Sign up for our newsletter


Zipp 404 Firestrike review

Zipp 404 firestrike review
28 Apr 2015

An all new braking surface promises to iron out the flaws of deep section carbon wheels.

A decade or so ago, the wheels that carried a Grand Tour winner to victory could be had for a few hundred pounds. Then carbon technology seeped from the frame into the wheels, and there was a big bang in performance – and cost. The latest in this short history of premium-priced wonder wheels is Zipp’s 404 Firestrike, which promises to change the game for carbon wheels, and we’re eager to see exactly how much difference a wheel can make.

The argument for spending thousands on carbon wheels has changed over time. The likes of Lightweight once convinced us that it was all about low weight, and produced a wheelset that weighed under a kilo. Then Hed and Zipp suggested the crucial factor was aerodynamics, creating the likes of the original Zipp 404, which could save a rider a couple of minutes over 40km. But niggling problems have persisted with deep section carbon wheels – firstly that they can be tricky to control in strong winds, and secondly that they offer poor braking performance. The latest generation of wheels has addressed these fundamental problems above all else.

Zipp 404 firestrike hub

With the previous Firecrest, Zipp created a blunter, wider rim that initially looked less aerodynamic than conventional V-shapes but has since proved to be a faster shape in real-world conditions, though one should note this idea was borrowed from Hed. The Firestrike has taken that logic further, extending the width of the rim from 26.5mm to 27.8mm at its widest point, as well as increasing the inside diameter of the tyre bed by 1mm to 17.25mm. That should mean a larger tyre volume for comfort and a bigger contact patch for grip. But what does that all feel like on the road?

The Firestrikes feel fast. I took the opportunity to race the wheels at regular circuit races and a road race, and I found myself drifting ahead of the pack on descents where I would usually hold back. The acceleration and ability to hold speed was also better than with a more modest aero wheelset. A more subtle comparison was possible when I was testing the Canyon Aeroad 9.0 Ltd equipped with Firecrest wheels. In terms of speed, I saw no difference between the Firecrest or Firestrike, nor was there a palpable difference in stability – the Firecrests stayed steady in crosswinds. The big difference was in the braking performance.

Carbon rims are notoriously bad at slowing down, for two reasons. With carbon fibre it’s hard to build the two brake track surfaces on either side totally parallel. Aluminium, by contrast, can be CNC-machined with exceptional accuracy. Then there’s the way carbon fibre and water interact, with water tending to form a slippery film on a carbon brake track. Zipp promised to solve both issues with the Firestrike. With the textured surface of the brake track, embedded with silicon carbide particles, it aimed to create a more consistent friction for the brake pads. To combat water droplets, a series of visible grooves across the brake track are designed to channel water away from the surface.

Zipp 404 firestrike rim

The Firestrikes offer impressive power and predictability. There was a similar level of brake pad chewing as with Mavic’s Exalith alloy braking surface, and in the dry it felt as effective as any aluminium braking surface I have ridden. Few carbon wheels offer this level of performance, especially from a clincher wheel. In mildly wet conditions the Zipps performed well too, without the braking lag that usually accompanies carbon rims because water needs to be scrubbed off by the pads.

With carbon there’s always the fear of wear. Mostly, this is a superstitious view about the delicacy of carbon fibre, but anyone who has ridden a set of alloy winter wheels into the ground will know that a brake pad can easily abrade any wheel. I rode the Zipp wheelset in all weathers giving it as hard a time as possible, and some limits to Zipp’s promises became apparent. Over months of riding, the external coating of the brake track did seem to wear away. Even when it did, though, the grooves to direct water away were still visible, and the wheel still braked with consistency, only with a little less power and a little more squeaking.

There were also limits in extreme rain. During a torrential road race I found the wheels increasingly uncertain. This was no drizzle – other riders on aluminium rims suffered too. The difference with the Zipps was that when the water was cleared from the rim during braking, the bite from the brake track was substantial, and hard to predict. The transition between ineffective braking on a wet rim to highly powerful braking when the rim was dry was abrupt, leading to the type of jolt that no one would want when riding in a pack. But over time I could learn to swipe the rim clean before letting off pressure as the brake pad bites, and different compounds and pad shapes could also help.

Despite my qualms, Zipp has done the best job so far of creating a carbon clincher for all conditions. This generation is a limited release, but it’s likely the next model year of Zipp’s deep section range will incorporate the technology. Concerns about carbon braking have been part of the drive towards disc brakes, but the Firestrikes prove there’s a place for rim brakes yet.



Read more about: