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An IDEA R1 road bike with CALOBRA carbon wheels in action

IDEA / CARBON ROAD WHEELS

CALOBRA

Performance and ride comfort.
Refined down to the last spoke.

Discover the three ranges Compare all models
35 / 45 / 55Rim depths in mm
23 mmInternal width
up to 140 kgWeight limit by range

ONE FOUNDATION, THREE CHARACTERS

Find your
kind of speed

CALOBRA, EVO and ULTRA share IDEA carbon rims in depths of 35, 45 and 55 mm. They differ in hubs, spoke construction, overall weight and weight limit. From proven DT Swiss components to IDEA’s own carbon system.

Each range has its purpose. Explore the construction, individual components and detailed specifications of all nine standard configurations.

01 / WEIGHTfrom 1 090 g

The range’s catalogue figure. See the comparison for weights by specification.

02 / CARBON SPOKESLighter spokes

Greater strength, lower weight. The catalogue lists weight savings of up to 200 g.

03 / TUBELESS SYSTEMmilKit

A tubeless kit for IDEA CALOBRA wheels and a compatible wheel and tyre combination.

04 / OUR OWN SIGNATUREIDENTITY BLACK

Matt black with understated IDEA graphics. A design that complements your bike.

01 / MODEL RANGES

CALOBRA
EVO ULTRA

Shared rims. Different spokes and hubs.
Choose the character that suits your riding.

01Reliability for every mile
A pair of IDEA CALOBRA carbon wheels

IDEA CALOBRA

The standard range combines IDEA carbon rims, DT Swiss AEROCOMP spokes and DT Swiss 350 hubs. It is designed for riders looking for durability, strength and long-term reliability with straightforward maintenance.

Lower weight than conventional wheelsets helps acceleration. CALOBRA focuses on build quality and a balanced combination of price and performance.

Hubs
DT Swiss 350 SP CL
Spokes
DT Swiss AEROCOMP SP
Spoke holes
24 / 24
Weight limit
120 kg
Pair weight
1 340–1 540 g

Range character IDEA rating

85 / 100
95 / 100
90 / 100
Choose CALOBRA
02Carbon spokes. A lighter feel.
A pair of IDEA CALOBRA EVO carbon wheels

IDEA CALOBRA EVO

EVO builds on the same foundation as CALOBRA and adds IDEA EVO CARBON spokes. The spokes are compatible with common hub types and standard nipples, keeping the wheels practical to service.

DT Swiss 350 hubs are paired with the low weight and high strength of carbon spokes. The result suits riders who want proven construction with the benefits of carbon spokes.

Hubs
DT Swiss 350 SP CL
Spokes
IDEA EVO CARBON SP
Spoke holes
24 / 24
Weight limit
130 kg
Pair weight
1 190–1 390 g

Range character IDEA rating

100 / 100
95 / 100
95 / 100
Choose CALOBRA EVO
03The ultimate combination of IDEA components
A pair of IDEA CALOBRA ULTRA carbon wheels

IDEA CALOBRA ULTRA

The top CALOBRA range pairs IDEA’s own F1 ULTRA hubs with IDEA ULTRA CARBON spokes. Rim, hub and spokes form a system focused on maximum performance.

Its character comes from a 54-tooth ratchet, carbon spokes with a 4 mm thread and a choice of stainless steel or ceramic bearings. ULTRA advances IDEA’s own technical signature.

Hubs
IDEA F1 ULTRA SP CL
Spokes
IDEA ULTRA CARBON SP
Spoke holes
21 / 24
Weight limit
140 kg
Pair weight
1 180–1 380 g

Range character IDEA rating

100 / 100
100 / 100
100 / 100
Choose CALOBRA ULTRA

Rim depths of 35, 45 and 55 mm are available in all three ranges. The character ratings are an indicative manufacturer comparison, rather than measurements of physical quantities.

IDEA CALOBRA carbon rim profilesIDEA CALOBRA / EVO / ULTRA

02 / CARBON RIMS

A profile that
brings it all together

The new generation of IDEA CALOBRA rims offers depths of 35, 45 and 55 mm. The geometry focuses on aerodynamics, with a shared internal width of 23 mm.

Hookless construction supports higher-volume tubeless tyres and lower pressures. The aim is lower rolling resistance, greater comfort and efficient power transfer.

23 mmInternal width
28 mmExternal width
3 depths35 / 45 / 55 mm
Choose an individual rim
Matt black IDEA carbon rims with understated IDENTITY BLACK graphics

IDENTITY BLACK

Understated. Distinctively IDEA.

Matt black and subtle graphics unite the rims across the range. The finish complements the bike’s design and lets the construction speak for itself.

The graphics also serve as a trademark and are not intended to be removed. Each rim has an additional marking inside the profile, opposite the valve.

