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Extralite MDX Mountain hub

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  • #92986

    Interbike prep has kept me away from the blog lately, but I felt I needed to make a little time to share this.  A prototype of the upcoming Extralite MDX hub arrived here last week.  While it does have some visual changes, the most dramatic changes are on the inside.  The internals start with a 17mm oversized aluminum axle put into a pair of 6903 (30mm x 17mm x 7mm) bearings.  The freehub body runs on a pair of 6803 (26mm x 17mm x 5mm) bearings.  It’s pretty impressive that with bearings of this size they can still keep the weight down to an impressive 177 grams.

    The most dramatic change in this hub comes in the pawl system, or more correctly in the removal of the pawl system.    The new system is being called a front-engagement system by Extralite.  Similar to what’s done in the DT hubs, but significantly lighter.  The inside face of the freehub is ramped, sorry I didn’t feel like counting the number of them but they are substantial.  One detail I appreciated is that the vertical face of them is actually not vertical but actually goes several degrees beyond 90 making it more of a hook.  The opposing plate is also aluminum is is supported by 3 small springs placed into the hub shell.  It’s really a very simple yet elegant design.

    I’m told that the production version which I believe will be called the Hyperdisc is expected to be a few grams lighter and possibly a little quieter, though this one is not unusually loud for this design type.

    The straight pull spokes and micro tuner pre load adjuster are carried over from the prior the SPD hub.   As well the cost is expected to be within about 10% of the current SPD hub.   Expected release date is sometime near the end of Sept or beginning of Oct.

    Built into a set of Edge 26″ clinchers with some Pillar spokes this rear wheel weighed 614 grams and the matching front was 534 grams making a sub 1150 gram wheelset.

    A ride report will be coming soon.


    Hi Jason, many thanks for this article.
    I`ve used to use Extralite products, and to be honest, waiting for new HyperHubs since beg of summer.
    Do you know, by chance, either the bearings are ceramic, by default or not?
    Have a nice day.
    Peter, Slovakia

    Jon Partington

    Looks really nice… but without being a kill-joy, doesn’t DT have the “star Drive” / “Front Engagement System” covered by Patent?…

    Keep up the interesting posts though!!!

    Cheers, Jon



    There’s a few companies doing similar engagement systems including Soul Kozak, Tune and Extralite. This one is different to DT Swiss’ one difference being that instead of two plates one is integrated into the free-hub body. I’m not going to venture into what this might mean to a patent lawyer but I’m sure Extralite is legally covered, however that might be.

    I run the Facebook Page, Twitter Account and write code the rest of the day.
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