We have two new highly technical carbon components coming through at Curve: the Carbon Walmer Race handlebar and the Race 380 fork.
They are quite different products, but they have gone through a similar development process. Both are light, both have been tested for rugged gravel use, and both have taken a lot longer to get right than their finished appearance would suggest.
The Carbon Walmer Race weighs 228 g. The Race 380 fork weighs 427 g, including a full 375 mm steerer. Those are low numbers for components that have passed the tough gravel testing standards we require, particularly once the features of the bar and routing options in the fork are taken into account.
We are cautious about claiming that something is the lightest in its category because those claims depend heavily on exactly what is being compared and how it has been tested. What we can say is that we haven't seen many directly comparable products combining these weights, functions and test requirements.
There is also a broader story behind these two parts. After 14 years of Curve, the way we develop components is very different from when we started.
Product development at Curve
We don't draw a shape, send it to a factory and ask them to work out how to manufacture it.
Some of our production relationships now go back more than ten years. That matters because making a genuinely new component requires a very different relationship from ordering an existing product with a few specification changes.
The manufacturing partners we work best with are the ones prepared to solve problems with us. They have their own engineering and production knowledge, and we rely heavily on it. Equally, we need them to be willing to try things that make production harder.
A lot of our requests initially get a no.
Often it is a result of a battle between test requirements, weight and form. Sometimes the moulding process puts limits on a shape. A mounting option or routing path can compromise another part of the structure. A target weight may disappear once the test requirements are applied, or the form might need to be compromised. A small feature that looks trivial in CAD can be a pain to manufacture consistently.
Then the work starts.
We change our 3D models when needed. The factory changes their processes and assess different materials and layup options. Samples are made and tested. Parts fail. Details move. Material gets added in one area and removed somewhere else. We argue over form, technical features and whether something that is difficult is actually impossible. Occasionally we abandon an idea because the trade-off isn't worth it.
There can be many rounds of this before a product is ready.
It is slower than we would like, but we don't want manufacturing partners whose main interest is producing very high volumes of familiar products with minimal development work. That model works perfectly well for plenty of brands. It doesn't suit what we are trying to do. Our brand is built on the mantra of “no shit products” and years of bikepacking and ultra endurance racing. The bike and the parts and components that make it whole are just part of a bigger adventure plan, and the bike can’t let you down especially when you’re in the middle of the outback where the nearest person could be on an orbiting space station.
The Walmer Race and Race 380 are good examples. Much of the development work isn't obvious when you look at the finished parts. In both cases, getting the weight down was only one part of the job. The harder part was getting the weight down while keeping the function we wanted and still passing the relevant test requirements.
Carbon Walmer Race
Curve has been making wide gravel handlebars for a long time. We still like them for bikepacking, expedition riding and a lot of general gravel use.
Gravel racing has moved in a different direction. Racers are spending more time thinking about aerodynamics and frontal area, and the very wide cockpit that works well on an expedition bike isn't necessarily what someone wants for a fast gravel race. The Carbon Walmer Race came out of that change.
We started with what we had learned from the existing Carbon Walmer, but the objective was different. We wanted a narrower position at the hoods without turning it into a conventional road bar. Gravel still requires useful leverage and control in the drops, particularly at speed on broken surfaces. The shape of the Walmer Bar drops works well for this application but we halved the flare.
The result is a 400 mm hood centre-to-centre width, opening to approximately 480 mm outside-to-outside at the drops with 14 degrees of flare.The reach is 65 mm and drop is 108 mm.
That gives the rider a compact position on the hoods, while the drops are substantially wider when more control is useful. It is a fairly simple idea, but it gives the two main hand positions quite different functions.
The top section has also changed. It has a deeper, more aerodynamic profile than the regular Walmer, without consuming all the usable mounting space in the middle of the bar. That was something we didn't want to lose.
