Review: Fulcrum's Metal Carbon Wheels are Quiet, Fast, and Fuss-Free

By MTBSA contributor

Fulcrum has a strong history making high performance road wheels, but their name probably wouldn't come to mind when it comes to our fat-tired neck of the woods. They're looking to change that with a new mountain bike focused lineup, featuring carbon and alloy wheels alike - dubbed the Metal Carbon and Metal ALX, respectively. Confusing naming conventions aside, both wheelsets use Fulcrum's cup and cone hubs, and feature some unique build elements to set them apart. I've been testing the Metal Carbons, which are positioned as a fast trail bike wheel for general use.

Metal Carbon Details

• Carbon rims

• 29" only

• 24h front, 28h rear

• 32mm internal width

• Undrilled rim bed

• Weight | Claimed: 1550g, Actual: 1573g

• Boost axle spacing

• Price: EUR € 1,640

• fulcrumwheels.com

The Metal Carbon wheels are build with steel straight pull spokes and aluminium nipples, and feature an undrilled rim bed that does not require tubeless taping.

Despite the wonderfully confusing name, these rims are 100% carbon fibre, and contain no metal. As to how they landed on Metal Carbon for the name, I don't know, but I do love a good oxymoron so I'll let it slide.

MTBSA's Take

| Though Fulcrum might not be the first name you think of when considering a new mountain bike wheelset, I'd recommend taking a look at the Metal Carbons. There are some unusual details, but the key elements are well considered. They're quiet, surprisingly easy to live with, and felt perfectly suited to short travel trail bikes, where the balance of weight, durability, and ride feel is a tricky thing to get right. — MTBSA contributor

Fulcrum is one of the few brands still offering cup and cone hubs for their high end wheelsets, touting the durability and serviceability the system offers as an advantage over cartridge bearing systems. The ability to adjust preload on the system is another potential benefit, but that does come with the frustration of trying to get that load perfectly dialed - a delicate dance familiar to anyone who's spent time working on older hubs.

Fulcrum's design uses relatively few parts, and should be easy to service when it comes time to do so. The end caps can be tightened down to maintain a given tension, so there shouldn't be much change in the preload from riding forces.

There is no specific figure given for the hubs' points of engagement, but my count puts it at 36 detents per rotation, giving the hubs 10° of free play between engagement points. Not the highest engagement, but plenty for me and a typical amount for hubs using a traditional 3 pawl system.

The hub design is only available with a Centerlock brake mount, so 6-bolt fans will need to look elsewhere. Interestingly, Fulcrum went with a Campagnolo-style Centerlock mount, in which the threads are external on the hub, with female threads on the lockring. A standard tool works just fine, but finding aftermarket lockrings is a little bit trickier than the standard design.

The rims have some unique shaping to them, but are ultimately fairly standard. They're slightly asymmetrical, with a deep centre channel that makes fitting tight-bead tyres a breeze. The lack of spoke holes in the rim makes tyre swaps a stress-free process for those that are prone to tearing tape, though it may add some stress when you have to replace a broken spoke. The aluminium nipples are housed within the rim, and guided to their respective holes using magnets - Fulcrum calls this technology MoMag. There's a little instruction cartoon for reference, but in practice all you have to do is thread a small section of steel spoke into a nipple, then use a magnet to guide it to the desired hole. A bit more faff for the initial build, but hopefully not too onerous for the occasional spoke replacement.

After two years with these wheels, I still haven't had to swap a single spoke out, so perhaps there's no reason to fear the perceived inconvenience of the replacement procedure. Regardless, the slightly less intuitive process may be a turnoff to some, but feels like a similarly annoying job to re-taping a rim. In my case, I swap tyres more than I replace spokes, so it feels like the tradeoff is worthwhile. I also tend not to have too many issues with tubeless tape getting damaged, but I know that for some folks it's a weak point in the system.

Warranty

Fulcrum offers a simple 2-year warranty on all of their products, available only to the original purchaser. In a market where there are plenty of competing companies offering longer span or even lifetime warranties on their wheelsets, this isn't the best option, but hopefully Fulcrum can provide replacement parts as needed at a reasonable cost to the customer. Luckily, I've had no durability issues with the Metal Carbons, but accidents happen and wheels break.

Ride Impressions

I love quiet wheels. Loud hubs appeal to some, but there's nothing quite like a silent bike, so I always choose on the quietest options when given the choice. As far as pawl-driven hubs go, these are the quietest I've used, hands down. A sprag clutch system like those used in Onyx hubs is truly silent, but I have yet to spend much time on those on a personal bike.

Love of silence aside, there's a lot more to these wheels than their relative quiet. The unusual ridge that runs along the centre of the rims may look odd, but achieves a similar effect to the wavy forming seen on WeAreOne's Convergence rims, effectively straightening the line from the nipple seat through the spoke, and keeping tension more consistent for a longer time. The Fulcrums have been surprisingly maintenance-free when it comes to maintaining spoke tension, despite hundreds of miles over the past couple years. The occasional true and tension is obviously required, like any wheelset, but when compared with others in this category, I'd say the Metal Carbons have been uniquely consistent.

One other key detail adds to the silent nature of these wheels - the lack of spoke contact through the lacing pattern. Other wheelsets employ this same method, and it always seems to result in a quieter and more confident feeling wheel, especially on shorter-travel bikes. As a wheel flexes and deflects through corners and impacts, having little to no noise out of the spokes just makes it feel like less is happening to the bike, calming down the experience. That may seem touchy-feely and nitpicky, but when you're dropping 1,600 Euro on a wheelset, you want the little details to be considered.

Speaking of small details, there is one thing I'd prefer to see changed on the stock build for these wheels, despite not having any issues over the review period. Alloy nipples are an annoyance I'd rather do without, as they round out far too easily compared to their brass counterparts. The 30 gram difference between the two isn't enough to be worthwhile for me, especially given the fact that this wheelset clocked in at 25 grams heavier than the claimed weight anyway - it's essentially within their margin of error. Again, I haven't yet had issues, but given the minimal weight difference it feels like an easy detail to rectify.

One more detail I'd add to my wishlist? A 6-bolt version. I understand the convenience and weight savings one can achieve with a Centerlock system, but time and time again I find myself preferring the simplicity and ease of ownership that comes with a 6-bolt hub. No adapters, no special rotors, no bulky tools.

Ultimately, the ride feel of the Metal Carbons is neutral, with enough wiggle and flex to match the character of a shorter-travel bike nicely. I've been riding them on the Tallboy 5 and 6 primarily, which both punch above their travel numbers and allow for some reckless riding. Despite plenty of that, the Fulcrums have held shape and kept the bike tracking as you'd hope through chop and berms alike. The slightly wider 32mm internal width hasn't yielded any weird tyre shapes, even on the 2.4" casings I tend to run on shorter-travel bikes.

Pros

+ Light, comfortable, precise

+ Very quiet hubs and spokes

+ Durable, despite some skepticism

Cons

- Centerlock only

- No 6-bolt option

- Undrilled design will turn some away

Images supplied with this review

Images: MTBSA contributor. Charts retain the currencies and measurements shown in the original.

For South African readers

Overseas prices in this report are not confirmed South African retail prices. Check local availability, warranty support and the complete rand price with your retailer. No MTBSA test score has been assigned.