DT Swiss 240 2020 + Rear Black ISO 6 Bolt Disc Hub
The DT Swiss 240 is the hub most of the pro peloton rides without knowing it, because the 240 lives inside so many branded wheelsets. Buy the 240 bare and lace it to a rim of your choosing and you get the same hub with none of the markup. This page covers the 2020-and-later DT Swiss 240 2020 + Rear Black ISO 6 Bolt Disc Hub, which is the Ratchet EXP generation of the 240: one ratchet fixed in the hubshell, one sliding, a single spring, and a bigger bearing where the old 240 had a small one.
We build a lot of DT 240 wheels. Road, gravel, cross-country, trail; the 240 is the hub we suggest when a customer wants something light that will still be running smoothly in ten years. The 240 comes from the factory in Switzerland and Poland, and the tolerances show the moment you spin one in your hand.
Like every hub we sell, the 240 is only available here as part of a wheel we build. Pick the rim, spokes and nipples in the configurator and the 240 wheel ships from Georgia laced, tensioned and trued.
Design and construction
Ratchet EXP is the refinement of the Ratchet System it has used for decades. The classic 240 used two floating ratchets and two springs; the EXP 240 threads one ratchet into the hubshell so it cannot move, and lets the other slide on a single spring. That freed up room for a larger freehub bearing, moved it closer to the axle end where the load is, and made the whole 240 assembly stiffer. Both ratchets still engage every tooth at once, which is why a DT freehub spreads a hard pedal stroke over the full ring instead of hanging on a couple of pawls.
The DT 240 ships with 36-tooth ratchets for ten degrees of engagement, and the 54-tooth set drops into the 240 by hand if you want under seven. The 240 freehub body pulls off without tools to swap between Shimano HG, SRAM XD or XDR and Micro Spline. The 240 hubshell is machined to a lighter profile than the 350 and rides on sealed cartridge bearings with DT plug-in end caps, so one 240 converts between axle standards with a cap change.
How it rides
A DT 240 is quick and quiet. Engagement is firm without being harsh, the freehub buzz is muted, and the bearings have that slightly viscous, expensive feel when new that settles into near-zero drag after a few hundred miles. On a road wheel the 240 is a large part of why a good handbuilt set feels so much smoother than a factory pair; on a trail wheel it is the freehub that never skips.
The weight saving of a 240 over a 350 is roughly the difference between a good and a very good rim. If you are chasing grams and want the best of the DT mainstream range, the 240 is the one; if you want the same engagement for less, the 350 is on the next page.
Specifications
| Position | Rear |
|---|---|
| Axle options | Thru Axle 12x148mm Boost Rear, QR 5x141mm Boost Rear |
| Driver bodies | Shimano HG 8,9,10 & Dynasys MTB 11spd, Shimano HG 8,9,10,11 & Road 12spd (+$30), Campagnolo 9,10,11 & 12spd (+$30), SRAM XD 10,11 & MTB 12spd (+$48), SRAM XDR 10,11 & Road & MTB 12spd (+$60), Shimano Micro Spline 12spd (+$60) |
| Drillings | 28h, 32h |
| Spoke head | J-bend |
| Brake | 6-bolt disc |
| Left flange diameter | 57.9 mm |
| Right flange diameter | 50.4 mm |
| Left center-to-flange | 37.1 mm |
| Right center-to-flange | 22.6 mm |
| Spoke hole diameter | 2.6 mm |
| Weight | 238g |
| Material | Aluminum |
| Finishes | black |
Which version this is
Version notes. 6-bolt rotor mount, Thru Axle 12x148mm Boost, QR 5x141mm Boost, 28h, 32h, about 238g, in black. If your frame or fork uses a different standard, the other versions of the 240 on this site cover it.
Six-bolt is the original disc mount and still the most universal: any ISO 6-bolt rotor from any brand bolts straight on, rotors are cheap and easy to find anywhere, and the six-bolt flange is a robust, simple interface that has been on mountain bikes for twenty-five years. Centerlock rotors do not fit it.
Sizes, fit and compatibility
The DT Swiss 240 2020 + Rear Black ISO 6 Bolt Disc Hub is offered in the drillings listed on this page, with the axle and rotor options shown in the configurator: centerlock, 6-bolt or rim brake, in road, standard MTB and Boost spacing. The 240 takes J-bend spokes in any gauge we stock. A rear DT 240 covers HG, XD, XDR and Micro Spline freehubs.
We pair the 240 with everything from DT RR and XM rims to ENVE, Reserve, HED, Nox and We Are One carbon. The configurator recommends a spoke count from your bike type and weight and only shows rims that match the drilling you choose.
Build it into a wheel
This hub is live in our Custom Wheel Program for gravel and road disc, mountain bike and fat bike builds. Start a build with the DT Swiss 240 2020 + Rear Black ISO 6 Bolt Disc Hub and the configurator opens with this exact hub pinned at the top of the DT Swiss list — you choose the rest of the parts and it validates every combination as you go.
