Fork ends and dropouts

What do you call the slot on a bike where the wheel axle slides in and out?

I follow Sheldon Brown as my authority on this bike nomenclature: Those slots are always fork ends, whether they’re on the front or the rear. If these slots angle down a little so the wheel can drop out, then these fork ends are also dropouts. Because of laziness or carelessness, though, I’ll sometimes call horizontally slotted fork ends “dropouts,” too. And if you call a horizontal track ends “dropouts,” I likely won’t get all pedantic on you and correct you — you’ve communicated to me and I know what you’re talking about, so I won’t feign confusion just to be a jackass.

To review:

This fork end is a diagonal dropout as was common on steel bikes in the 80s…

Fork Ends and Dropouts

Here’s an itty bitty vertical dropout on a modern road bike…

Fork Ends and Dropouts

Here’s a horizontal fork end that’s not a dropout…

Fork Ends and Dropouts

I think the the ends of front forks are always dropout style, though I expect somebody will now find a counterexample of a horizontally slotted front fork end.

10 Comments

  • ark
    February 6, 2009 - 2:13 pm | Permalink

    fox forks now have diagonal front dropouts (but still dropouts). I think this was to counter the fact that the forces a disk brake puts on a fork is trying to pull the axle out of the dropouts. There's a whole ranty web page about that somewhere…

  • ark
    February 6, 2009 - 9:13 pm | Permalink

    fox forks now have diagonal front dropouts (but still dropouts). I think this was to counter the fact that the forces a disk brake puts on a fork is trying to pull the axle out of the dropouts. There's a whole ranty web page about that somewhere…

  • GhostRider
    February 6, 2009 - 3:23 pm | Permalink

    I've seen a vaguely slotted front fork dropout, perhaps on a French porteur bike? — the theory was that the wheel could be adjusted to help carry a front load. Basically, one position for loadless riding, the other for with a load.

  • GhostRider
    February 6, 2009 - 10:23 pm | Permalink

    I've seen a vaguely slotted front fork dropout, perhaps on a French porteur bike? — the theory was that the wheel could be adjusted to help carry a front load. Basically, one position for loadless riding, the other for with a load.

  • Alison Chaiken
    February 7, 2009 - 12:03 am | Permalink

    Anyone else think that carbon dropouts are highly questionable? There's a lot of force on those puppies. Perhaps a carbon-steel bond is more questionable than a carbon dropout, though.

    Some of the choices folks make in the interest of lower frame weight strike me as iffy in general, but that's a different rant.

  • Alison Chaiken
    February 7, 2009 - 7:03 am | Permalink

    Anyone else think that carbon dropouts are highly questionable? There's a lot of force on those puppies. Perhaps a carbon-steel bond is more questionable than a carbon dropout, though.Some of the choices folks make in the interest of lower frame weight strike me as iffy in general, but that's a different rant.

  • Yokota Fritz
    February 7, 2009 - 11:01 am | Permalink

    Alison, isn't there metal under the CF at the dropouts? (I don't know, but it seems like I've heard that. Time to ask Calfee about this!)

  • Yokota Fritz
    February 7, 2009 - 6:01 pm | Permalink

    Alison, isn't there metal under the CF at the dropouts? (I don't know, but it seems like I've heard that. Time to ask Calfee about this!)

  • GhostRider
    February 8, 2009 - 10:29 am | Permalink

    I'm with Alison — there are quite a few frames and forks on the market with compressed carbon dropouts (with NO underlying metal). Seems like a damn bad idea to me, but these bikes are probably geared towards semi-pro/pro racers who get new frames every season. Or dentists who can afford a new frame every year or two.

  • GhostRider
    February 8, 2009 - 5:29 pm | Permalink

    I'm with Alison — there are quite a few frames and forks on the market with compressed carbon dropouts (with NO underlying metal). Seems like a damn bad idea to me, but these bikes are probably geared towards semi-pro/pro racers who get new frames every season. Or dentists who can afford a new frame every year or two.

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