frequently asked questions

ACR is an interface, not a product. It stands for Aerodynamic Cable Routing, the fully internal routing standard introduced by FSA and now used across the industry. Hoses and wires leave the levers, run inside the handlebar, pass through the stem, and drop into the frame through the upper headset bearing. Nothing is visible between the bar and the head tube.

Because it is an interface, a bike only routes that way when the whole chain is built for it: frame, fork, headset and cockpit. Columbus builds for it — the one-piece integrated handlebars (Spirit Road, Futura AL-Road, Cento Gravel) are ACR-compatible, and the two-piece Trittico bars can be run either externally or fully integrated.

If any part of that chain is not ACR — most obviously an older frame with no entry port — you run the cables externally. That is not a compromise in performance, only in appearance.

Every current Columbus cockpit part is designed for internal routing. The difference is whether internal is the only option.

Three things have to be true. Miss one and the cables have to run outside.

1. An entry point. The frame needs a port for the hoses and wires — usually just behind or beneath the upper bearing seat, sometimes in the side of the head tube. If your frame's only ports are on the down tube, it is not fully-internal-ready.
2. Clearance at the upper bearing. The bearing, compression ring and top cap all have to leave a channel for the lines to pass through. This is the part frames get wrong most often, and it is why many systems specify an oversize upper bearing.
3. Room at the steerer. A round steerer fills the bearing bore; something has to give. Either the bore grows, or the steerer's profile changes — which is the route Columbus took with the Trefoil steerer.

The quickest check: pull the top cap and stem, look down into the head tube, and see whether there is a moulded or machined channel. If you are unsure, ask the frame's maker — they will know the answer immediately. We are happy to look at photos.

Most fully internal systems make room for the hoses by enlarging the upper headset bearing to 1-1/2". It works, but it forces a wide head tube and a distinctly modern silhouette — which is the wrong answer for a steel or titanium frame with classic proportions.

Columbus took the other route. The patent-pending Trefoil steerer is a trilobe section: the hose channels are moulded into the steerer itself, so the lines run in the grooves rather than in space taken from the bearing. Full internal routing therefore works with a conventional 1-1/8" upper bearing, and the head tube keeps its proportions.

Two forks have it — Futura Trefoil Road and Futura Allroad Trefoil. Both are tapered 1-1/8" to 1-1/2" with a 350 mm steerer, and both take a dedicated Trefoil expander rather than a standard round one. The clamping area is a standard 1-1/8" diameter, so conventional stems clamp to it; follow the Trittico manual for clamping and expander installation.

Yes. Spirit Road, Futura AL-Road and Cento Gravel each ship with five 5 mm spacers, so you have 25 mm of stack to work with while you find your position. They are shaped to keep the routing channel clear — do not substitute generic round spacers on a fully internal build.

The Trittico carbon stem is supplied at -8° with the black sleeve fitted, and gives -13° with the red sleeve. Lengths run 90, 100, 110, 120 and 130 mm; a 110 weighs 199 g.

Beyond that, the adjustment sleeves let you fine-tune the fit without buying another stem: one shifts the angle by -5°, the other adjusts reach by 0 or +5 mm. They are sold separately.

The ACR interface is specified for both electronic and mechanical drivetrains and for hydraulic and mechanical brakes. In practice, mechanical shift housing dislikes the tight radius at the bar-to-stem transition, so shift feel is more sensitive to housing choice and routing length than on an external build.

The Trittico stem is designed for the Columbus Trittico cockpit. To use for another brand's handlebar, check the diameter of the two products.

Start from axle-to-crown and rake — those decide whether the fork preserves the geometry the frame was drawn around. Tyre clearance and axle standard decide whether the wheel fits.

Carbon steerers use an expander plug, not a star nut — the star nut's teeth would damage the laminate. The plug is fork-specific, and the Trefoil forks in particular need the Trefoil expander because the steerer bore is not round.

Two rake options in one fork, set by which dropout inserts you fit. It lets a builder tune trail — or a rider correct handling — without a second fork.

• Futura Adventure — 45 or 50 mm
• Futura Divide — 47 or 52 mm

The change is reversible, but the inserts must be fitted exactly as the instructions describe. Read them before you start.

Yes — two of them.

• Futura Caliper 1-1/2" — tapered 1-1/8" to 1-1/2" steerer, 45 or 50 mm rake, for modern frames with rim brakes.
• Minimal 1" — a 1" straight steerer, 35 mm crown, 367 mm axle-to-crown, 45 mm rake, up to 25 mm tyres, external routing. Available ready-to-paint or in Columbus paint. This is the fork for a classic frame.

Steerers ship long (300 mm, or 350 mm on the Trefoil forks) and are cut to the frame. You can cut the frame yourself, but cutting with an improper saw or in a way that is against company regulations can result in a voided warranty.

Headsets are chosen by the frame, not the fork — the frame's head tube decides the cup type and bore, and the fork only decides the crown race. Match the standard code below to your frame's specification.

They are SHIS codes — the industry's way of describing a head tube without ambiguity. Always written upper / lower.

• The letters describe where the bearing sits. IS (integrated) — the bearing drops straight into a machined seat in the frame, no cup. ZS (zero stack, or semi-integrated) — a cup is pressed into the head tube so the bearing sits inside it. EC (external cup) — the cup sits outside the head tube, adding stack.
• The first number is the head tube bore in millimetres: 42, 44, 52.
• The number after the dash is the steerer at the top, or the crown race diameter at the bottom: 28.6 for a 1-1/8" steerer, 30 for a 1-1/8" crown, 33 for 1-1/4", 40 for 1-1/2".