HOOKLESS / COMPATIBILITY

The right tyre
The right pressure

The CALOBRA catalogue specifies hookless-compatible tubeless tyres in size 28-622 and larger. Tyre dimensions follow ETRTO markings – European Tyre and Rim Technical Organisation.

The rims support tubeless setups and conventional inner tubes. Both require a compatible tubeless tyre.

5.5 barMaximum pressure listed in the CALOBRA catalogue

Observe the tyre’s own pressure limit too, and use the lower of the rim and tyre limits. Check compatibility and pressure for your specific setup.

Tyre and pressure guide

RIM GEOMETRY

Three depths
Precise dimensions

The same rims for CALOBRA, EVO and ULTRA.
The construction has undergone internal aerodynamic and load testing.

Scroll the table horizontally.

IDEA CALOBRA rim geometry
ModelDepthInternal / external widthWeightERDType
IDEA R35 CALOBRA35 mm23/28 mm340 g570 mmhookless
IDEA R45 CALOBRA45 mm23/28 mm380 g550 mmhookless
IDEA R55 CALOBRA55 mm23/28 mm440 g530 mmhookless

ERD is the effective rim diameter used for spoke length calculations. A compatible tubeless tyre is required for both tubeless and inner-tube setups.

03 / HUBS

A reliable foundation
Or IDEA’s own system

DT Swiss for CALOBRA and EVO.
IDEA F1 ULTRA for the top range.

DT Swiss 350 hubs for IDEA CALOBRA and CALOBRA EVO wheels

CALOBRA / CALOBRA EVO

DT Swiss 350 / 240 / 180

Standard specifications use DT Swiss 350 hubs. All CALOBRA and CALOBRA EVO models also offer the higher-end DT Swiss 240 or 180. Choose your hubs on the shop product page.

Standard model
DT Swiss 350 SP CL 24/24
Ratchet
36 teeth
Bearings listed in the catalogue
TPI stainless steel
Freehub / option
SRAM, Shimano, Campagnolo
Thru-axles
100 × 12 / 142 × 12 mm
Hub weight
360 g
IDEA’s own F1 ULTRA hubs

CALOBRA ULTRA

IDEA F1 ULTRA

IDEA’s own hubs feature a redesigned construction, bearings and a 54-tooth engagement system. TPI stainless steel bearings are standard; DT Swiss ceramic bearings are available when configuring.

Model
IDEA F1 ULTRA SP CL 21/24
Ratchet
54 teeth
Bearings
TPI stainless steel / DT Swiss Ceramic
Freehub / option
SRAM, Shimano, Campagnolo
Thru-axles
100 × 12 / 142 × 12 mm
Hub weight
340 g
A close-up of the IDEA F1 BODY engagement system with 54 teeth

IDEA F1 BODY

54 teeth
Quick engagement

The IDEA drivetrain uses a 54-tooth mechanism for direct power transfer and a short engagement delay. It is available with TPI stainless steel or DT Swiss ceramic bearings and SRAM, Shimano and Campagnolo freehub options.

04 / SPOKES

From proven steel
to our own carbon

Profile, thread and weight of each spoke type.
Here is what sets the ranges apart.

CALOBRADT Swiss AEROCOMP SP

Steel spokes

DT Swiss AEROCOMP SP

A proven spoke setup focused on strength, reliability and aerodynamics. The standard choice for the CALOBRA range.

Profile
2.1 × 1.2 mm
Thread
2.0 mm
Spoke weight
5.5 g
Spoke set weight
264 g
Conventional DT Swiss spokes
CALOBRA EVOIDEA EVO CARBON SP

Carbon spokes

IDEA EVO CARBON SP

Carbon spokes combine low weight and high strength. According to the IDEA catalogue, their aero profile reduces spoke aerodynamic drag by up to 15%.

The construction retains standard nipples and compatibility with common hubs. The wheels can be trued conventionally and spokes replaced individually.

Profile
3.0 × 1.4 mm
Thread
2.0 mm
Spoke weight
2.5 g
Spoke set weight
123 g
Conventional truing · Individual spoke replacement
CALOBRA ULTRAIDEA ULTRA CARBON SP

Carbon spokes

IDEA ULTRA CARBON SP

IDEA’s top carbon spoke system uses an aerodynamic profile and a thread for 4 mm-diameter nipples. It combines low weight, strength and individual spoke serviceability.

The catalogue specifies spoke tension of 140 kg. ULTRA also allows conventional truing and individual spoke replacement.

