Specialized Allez Cable Routing

alien8
alien8 Posts: 16
edited February 2009 in Workshop
Hi,

I've just taken delivery of a Specialized Allez 2009. All nice and shiny but the gear cable is routed in an odd way. The left shifter (front mech) goes to the right cable stop on the downtube and the right shifter (rear mech) to the left cable stop. This means that underneath the downtube the cable inners are crossed so that they can go in to the correct sides of the bottom bracket cable guide and on to the the front/rear mechs. This means that the cable inners touch where they cross and also slightly with the underside of the downtube. This can't be right can it? The bike came from Evans - I don't know if they would have done the cabling or whether they would have received it like that.

Cheers, Alien8

Comments

  • andy_wrx
    andy_wrx Posts: 3,396
    Sometimes bikes are cabled-up like that.

    Yes the cables do touch where they cross under the downtube, but on the other hand the curve in the cable between shifter and cablestop is cleaner, so some people prefer it one way and some the other.

    My 2004 Allez wasn't like that, nor my Roubaix, but my wife's Sirrus was/is.
    I must admit I'd never seen a bike like that before she got it, but having had a look around since, it's not that uncommon.
  • alfablue
    alfablue Posts: 8,497
    This approach is sometimes favoured because it leads to a straighter run of the cable outers from the bars. Where the cables cross under the downtube there could be some rubbing or friction between the cables but this won't be a problem.

    From Sheldon Brown:
    "Criss-Cross" Cables

    Most bicycles with handlebar-mounted shifters run the rear cable on the right, the front on the left. This causes some awkwardness in routing the length of housing from the shift lever to the frame stops. Due to the need to allow these housings to be long enough to permit the bars to be turned all the way back and forth, the housings often wind up making a reverse bend--for instance, the rear will go from the shifter, which is on the right, swing forward and cross over past the centerline of the bicycle, then back over to the right side of the top tube, before heading down the down tube. These extra bends increase friction, and the fairly forcible contact between the housing and the side of the top tube can damage the finish.
    A neat solution to this is to run the cables "criss-cross" style: The rear runs from the lever, (on the right) around the top tube, and to the cable stop on the left side of the down tube! The front cable crosses over similarly from the left side of the handlebar to the right side of the down tube.

    The bare cables then cross one another under the middle of the down tube, making an "X". The cables may touch where they cross, but they will do so very lightly, since they are both straight...the tiny bit of friction at this crossing is more than offset by the reduction in friction in the smoother-flowing cable housings.

    This technique does not work with over-the-bottom-bracket cable routing, but is doable with most newer bikes that have under-the-bottom-bracket cable routing and cable stops mounted toward the bottom side of the down tube.
  • alfablue
    alfablue Posts: 8,497
    Jeez! Andy beat me! :roll:
  • alien8
    alien8 Posts: 16
    Ah, okay - good job I didn't b$%%ock Evans about it then. I obviously need to get out (to the bike shop) a bit more.

    Cheers, Alien8
  • on-yer-bike
    on-yer-bike Posts: 2,974
    Alien8 wrote:
    Hi,

    I've just taken delivery of a Specialized Allez 2009. All nice and shiny but the gear cable is routed in an odd way. The left shifter (front mech) goes to the right cable stop on the downtube and the right shifter (rear mech) to the left cable stop. This means that underneath the downtube the cable inners are crossed so that they can go in to the correct sides of the bottom bracket cable guide and on to the the front/rear mechs. This means that the cable inners touch where they cross and also slightly with the underside of the downtube. This can't be right can it? The bike came from Evans - I don't know if they would have done the cabling or whether they would have received it like that.

    Cheers, Alien8
    They should not touch the down tube. They will rub the paint away and rattle. Change them so they don't cross over, the mechanic should have known better.
    Pegoretti
    Colnago
    Cervelo
    Campagnolo

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