mavic 851 ssc rear mech problems

SJLcp
SJLcp Posts: 239
edited February 2008 in Workshop
Hi There again

A retro question - I have a very nice mavic 851 rear mech that I am fitting to a vitus 979 frame - the gear combo is 53/39 chainset and regina 6-speed 14-26 - problem is that the mech doesn't look to have anything like the needed capacity - I think I am missing something?

Does anyone know what its capacity and max sprocket should be please? There are some details on velobase but they look suspect (good site though)

http://www.velobase.com/ViewSingleCompo ... 8&AbsPos=7


Many thanks

Simon

Comments

  • notsoracy rich
    notsoracy rich Posts: 229
    The Mavic catologue states the 800 series-which includes 851-allows freewheels with 12-30 teeth, but I presume that allows for the fact they produced a long cage-851-version.
    There is an adjustment-the lower bolt which attaches the chain guide actually goes in a slot so you can slide the bit with the jockey wheels on up or down to clear the sprockets.

    I used to use on of these with a 52/42 and 13/21 block, and have to admit it was never that brilliant wherever you moved the jockey wheels, but improved a lot using a 13-18 straight block.
  • SJLcp
    SJLcp Posts: 239
    Rich

    Thanks for that - I will investigate your tip about increasing the length of the cage by moving it down the slot - I certainly hadn't noticed that trick and can see that it may help things a little. Starting to think that I may need to get one of the later mid length cage mechs - although the later ones just aren't so purty.

    Cheers

    Simon
  • notsoracy rich
    notsoracy rich Posts: 229
    I forgot to say-be gentle with that screw-its very easy to break the top hat shaped threaded nut as its made of aluminium,as are almost all the other bits that aren't stainless steel.

    Rich.
  • SJLcp
    SJLcp Posts: 239
    Thanks Rich

    I tried your suggestion which worked a treat - cage now easily accepts 26 sprocket - only problem is I had to dismantle the cage bolts to slide the cage in its slot and its lost its correct tension - cue lots of fiddling and swearing to get the coil spring tensioned and seated correctly in the barrel - thats tonights exercise.

    Take your point about the materials - its a beautifully made mech but does look delicate.

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