Profile
3.6 × 1.0 mm
Thread
4.0 mm
Spoke weight
2.5 g
Spoke set weight
128 g
Conventional truing · Individual spoke replacement
The milKit tubeless system for IDEA CALOBRA wheels

TUBELESS SYSTEM

Ready
for milKit

IDEA CALOBRA wheels can be fitted with a milKit tubeless kit. The right combination of rim, compatible tyre and tubeless system helps you make the most of the wider internal profile.

Choose a tubeless system

IDEA / EXPLORE THE DETAILS

CALOBRA
in motion

Open the video separately

05 / FULL COMPARISON

Nine configurations
Every number

Weight, hubs, spokes and weight limit.
Always compare the specific model and specification.

Showing 9 of 9 configurations

Scroll the table horizontally.

Standard IDEA CALOBRA wheelset specifications
ModelHubsSpokesSpoke holesWeight limitWeightShop priceOptions
IDEA R35 CALOBRADT SWISS 350 SP CLDT SWISS AEROCOMP SP24/24 holes120 kg1340 gfrom 29,900 CZKChoose in the shop →
IDEA R45 CALOBRADT SWISS 350 SP CLDT SWISS AEROCOMP SP24/24 holes120 kg1410 gfrom 29,900 CZKChoose in the shop →
IDEA R55 CALOBRADT SWISS 350 SP CLDT SWISS AEROCOMP SP24/24 holes120 kg1540 gfrom 29,900 CZKChoose in the shop →
IDEA R35 CALOBRA EVODT SWISS 350 SP CLIDEA EVO CARBON SP24/24 holes130 kg1190 gfrom 36,900 CZKChoose in the shop →
IDEA R45 CALOBRA EVODT SWISS 350 SP CLIDEA EVO CARBON SP24/24 holes130 kg1260 gfrom 36,900 CZKChoose in the shop →
IDEA R55 CALOBRA EVODT SWISS 350 SP CLIDEA EVO CARBON SP24/24 holes130 kg1390 gfrom 36,900 CZKChoose in the shop →
IDEA R35 CALOBRA ULTRAIDEA F1 ULTRA SP CLIDEA ULTRA CARBON SP21/24 holes140 kg1180 gfrom 36,900 CZKChoose in the shop →
IDEA R45 CALOBRA ULTRAIDEA F1 ULTRA SP CLIDEA ULTRA CARBON SP21/24 holes140 kg1250 gfrom 36,900 CZKChoose in the shop →
IDEA R55 CALOBRA ULTRAIDEA F1 ULTRA SP CLIDEA ULTRA CARBON SP21/24 holes140 kg1380 gfrom 36,900 CZKChoose in the shop →

CALOBRA and CALOBRA EVO are also available with DT Swiss 240 or 180 hubs. Choose the hub type when configuring; changes to the specification affect the final weight.

The range’s catalogue figure starts at 1,090 g. The lightest specific configuration in this table weighs 1,180 g. Always compare weights for equivalent specifications.

Choose wheels in the shop

06 / TECHNICAL DATA

From construction
to the right tyres

Detailed IDEA technical information.
Including testing and servicing information.

Aerodynamic CAD testing

Aerodynamic CAD testing

Aerodynamic CAD test data informs the construction of individual IDEA wheelset ranges.

Open Test LAB
Recommended tyres and pressures

Recommended tyres and pressures

A compatibility and recommended pressure guide for each wheel model. Always check your specific rim and tyre combination.

Open tyres and pressures
IDEA wheel construction data

IDEA wheel construction data

Technical component descriptions, spoke lengths and servicing data for long-term support of each model.

Open construction data

07 / EXPERIENCE ON THE ROAD

Development and miles
Real riding experience

DEVELOPMENT / TOMÁŠ BÁBEK

IDEA development
with Tomáš Bábek

In his review, Tomáš Bábek describes his fifth season riding IDEA ROUBAIX ULTRA wheels. His perspective as a sprinter highlights the demands placed on IDEA wheel stiffness, weight and durability.

At 88 kg and with power reaching 2,300 watts, he values confidence in the equipment, stability and personal servicing. Discover the wider story of IDEA development.

Read the full review
TEST / MALLORCA

CALOBRA ULTRA
on Mallorca’s roads

IDEA testing continues with customers on demanding descents and long rides. Their experience helps verify wheel limits in real-world use.

In this review, customer Honza shares his impressions after riding the wheels in Mallorca. The full article describes his experience with the CALOBRA ULTRA range.

Read the full test

THE TEAM BEHIND IDEA

Our name in the peloton

Rafkarna and its IDEA brand are the main partners of Rafkarna IDEA Cycling Team. Discover its history, sporting results and shared foundations.

IDEA team & development

YOUR NEXT WHEELS

Choose your rim depth
We’ll refine every detail

CALOBRA, EVO or ULTRA. We’ll personally help you choose hubs, freehubs, tyres and the right configuration.

Discuss your choice Browse the wheel range