Bouwmeester Wheels

Carbon MTB rims aren’t just for weight obsessed XC racers. The use of carbon has allowed manufacturers to create wider trail oriented rims without incurring a huge weight penalty. Wide rims support the tyre better, allowing the use of very low air pressures without tyre squirm and burping issues. With a 31.5mm inner width, the Tammar rim is suitably wide, but there’s a lot more going on with this rim design.

Most carbon rims mimic modern alloy rim with a box shaped cross-section. In this case, Bouwmeester decided that a single-walled design was more appropriate for composite construction and the Tammar looks more like an old steel BMX rim.

Wide box section rims promote stiffness – something that’s generally seen as a good thing – but ultimately this rigidity can make the structure more prone to catastrophic failure if you hit something hard enough. Box section rims also have thin walls, which can be more vulnerable to impact damage. The material in the Tammar is much thicker, which adds impact resistance and also places more carbon around the spoke holes.

Along with the unique cross-section, the carbon layup is said to produce an ‘optimum balance of torsional stiffness’. I’ve built and ridden plenty of carbon wheels – from big-dollar Enves to unbranded Chinese rims – and all have been exceptionally stiff. I expected the Tammar to be similar, but this certainly wasn’t the case.

Give & Take
Before mounting up the Bouwmeester wheels, I did a quick side-by-side check with my own wide carbon wheels. Laying each wheel on its side and pushing down on the rim revealed a noticeable amount of lateral flex—my own wheels felt unbelievably stiff by comparison. Even pushing down firmly on one side of the rim revealed a visible amount of give in the rim cross section. Initially I found it disconcerting; surely stiffer wheels are better, right? Well that’s what most of the marketing tells us.

I mounted them to my 160mm travel trail/enduro bike and the flex that I noticed when setting up the wheels never really reared its head on the trail. I’d expected them to feel imprecise or introduce some odd handling characteristics but they didn’t. One thing I did pick up on was the smoother ride. I was surprised that I could feel this when the bike already had 160mm of vertical ‘give’. It seems the localised rim flex takes the edge off the bumps that you don’t hit square on; the ones that usually throw you off-line when barrelling through a rock littered trail. The ride also seems ‘quieter’ than with large box section carbon rims; it’s as if they cut out some of the vibration and background noise and allow you to focus better on your line selection and the bigger obstacles.

No product is perfect of course and the Tammar rims have their own set of quirks. First up they are pricy; at $2,999 with DT 240 hubs they cost less than Enve wheels but not by much. At 1,839g for the pair (including tubeless tape) they are around 200g heavier than most other high-end wide carbon all-mountain wheels.

We had to true them once as they’d gone out by about 3mm. Land sideways from a jump and the lateral deflection within the rim transfers more load through to the spokes. As a result they may need more regular attention than wheels that use stiffer rims. At least they were very easy to work on, with 32 DT Competition spokes per wheel.

The freehub runs an 18-point DT Star Ratchet mechanism. We feel the 36-point ratchet wouldW have been more appropriate, giving quicker pedalling response in technical terrain. If this concerns you, Bouwmeester also offers their wheels built with Chis King hubs, and they have 72 engagement points per revolution (but they will make the wheels heavier again).

Finally, the supplied rim tape is thin and quite flimsy. Replacing the tape is fiddly too; a rubber bung covers the head of each spoke nipple, and these need to be held in place while you wrap the tape around—it’s almost a two person job. Choosing a more durable tape would save hassles all round; even some duct tape from the local hardware store would have done a better job.

None of these points are deal breakers; 36-point DT Star Ratchets are readily available and the tape issue isn’t hard to solve, but we can’t help feeling that these details should’ve been sorted from the outset on a $2,999 wheel set. Glitches aside, the Bouwmeester wheels are unique, truly Aussie made and offer a noticeable improvement in ride quality that seemed to enhance control when ploughing through the rocks.

Bouwmeester Composites www.bouwmeester.com.au