A race bike still needs a computer, and depending on the event it may also carry lights, tracking equipment, clip-on aerobars or other accessories. Very aggressive aero shaping can leave surprisingly little useful bar space once the bike is actually built. The central mounting area on the Walmer Race is deliberately broad and reinforced for that reason.
The Carbon Walmer Race is set up ready for internal routing, but for external routing we’ve included subtle hose recesses at the rear of the bar, that won’t interfere with your hand position even if with internal routing, and with bar tape that finishes before covering the tops.
The drops are set up for SRAM Blips, and we have provided for both internal and external cable routing. A rider upgrading an existing bike doesn't necessarily have the same routing requirements as someone building a completely integrated new bike, so we didn't want the bar to depend on one system. For those not using blips, the recesses can be filled with Curve’s Bar Brows before installing bar tape.
At 228 g, there isn't much excess material to work with. That means the laminate design and reinforcement become more important. Removing weight from a carbon component is easy if the test requirement comes down with it. The difficult job is removing material where it isn't doing useful work while keeping enough structure in the areas that see high loads.
The Walmer Race has passed the gravel testing standard we use for this application, consistent with the test approach used for the existing Carbon Walmer range.
Carbon Walmer Race dimensions and features
- Weight: 228 g
- Hood width: 400 mm, centre-to-centre
- Drop width: approximately 480 mm, outside-to-outside
- Reach: 65 mm
- Drop: 108 mm
- Flare: 14°
- Aero-profile top section
- Reinforced central accessory mounting area
- SRAM Blip-ready drops, with Curve Bar Brown supplied to cover the recesses when not in use
- Internal hose routing ready
- External house routing with recesses
- Gravel-standard testing
The Race 380 was a different, perhaps more challenging, engineering problem.
We developed it alongside the Ultra+, but the fork needed to be useful well beyond one Curve frameset. We wanted a relatively light 380 mm axle-crown fork that could suit endurance road, all-road and modern randonneuring bikes, with enough tyre clearance for current builds and enough routing options that the fork wouldn't determine how the whole bike had to be wired. It also had to be elegant with a tight crown and minimal silhouette and support a variety or routing (both hose and dynamo) and mounting (light and fender) options.
The basic numbers of the Race 380 are:
- 380 mm axle-to-crown
- 47 mm offset
- 1.5-inch tapered steerer
- 45-degree integrated crown race
- 375 mm uncut steerer
- 427 g without axle
- Maximum tyre clearance: 45 mm without fenders and 40 mm with fenders
- Gravel testing standards
The 375 mm steerer is intentionally long. We want the fork to be useful to frame builders working on large frames and custom geometries as well as normal production bikes. We have seen significant demand for even more relaxed endurance road bikes from taller rider in the size 61 - 64 size range. A 375 mm steerer allows the Race 380 forks to be used on bikes in this size range and even a little larger.
Race 380 Fork
Brake routing
The Race 380 supports both internal and semi-internal brake hose routing.
For the internal arrangement, the brake hose passes through a dedicated 3D-printed titanium entry port. We chose to make this as a separate part, perhaps even a design feature, rather than treating the hose opening as a simple hole in the carbon. It also gives us better control of the hose direction at entry.
There are also purpose-made covers and plugs for ports that aren't required on a particular build. This sounds like a small point, but multi-configuration products often look unfinished when some of the available routing isn't used. We wanted the fork to look intentional regardless of which routing combination the builder chooses. We think the Race 380 fork looks sharp in all its configurations.
Dynamo routing
The dynamo routing took considerably more work. With the Race 380 fork, a front dynamo cable can be run internally through the fork, with a path into the steerer for use with a steerer mounted dynamo-powered charger. There are also cable openings at the crown for systems that need a wire to come out and another to re-enter around the light or other hardware.
We added another opening low on the steerer. This creates further options for a builder planning a completely integrated wiring system, including a discreet route for wiring heading back towards a rear dynamo light.
The point isn't that every bike will use every opening. Most won't. The aim was to avoid forcing one particular dynamo layout. Different frames, lights and builders solve the wiring problem in different ways, so the useful approach was to provide sensible paths through the fork and then close the unused ones properly.
