop of thin walled carbon rims will just crack. Carbon is undeniably stronger, so of it it can be made thick enough it should easily be able to take impacts without breaking.

  11. kappius kh-1 rear hub, king, hadley or dt 240 front hub, these rims = my ultimate wheelset, i will be saving for some time but these are the wheels i want!!!!!!!

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