Road Gear

Mercury M-3 carbon clincher wheels — Impressive, once you manage to get tires on them.

Nick Legan puts a pair of Mercury carbon clinchers to the test.

Mercury M-3 carbon clincher wheel review
Mercury's wheels never came out of true, even on dirt roads.

Carbon clinchers wheels have typically disappointed us in the VeloNews tech department. For the March issue of VeloNews we have an in-depth test of six carbon clincher wheelsets. Mercury’s wheels didn’t show in time for that test and I wasn’t able to test them in the same manner as we did the other six pairs. But that doesn’t mean that I wasn’t mostly impressed. The only downfall was trying to mount up tires to take them for a ride.

I had never heard of Mercury Wheels until they reached out to me for a test. I checked out their web site and was interested. As you would expect, Mercury Wheels is not a big player in the carbon wheel market. Based in Mississippi, and founded three years ago, Mercury started with consumer direct sales. In early 2010 Mercury decided to seek out bike shop dealers as well.

VeloNews got its hands on a pair of pre-production M-3 Carbon Clincher wheels for a week’s worth of testing. We have to say, while the price tag is a bit high, we were mostly impressed with Mercury’s 39-millimeter deep wheels, which retail for $2199. The biggest problem was simply installing tires.

A mid-depth aero wheel is extremely versatile. Even in stiff Colorado Front Range winds, the Mercury wheels were stable. The ride quality of the wheels is excellent. They are not as vertically rigid as many other carbon wheels. This is a real plus for smaller riders. Larger riders may want to check out Mercury’s deeper section wheels for a more rigid option.

Over rough and even dirt roads the wheels performed flawlessly and never came out of true. A good thing too, as the hidden nipples make adjustments a bit of a pain. I mentioned this to their product manager and 2011 production models will have external nipples.

VeloNews March 2011 issue: Carbon clincher review
The March magazine features an in-depth carbon clincher review

The braking surface is consistent, even if overall braking power is not exceptional with the supplied brake pads. Unfortunately, I didn’t have time to try other brake pads on the wheels. The braking surface is very consistent and this goes a long way in carbon rim braking performance. Over the course of my test, the braking did improve. I suspect that the pads rough up the rim just a bit, possibly clearing off any mold releases or glazes. It could also be that a bit of brake pad embedded in the rim and that helped the situation. In all, the rims’ tolerances were good.

Mercury laces their rims to White Industries hubs and, even after all these years, White Industies still puts out a good hub. The bearings spin smoothly and the freehub body doesn’t produce the loud, sometimes annoying, noise of a Chris King hub.

The wheels I tested are 100 grams heavier per rim than Mercury anticipated and future wheels are expected to be lighter. 100 grams is a lot but I must say, maybe somewhat controversially, that I enjoyed the slightly higher mass of these wheels. Uber light wheels can feel dangerously unstable, especially during high-speed descents. There’s a lot to be said for predictability and stability. At 630 and 790 grams for the front and rear wheels (with rim strips), the Mercury are by no means heavy though. If Mercury is able to take 200 grams off their current 1420-gram weight, I’ll be impressed. For comparison a pair of Easton EC90 56mm carbon clinchers with rim strips weigh in at 1,750.

The toughest part in riding the M3 wheels was simply installing Continental GP4000 tires. The pair I used had been previously installed on Bontrager Aeolus 5.0 carbon clinchers. I had zero problem installing and taking them off the Bontragers.

Mercury M-3 carbon clincher wheel review
White Industries rear hub works well without the noise of other popular brands. Two-cross lacing on the rear wheel makes sense.

The internal diameter of the rim must have been slightly oversized. The rimstrip Mercury provided was no thicker than any other normal strip. As a pre-production wheel, this can be excused, but bear it in mind if you check them out in a bike shop.

Mercury also offers a tubular version of the M3 for $2,000 a pair. If spending over two grand isn’t in your budget, Mercury has its S series, which use Mercury-branded Novatec hubs instead of White Industries and DT spokes instead of the Sapim spokes. The S3 tubular is $1,300.

In all the Mercury M3s are nice carbon clinchers. The 39-millimeter rim depth is versatile and the light weight and good braking surface make the Mercury’s a pleasure to ride. Just try tires on them before you pull the trigger on buying a pair.