For the light itself, there is a ruggedised under-crown mounting point.
Fender mounting is included, and the fork uses a flush-mount thru-axle head.
By the time all of those requirements are combined, the fork becomes quite a packaging exercise. The brake hose and dynamo routing, mounting points, tyre clearance, fender clearance, and tight crown dimensions all compete for room in the same area of the fork near the crown that is also the part of the fork that experiences the highest loads.
That is where a lot of the prototype work went.
Getting a fork to 427 g is one thing. Getting it to 427 g with the full 375 mm steerer, flexible routing and mounting options, keeping a tight and minimal crown, while meeting the gravel test requirement, is a more useful measure of what we were trying to achieve.
Why so many routing options?
Integration is useful until it prevents the person building the bike from making sensible choices.
A fully hidden brake hose may be appropriate on a race bike. For other riders easier servicing may be more important. A randonneuring frame with front and rear dynamo lighting has different routing requirements again. We didn't think the fork should decide that for the builder.
This is one reason the Race 380 has more openings, plugs and small hardware than a simpler carbon fork. The extra parts aren't decoration. They allow the same fork to be finished properly in several different configurations.
For us, that is a better form of integration than designing one very neat cable path that only works if the rest of the bike follows the same assumptions.
Useful beyond Curve bikes
Both products were designed to work as standalone components.
The Walmer Race is an obvious upgrade option for an existing gravel bike if the objective is to reduce cockpit weight, narrow the hood position or move towards a more race-oriented setup without losing the wider drop position.
We think the Race 380 has particular potential for independent frame builders.
Fork choice places a lot of constraints on a frame design. Axle-to-crown length, offset, steerer dimensions, tyre clearance and brake configuration are obvious ones. Once fenders, dynamo lighting and internal routing are added, the list of suitable production carbon forks becomes much shorter.
A builder using the Race 380 has a 380 mm axle-to-crown platform with 47 mm offset, clearance for a 45 mm tyre, fender provision, a very long steerer and several ways of dealing with the brake hose and dynamo wiring. That leaves considerably more freedom for frame design.
We would also like to work with more bicycle brands using Curve components in their own projects. We have spent a lot of time and money developing parts that solve fairly specific problems, and there is no reason those parts need to be restricted to Curve complete bikes.
If another frame builder or bicycle company has a project where the Walmer Race or Race 380 fits the geometry and technical requirements, talk to us. We are always happy to discuss supply. The same goes for the other class-leading products in our range, including the Race 415 VGM and Seek 430 FM forks.
Where we have got to after 14 years
One of the useful things about being around for 14 years is being able to look back at old products and see how much the development process has changed.
We understand carbon better. Our factories understand the style of riding we love and why we are so pedantic and demanding. We are better at specifying what matters early in a project, and much better at finding problems in partnership with our suppliers before production.
At the same time, the products have become harder to make.
We are asking for lower weights, more integration, better tyre clearance, cleaner hardware and more configuration options, without wanting to give away durability to get them.
That inevitably produces more prototypes and more arguments with our production partners, and we're comfortable with that.
A good manufacturing partner shouldn't agree with every drawing we send them. They should tell us when something is a bad idea, or when the manufacturing process at scale doesn't support what we are asking for. Our job is to work out whether we should change the design or keep pushing for another way to make it.
The Carbon Walmer Race and Race 380 have both been through that process repeatedly.
They are probably the two most technically involved components we have put into production so far. More importantly, they are a fair indication of how we now approach product development at Curve.
Carbon Walmer Race
228 g | 400 mm at the hoods | 14° flare | SRAM Blip-ready | internal/external routing
Race 380
427 g | 380 mm axle-to-crown | 47 mm offset | 375 mm steerer | 45 mm tyre clearance | brake and dynamo routing options
For retail, frame-builder or bicycle-brand enquiries, contact sales@curvecycling.com.