So IS42-28.6 / IS52-40 reads: integrated 42 mm upper for a 1-1/8" steerer, integrated 52 mm lower for a 1-1/2" crown. A tapered frame, in other words.

The Compass Integrated 1-1/2" Carbon, built to IS42-28.6 / IS52-40 — a 1-1/8" upper and 1-1/2" lower, which is what every current Columbus tapered fork needs from a frame with integrated bearing seats.

It is listed as compatible with Nemo Tig Road (Trittico), King Zydeco, Vigorelli and Vigorelli Steel. If your frame has zero-stack or external cups rather than integrated seats, choose the Semi-Integrated 1-1/2" (ZS44-28.6 / EC44-40) instead.

Every Compass headset uses 45° angular-contact bearings — the fit, stack and function are identical. The ceramic version, offered on the Integrated 1-1/8" Carbon, swaps stainless balls for ceramic: lower friction and a smoother feel under load. It is a refinement, not a requirement. Both are supplied with a gap cap, carbon on the integrated models and aluminium on the semi-integrated 1-1/2".

Because the bars are flared. The first set is the width at the hoods — where you hold the bar most of the time, and the number you should size from. The second set is the width at the drops, which is wider by the flare angle.

So a Trittico Gravel in “420” is 420 mm at the hoods and 490 mm at the drops. Size from the first number as you would any bar; treat the second as the stability you gain when you go down.

On a one-piece bar the stem is the bar, so length and angle are chosen at purchase. Confirm your current stem length and angle on the bike before ordering — there is no adjustment afterwards.

The Trittico carbon seatpost is made in 27.2 mm and 31.6 mm — measure your frame's seat tube bore, or check the frame's specification; do not shim a 27.2 into a 31.6 frame.

Setback comes in three offsets: 0 mm, -15 mm and -25 mm (adjustable). Choose from where your saddle currently sits: if you are already at the back of the rails, take more setback rather than forcing the clamp. The head then micro-adjusts, so saddle angle is set precisely instead of in notches.

Always the figure in the instructions, applied with a calibrated torque wrench. Carbon is unforgiving in both directions — under-tighten and the part slips, over-tighten and you crush the laminate, and neither failure announces itself in advance.

The per-bolt values for the Trittico cockpit are in the instruction manual, and the manual is the authority; it also gives the tightening sequence, which matters as much as the number on faceplates and seatpost heads. Never guess, and never finish a carbon bolt with a hex key “by feel”.

If you are not set up to do this, have a shop fit the parts. It costs less than a handlebar.

We suggest you use it on seatposts, it's used to avoid slipping and increases the steadiness of the system.

3 kg per side, and only when all three bolts of the anything-cage mount are used. Two bolts is not two-thirds of the rating — it concentrates the load and is outside the specification.

The Futura Divide also carries anything-cage mounts; the Allroad Trefoil has luggage eyelets and hidden fender mounts. Fast Gravel and Futura Trefoil Road have no mounts.

Carbon components suffer from external impact damage. Anytime you clamp something on a carbon components do not apply too much force, refer to the user manuals for the correct nM of force. In general, check the bike for visible cracks due to use or impact, or in the clamping the fork should be inspected.

Check immediately for visible cracks or a decrease of stiffness. If there is a laminated part inside a decrease in stiffness is usually a sign that there is an issue. In general, after a crack you should visit an expert in a bike shop to inspect your bike or component.

100kg is a general line for the weight of the rider + the bike. The design is generally considering a weight of less than 100kg total.

All of it is published. The Tubesets pages cover the materials and where each sits; the catalogues carry the dimensioned tables — diameters, wall thicknesses, butting profiles, shapes — for the current steel and titanium ranges.

Each code identifies the tube — its family, dimensions and butting — so a frame can be traced back to exactly what it was built from. The Tube Code Legend decodes them, and the Tube Shapes reference shows the profiles the codes refer to.

That is what Trittico is for. It is a complete, turn-key hidden-cabling package rather than a collection of parts: handlebar, stem, seatpost, fork and bottle cage designed around one routing path, with the Trefoil steerer making it work on a conventional 1-1/8" upper bearing so your head tube proportions stay yours.

The instruction manual documents the routing path, the assembly order and the interfaces you need to design around. Read it before you cut mitres — the port position is the part that cannot be corrected later.

At present, we only offer tubes for purchase to framebuilders.

Use the contact us portion of the website.

Destinations, carriers, timings and costs are set out in full in the shipping policy, including any customs and duty handling outside the EU. Prices on this store are shown in euros.

Yes. The refund policy sets out the window and the condition parts must come back in. If you are in the EU and exercising your statutory right of withdrawal, use the withdrawal form — it is the fastest route and gives you a record.

One request: keep the packaging until you are sure a part fits. Carbon components are easily marked in transit, and a marked part is harder to accept back.

Yes — the parts that get lost or worn are stocked individually: fork expanders in every size, thru-axles, Futura Adventure dropout inserts, Trittico stem adjustment sleeves, headset bearings and gap caps.

If you need something you cannot find, send us the part and, where possible, the code printed on it, and we will tell you what it is.

The warranty covers defect of manufacturing for two years from the date of purchase.