DT Swiss's testing and certifications
DT Swiss hubs pass through the same Performance Test Center in Biel as its rims. DT Swiss states that its laboratory tests replicate what products endure in the field over the whole product life cycle, under an internal factory standard that ensures compliance with ISO 4210. Hub-relevant methods are the drum test, in which a wheel loaded to its permissible system weight spins on an obstacle-studded steel drum for a specified mileage, and a brake and drive torque test in which cyclic braking and driving torques are applied to the hub while the wheel is locked or driven at constant speed. DT Swiss publishes no bearing-life, salt-spray or water-ingress figures.
the torque test also verifies "the freewheel functionality and durability". DT Swiss states that Ratchet EXP is 15% stiffer and gives longer bearing life through its increased bearing distance, and that Ratchet DEG uses larger steel ratchets to spread load over a larger contact surface. Ratchet EXP units built since 2019 with a 0 or 9 in the middle of the production code are covered by a free-inspection notice for premature ratchet wear.
DT Swiss's videos
From DT Swiss
Certifications
- ISO 4210 / ASTM F 2043 — DT Swiss states its internal factory standard 'ensures compliance with the current international standards (e.g. ISO 4210)' and sets test parameters by ASTM F 2043 riding conditions (self-declared, no certificate published) (source)
- Warranty — 24 months legal warranty against material and manufacturing defects; ball bearings are wear parts and excluded (source)
- Service interval — Clean and re-grease every 12 months (normal use) or every 3 months (extreme conditions) (source)
Sources on DT Swiss's site:
- Performance test center | DT Swiss
- Ratchet EXP maintenance notice | DT Swiss
- FAQ | DT Swiss
- Warranty & Fair-Share | DT Swiss
- Ratchet EXP | DT Swiss
DT Swiss publishes those results; ProWheelBuilder builds the hub into a wheel and does not test it in a lab.
Building it at ProWheelBuilder
DT manufactures the 240; ProWheelBuilder is an independent wheel builder in Georgia and not the manufacturer. Every DT 240 wheel we build is laced by hand, brought up in stages with a tensiometer, stress-relieved and trued before it ships, with spokes cut from the measured ERD of the rim rather than a catalog number.
The configurator prices the wheel live, strikes through combinations that are not made, and shows the estimated ship date before checkout.
Warranty
DT Swiss's warranty. DT Swiss covers its products against material and manufacturing defects for 24 months from purchase, excluding wear parts such as bearings and tubeless tape. Carbon rims and carbon wheels bought new since 1 January 2020 carry an extended guarantee to the first owner against defects in material and workmanship, and DT Swiss runs a paid crash-replacement scheme on carbon wheels for up to ten years from purchase.
ProWheelBuilder. Built into a wheel by us, this part is covered by our own one-year wheel warranty on top of the maker's. For a year we replace broken spokes whatever caused them, and we cover the labor on the wheel - truing, re-tensioning, a rebuild if it needs one. If a rim or hub fails and its maker covers it, we run that claim for you; if the maker says no, you get an eligible replacement rim or hub at 25% off retail. You pay the shipping each way. Wheels built from parts you send us are excluded.
Full terms are on our Policies & Warranty page.
240 2020 + Rear Black ISO 6 Bolt Disc Hub questions
Will my rotors fit this hub?
This is the 6-bolt version: any ISO 6-bolt rotor bolts straight on with six T25 bolts, which is still the most common and the easiest rotor to replace anywhere. Centerlock rotors do not fit it - for those, take the centerlock version of the same hub, listed separately.
What changed with Ratchet EXP on the 240?
One ratchet is now fixed in the hubshell and one slides on a single spring, which allowed a bigger freehub bearing closer to the load and a stiffer axle. Engagement on the 240 EXP is still all teeth at once.
Can I fit the 54-tooth ratchet to a 240?
Yes. The 240 EXP takes the DT 54-tooth EXP ratchet as a drop-in upgrade, no tools required.
Is the 240 worth it over the 350?
If weight matters and the budget allows, yes; the internals are the same but the 240 shell and axle are lighter. If you would rather spend the difference on a better rim, the 350 is the smart choice.
How is the 240 freehub serviced?
Pull the end cap, slide the freehub off, clean and grease the ratchets, reassemble. Ten minutes on the kitchen table.
Is ProWheelBuilder the manufacturer of the DT Swiss 240 2020 + Rear Black ISO 6 Bolt Disc Hub?
We are not. DT Swiss manufactures the hub; ProWheelBuilder's part is the wheel: measuring, lacing, tensioning and truing it here in Georgia.
Which axle spacing does it fit?
Thru Axle 12x148mm Boost Rear or QR 5x141mm Boost Rear. Measure between the inside faces of your dropouts if you are unsure, or text us.
Not sure? Text or leave a voicemail on 470-253-0929 or email info@prowheelbuilder.com — you will be talking to the people who build the wheels.
