TriRig: Review of FSE Filament-Wound Wheels

TriRig: Review of FSE Filament-Wound Wheels

There are definitely a LOT of wheels on the market. Over the past 5-10 years, there has been a lot of homogenizing of the marketplace. Everyone is making wider rims. Everyone is making making rounder inner edges, to better serve as a leading edge at the back half of the rim (the Firecrest effect). So manufacturers have looked to other areas to differentiate themselves. Zipp gave their wheels whale fins. HED and Mavic created textured brake tracks to improve braking performance. Companies like FLO compete with aggressively-lower pricing. But shapes, weights, and features have largely gotten pretty similar across the market. 

So when I see something truly new, I tend to get excited. Today we're looking at rims by FSE, which are made by an entirely different process from most carbon wheels in the industry. It's made by a filament-winding process. That's right in the name: FSE stands for Filament Spin Evolution. Instead of being laid up in a mold with individual sheets of carbon, FSE rims are wound from a spool of tensioned carbon thread, in a continuous fashion, reducing the number of manual processes in the creation and resulting in a more uniform construction. That doesn't appear to be visible, as the outer layer of carbon on these rims is a 2x2 twill that looks to have been bonded on top of whatever filament-wound structures are underneath. There are a few companies dipping their toe in the waters of filament-winding, some of which don't appear to have a woven outer layer, showing off more evidence of the filament winding process. In any event, FSE is the first set utilizing this type of process that we've gotten our hands on. And they're beautiful. 

But a beautiful appearance is not the real game here. The nature of the filament-winding process is that, due to the better control involved in the creation of the shape, the amount of resin needed to make the wheels is reduced. And, as mentioned, voids (areas where carbon or resin didn't end up where they should have) are virtually eliminated. And the result is a structure that is stronger, stiffer, and yet also lighter than a traditional rim.

We hear claims of "lighter, stronger, stiffer" all the time. But in the case of the FSE rim, it's genuinely true. In fact, when we went to build our next ultralight bike project, we turned to FSE's new 23T rim, which allowed for an absolutely feathery 884g complete wheelset. Compared to Zipp's latest 202 NSW hoops, it's a savings of over ONE POUND. Of course, that's not a necessarily fair comparison, as Zipp is no longer making tubular wheels, and the Zipp set does come with some very nice brake ShowStopper brake tracks. But for pure uphill climbing wheels, FSE is virtually unbeatable. We got that set, for an ultralight build we are working on, and we will show it to you soon. 

But after we got over the novelty of the ultralight climbing set, we noticed that FSE also makes some very nice aero wheels. That's the real upshot here: the wheels we're reviewing today feature the exact same technology as those ultralight wheels, just in a deeper shape, with less expensive hubs. They sent us their FSE300 series, a budget line that starts at $995 for a complete set of carbon clinchers. This is really outstanding pricing, especially for what you get. It's FSE's same filament-wound technology, producing some exceptionally light wheels at an unbeatable price. 

The rims are the same ones featured with the company's more expensive wheelsets, but laced to more budget-friendly hubs with standard black or white logos. They're about $1000 per set, with the shallower 55mm front and deeper 79mm rear. And they're awesome. FSE makes more expensive builds with fancier hubs, more logo options, etc. But the meat of the wheels, the rims, are identical across the board for each given rim depth. There's no "high-mod" premium rims or anything like that. Every rim FSE sells is the best rim it can make at that depth.

Now, the critiques. I do miss the more advanced brake tracks on some other wheels (like Zipp's ShowStoppers, Mavic's Exalith, or HED's Jet Plus), as those do make a very real and very practical difference in the usability of the wheels, especially in wet weather. FSE's brake tracks are just bare carbon. It is laser etched to provide a bit more friction, but doesn't have the same type of texturing or material application you'll find on some of the aforementioned wheels, which in my experience do improve braking. You'll want to invest in a very good carbon brake pad like SwissStop Black Prince, and even then apply extra caution in wet weather. FSE says that their included ceramic brake pads are actually even better in wet weather than Black Prince, but they do recommend Black Prince as an overall pad as well. 

A potential critique with any new wheel company is their overall competency, reputation, and the potential longevity of their products. In talking with FSE, I did get the sense that they are both competent and careful about the quality of their product. This was corroborated by the wheels themselves, which are quite lovely. But they lack the brand reputation of someone like Zipp or Mavic, which are known quantities in the cycling industry. How they will fare in the court of public opinion is something that only time will tell. 

Also a bit of a mystery to me: how exactly are rim shapes made in a filament-winding process? All filament winding information I could find was for cylindrical-type shapes, where the mandrel is capped and gripped at either end. Theoretically, you could use the same type of tooling used to make an electromagnet, where copper filament is wound around a torus. But at first blush, that concept only applies to the outer shape of a rim. It's not readily apparent how that process could be used to form the complex shape of a tire bed, or the spoke reinforcement area. Given that there appears to be an outer layer of carbon fabric on the outer surface of the rim sidewalls, I expect there is some secondary molding process for the tire bed and nipple reinforcement bed. 

I'd really like to see a video of FSE's tooling in action, but FSE has been pretty tight-lipped about their tooling and processes, keeping secret as much of their intellectual property as possible. Their website makes some opaque references to filament winding, but nothing that really shows off how they make their wheels. While that is certainly an understandable position, it can be frustrating for the critically-minded gear head who wants to pick apart, understand, and evaluate the processes and claims of any given manufacturer. FSE is, instead, going to rely on the quality and reputation of their final product. From where I'm sitting, they'll have no problems there. The wheels are gorgeous, ride beautifully, and are ultimately very impressive. I look forward to seeing more from FSE as time goes on.