DT Swiss 240 2020 + Straight Pull Rear Black ISO 6 Bolt Disc Hub
The DT Swiss 240 EXP Straight Pull Rear ISO 6 Bolt Disc Hub is the 240 straight-pull rear for riders who run six-bolt rotors: a 28-hole Boost 12x148 shell, Ratchet EXP 36 and a six-bolt rotor mount, at 218 grams with a Shimano MTB body by DT's figure.
It is the mountain bike member of the straight-pull 240 family; the Centerlock version and the J-bend 240 6-bolt rear are separate listings. We lace it to order in Georgia.
Design and construction
The shell uses DT's straight-pull Boost layout: flanges 35.8mm and 21.5mm from center, 35.9mm on the non-drive side and 42.8mm on the drive side. Spreading the flanges that far is what makes a Boost rear wheel stiffer and closer to even tension than a 142 wheel.
What straight-pull changes is the spoke head. Instead of hooking through a hole and bending 90 degrees, each spoke drops into a slot and leaves the flange already pointing at the rim, so there is no elbow to fatigue. The slot also sets the angle every spoke takes, which is why a straight-pull hub dictates its own lacing pattern.
Inside, Ratchet EXP fixes one ratchet ring in the shell and floats the other on one spring, which let DT widen the bearing spacing for a stiffer axle. The six-bolt mount takes standard ISO rotors with no adapter.
How it rides
On the trail the 240 EXP picks up with no slop and stays quiet, and the straight-pull build keeps spoke tension where it was set after rock gardens and drops.
With a 54-tooth ratchet fitted, engagement shortens to 6.7 degrees, which riders on technical climbs notice more than anything else about the hub.
Specifications
| Position | Rear |
|---|---|
| Brake | 6-bolt (ISO) disc |
| Spoke head | Straight pull |
| Freehub system | Ratchet EXP, 36 teeth (54 optional) |
| Drilling | 28h |
| Axle | 12x148 Boost thru-axle (5x141 quick release optional) |
| Weight (DT Swiss) | 218g with Shimano MTB body |
| Flange diameter | 35.9 / 42.8mm |
| Center to flange | 35.8 / 21.5mm |
| Freehub bodies | Shimano HG MTB or road, SRAM XD, SRAM XDR, Shimano Micro Spline, Campagnolo |
This version
What this listing covers: the 240 EXP straight-pull 6-bolt rear in 28h, 12x148 Boost, with a 5x141 quick-release conversion. Freehub bodies are chosen in the configurator: Shimano MTB or road HG, SRAM XD or XDR, Micro Spline or Campagnolo, the last closed until an EXP Campagnolo body is in stock.
If your rotors are Centerlock, the 240 2020 + Straight Pull Rear Centerlock listing is the one to choose.
Sizes, fit and compatibility
It fits Boost 148mm mountain bike frames with a 12mm thru-axle, and 141mm quick-release frames with the QR conversion. It needs straight-pull spokes; for trail riding we usually build with Sapim Race straight-pull spokes and brass nipples.
Choose mountain bike or gravel as the bike type in the configurator; it recommends a spoke count and shows only 28-hole rims for this hub.
Build a wheel around it
Offered for gravel and road disc, mountain bike and fat bike builds in our Custom Wheel Program. Start with the DT Swiss 240 2020 + Straight Pull Rear Black ISO 6 Bolt Disc Hub and the configurator pins it for you, then checks each choice you make against it.
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
We do not make the DT Swiss 240 EXP straight-pull 6-bolt Boost rear, DT Swiss does. ProWheelBuilder is an independent custom wheel shop in Georgia: we measure the rim, cut straight-pull spokes to length from DT's geometry, lace by hand, tension in stages, stress-relieve and finish the wheel true, round and correctly dished.
In the configurator the spoke choice narrows to straight-pull brands, the lacing step reads Determined by hub, and the price is live.
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. If we lace this into a wheel for you, that wheel also carries ProWheelBuilder's own one-year warranty, which covers broken spokes regardless of cause and all wheel-related labor, including truing and rebuilding, for a year from purchase. Where a rim or hub is covered by its maker, we make the manufacturer's claim for you and coordinate it; where it is not, we offer an eligible replacement rim or hub at 25% off current retail. Shipping to and from us is the customer's. This cover does not extend to wheels built from components you supply yourself.
Full terms are on our Policies & Warranty page.
240 Straight Pull Rear 6-Bolt questions
Do I need special spokes?
Straight-pull spokes only; the configurator filters the spoke list to straight-pull brands once this hub is picked.
Is 28 holes enough for trail riding?
For most riders on a modern Boost wheel, yes; DT only makes this straight-pull shell in 28h. Heavier riders who want 32 should look at the J-bend 240 6-bolt rear.
Which lacing pattern does it use?
The flange sets it. The configurator shows the lacing step as Determined by hub, and we lace to DT's specification for this shell.
Can I run Centerlock rotors on it?
No, this is the six-bolt version. Choose the 240 straight-pull Centerlock rear for Centerlock rotors.
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.
