Shimano 600 downtube SIS set up -advice needed

tenbar
tenbar Posts: 94
edited February 2008 in Workshop
Hello

I've just fitted a new 7 speed cassette to the rear wheel of my old road bike and bought a new chain. I need some advice about fitting a new rear derailleur gear cable. The bike is pretty old and has old skool downtube shifters ( Shimano 600). I've fitted a cable but when riding the chain keeps on slipping onto the next smaller cog (a pain when going up a hill). Is this a cable tension issue and if so what's the nest way to install the cable with particular attention to the position of the downtube shifter (it seems to have some markings on it but i don't know what they mean). Any help would be appreciated.
thanks
tenbar

Comments

  • Anonymous
    Anonymous Posts: 79,665
    If youve got the cable tension right then you might have the outers a bit long. I always set them up as short as I can possibly get away with.
    But just add tension to the cable if its still slipping down. And make sre the bit under the bb is ok. That its not loose or anything.
  • tenbar
    tenbar Posts: 94
    what do you mean by "the outers"
  • piedwagtail91
    piedwagtail91 Posts: 781
    the outer, in this case, is the bit of casing from the stop on the chainstay to the mech.
    if these are old dt shifters have you checked that the bolt through the centre of them is tight?
    if it's not fully tight then that can sometimes cause the problem you're describing especially if it's set to friction rather than index.
  • robbarker
    robbarker Posts: 1,367
    The outers don't have an effect on the cable tension; but do make sure the cable-ends are properly fitted and pressed right into the frame stops. There are several gotchas here, for example using brake cable by mistake means the end caps won't fit into the frame braze-ons. Make sure you get the right size for your frame - they have changed over the years!

    Parker International are good and cheap for gear cables and spares.

    It's bad advice to say get them as short as possible - the last bit of outer into the rear mech is too short on a lot of bikes - it should enter the rear mech roughly horizantally , or extra friction will result. Check out the park tools site - it has a good guide to this.

    The advice about checking that the lever pivot bolt is tightened properly is spot on.

    Remember that new cables can stretch a bit, so an adjustment a few miles after initial installation is nothing to worry about.
  • Bon
    Bon Posts: 2
    Had the same problem with gear slipping on a down tube levered bike(non-indexed). Fixed it by taking apart the lever assembly and thoroughly cleaning each washer lever interface with white spirit so they were scratchy-dry as the friction in the lever resists the spring pull of the rear mech. The lever bolt only needed lightish tightening then to do its job. The slightest bit of grease in there can cause the lever to slip. Hope this helps.

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