The Belgie Ultra has been a favourite in the Curve range for years, particularly among endurance road cyclists and ultra-distance racers. It has been the bike of choice for events like the Trans Am Bike Race and Indian Pacific Wheel Race. The new Ultra+ takes that platform further, with increased tyre clearance, revised frame geometry, a more compliant ride and considerably more integration options.
The Belgie Ultra is now being phased out, with the Ultra+ taking its place. Read on for a rundown on what has changed.
1. Much more tyre clearance
The Belgie Ultra accommodated tyres up to 33 mm. The Ultra+ increases that to 45 mm without fenders or 40 mm with fenders.
That extra volume makes a substantial difference to comfort and the surfaces you can comfortably tackle. Fit a fast 32 mm slick and you have an efficient endurance road bike. Fit a wider 40 - 45 mm tyre and rough roads and light gravel become considerably more manageable. Wider tyres are not just for mixed-terrain use, there are plenty of fast 40 mm slick tyres available that turn the Ultra+ into a beautiful modern randonneur bike.
Importantly, we've retained compatibility with mid-compact 2x road groupsets despite the extra clearance.
2. A more comfortable frame
The ride feel has changed, and much of that comes from the frame itself.
The Ultra+ has a heavily ovalised top tube and much more minimal seat stays than the Belgie Ultra. These changes increase compliance through the upper frame, helping to reduce the harshness of long days on rough roads.
We've retained the stiffness needed through the lower frame for solid power transfer. There is little point making an endurance bike more comfortable if it flaps around like a wet fish under load.
Combined with the significantly wider tyre clearance, we expect the Ultra+ to be noticeably more comfortable over long distances.
3. Revised geometry across the entire size range
We've revisited the geometry of every Ultra+ frame size rather than applying the same changes across the range.
On the smaller sizes, we've paid particular attention to minimising toe overlap without compromising handling. On the largest sizes, the front end has been relaxed for a more natural fit and riding position - this change has been a result of studying the data from hundreds of bike fits we’ve done in recent years.
The result is a more carefully proportioned bike across the size range, with geometry suited to long hours on the road and occasional gravel.
4. A completely new carbon fork
The Belgie Ultra used our Race 370 fork. The Ultra+ gets the new Race 380, one of the most technically involved carbon components we've developed.
It has a 380 mm axle-to-crown length, 47 mm offset and weighs just 430 g with its full 375 mm steerer, without the axle. It has passed our harsh gravel testing requirements.
The fork also brings internal or semi-internal brake routing, a 3D-printed titanium hose-entry port, purpose-made port covers, fender compatibility and several dynamo-light mounting and wiring options.
The extra-long steerer is particularly useful for larger frame sizes and riders requiring more height at the front end for frames with extremely long headtubes.
5. Proper dynamo-light integration
We've put considerably more thought into dynamo lighting on the Ultra+. The Race 380 fork has internal dynamo wiring paths, crown-mounted light options, an under-crown mounting point and additional cable openings for different lighting configurations.
The frame has also been designed for fully internal rear dynamo-light wiring, with exits through either the left or right rear dropout for low-mounted lights. There's another discreet exit under the top tube near the seatpost, allowing a rear light to be fitted higher on the seat stays, seat tube or seatpost.
These details make a difference when building a clean, reliable long-distance bike with neverending lighting.
6. UDH compatibility
The Ultra+ moves to the Universal Derailleur Hanger (UDH) standard, allowing a wide range of drivetrain choices, including SRAM T-type derailleurs. This allows the use of gravel groupsets (like SRAM XPLR) as well as mid-compact 2x road groupsets.
7. There's now an AIR Ultra+ option
Alongside the standard titanium Ultra+, we're introducing the AIR Ultra+. It uses the same frame platform but adds a bonded carbon seat tube and our 3D-printed titanium Power Pyramid at the bottom bracket. This is technology we've already developed and proven through the AIR Kev and AIR Belgie.
The AIR version is aimed at riders wanting a more responsive feel under power, while retaining the long-distance comfort and all-road versatility of the Ultra+.
A modern randonneur, built for the way endurance cycling is changing
We designed the Ultra+ with events like the Transcontinental Race (TCR) in mind.
The TCR is predominantly a road event, but its mandatory control parcours can include unpaved sections. Riders also have to deal with poor road surfaces, unpredictable weather and thousands of kilometres of unsupported riding.
For that sort of event, the ability to fit wider tyres, integrate dynamo lighting and retain an efficient road drivetrain makes a lot of sense.
We also have a soft spot for the beautiful, classic randonneur bikes. The Ultra+ is our modern interpretation of that idea, with contemporary materials, tyre clearance and integration but still with the ability to fit fenders. If we were lining up for Paris-Brest-Paris, it would be our pick.
The Belgie Ultra served us extremely well as an endurance road bike. The Ultra+ carries that heritage forward, with a smoother ride over rough surfaces and considerably more versatility for modern ultra-distance riding.