DT Swiss 350 2021 + Straight Pull Rear Black Centerlock Disc Hub
The DT Swiss 350 Straight Pull Rear Centerlock Disc Hub is the straight-pull version of the hub DT calls its dependable one: the Ratchet System 36 SL freehub, sealed steel bearings and a Centerlock mount, at 229 grams in the 24-hole 12x142 road-disc version. The 28-hole 12x148 Boost version, 236 grams with a Shimano MTB body, is on the same listing.
This is the straight-pull 350; the J-bend 350 Centerlock rear is a separate listing. We build it to order in Georgia.
Design and construction
Ratchet System 36 SL uses two star ratchets pressed together by springs, so every tooth of both rings drives at once; DT has refined the design for decades and it remains one of the most durable freehubs made. Engagement is 36 teeth as standard, with 18 and 54-tooth options in the configurator.
A straight-pull hub holds each spoke head in a slot in the flange, and the spoke runs in a straight line from there to the rim. There is no elbow, and the elbow of a J-bend spoke is where almost every spoke that breaks gives way. The flange also fixes the line each spoke takes, so the hub decides the lacing pattern rather than the builder.
DT lays the straight-pull flanges out separately for each width: the 24h road rear sits at 34.2 and 17.6mm from center with a 46.2mm drive-side flange; the 28h Boost shell moves to 38.6 and 21.4mm with a 48.7mm drive flange.
How it rides
A 350 rear is solid and quiet, with a clean engagement that does not wander as it wears. It is heavier than a 240 by a few tens of grams and costs a good deal less, which is why it is in so many of the wheels we build.
Straight-pull spokes take the spoke elbow out of the most heavily loaded part of the wheel, the drive side of the rear.
Specifications
| Position | Rear |
|---|---|
| Brake | Centerlock disc |
| Spoke head | Straight pull |
| Freehub system | Ratchet System 36 SL (18 and 54 teeth optional) |
| Versions | 24h with 12x142 thru-axle (road disc), 28h with 12x148 Boost thru-axle |
| Weight (DT Swiss) | 229g (24h 12x142, Shimano road body), 236g (28h Boost, Shimano MTB body) |
| Flange diameter | 38.7 / 46.2mm (24h), 39.0 / 48.7mm (28h Boost) |
| Center to flange | 34.2 / 17.6mm (24h), 38.6 / 21.4mm (28h Boost) |
| Freehub bodies | Shimano HG road or MTB, SRAM XD, SRAM XDR, Shimano Micro Spline, Campagnolo |
This version
What this listing covers: the 350 straight-pull Centerlock rear in 24h for 12x142 frames, with 135mm thru-axle and quick-release conversions, or 28h for 12x148 Boost, with a 5x141 quick-release option. Freehub bodies are chosen in the configurator: Shimano HG road or MTB, SRAM XD or XDR, Shimano Micro Spline or Campagnolo.
The matching front is the 350 2021 + Straight Pull Front Centerlock.
Sizes, fit and compatibility
The 24h version fits road, gravel and older mountain frames with 142mm thru-axles or 135mm dropouts with the conversion caps; the 28h version fits Boost 148mm frames.
It needs straight-pull spokes. Choose gravel, road disc or mountain bike as the bike type in the configurator and it recommends a spoke count and shows only rims in the drilling you choose.
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 350 2021 + Straight Pull Rear Black Centerlock Disc Hub and the configurator pins it for you, then checks each choice you make against it.
Testing, standards and warranty at DT Swiss
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
Everything in this section is published by DT Swiss. ProWheelBuilder is the wheel builder, not the tester, and the hub reaches us as the maker ships it.
Building it at ProWheelBuilder
DT Swiss makes the DT Swiss 350 straight-pull Centerlock rear; ProWheelBuilder is an independent custom wheel builder in Georgia, not the manufacturer. We cut straight-pull spokes from DT's own flange geometry and the measured ERD of your rim, lace by hand, bring the wheel up to tension in stages with a gauge, stress-relieve it and true it last.
The configurator shows only straight-pull spokes for this hub, marks the lacing as set by the hub, strikes through combinations DT does not make and prices the wheel 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.
350 Straight Pull Rear Centerlock questions
What is the difference between the 350 and 240 straight-pull rears?
The 240 uses Ratchet EXP and is lighter; the 350 uses Ratchet System 36 SL and costs less. Both take the same freehub standards and both are straight pull.
Can I change the engagement?
Yes. 18, 36 and 54-tooth ratchets are offered in the configurator, and the ratchets can be swapped later.
Do I need special spokes?
Straight-pull spokes only; the configurator hides J-bend spokes with this hub.
Which lacing pattern does it use?
The straight-pull flange sets it, so the configurator shows the lacing step as Determined by hub.
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.
