Shimano brake caliper compatibility

curlyrobert
curlyrobert Posts: 150
edited October 2009 in Workshop
Anyone know if last years 105 STI's are compatible with the new Ultegra 6700 calipers?


upgrading the calipers on a Trek Madone 4.5 - it comes with un-branded ones which are the only weak point on a 105/ultegra build.

The shifters are Shimano 105 5600 - looking at a pair of new Ultegra 6700 calipers.

They look great and have all the trickle down technology etc - however I seem to remember reading somewhere that the new 6700 STI's/calipers work slightly differently? does this mean that the calipers are not backward compatible?
the day I stop dreaming of upgrades is the day die!

http://farm4.static.flickr.com/3370/3261181810_727612440a_o.jpg My Stable

Comments

  • chriskempton
    chriskempton Posts: 1,245
    6700 STIs/brakes/mechs have none of the backwards compatability issues of the 7900 DA ones, so yes you can any Shimano or equivalent calipers (except DA 7900) with your 105 STIs.
  • ride_whenever
    ride_whenever Posts: 13,279
    you sure chris? Just read the article on hive brakes and it indicates that the 7900 and the 6700 have the same ratio...
    Neeermad
    Carbon 456
    456 lefty
    Pompino
    White Inbred
  • curlyrobert
    curlyrobert Posts: 150
    I read that review on the Hive brakes too and would indicate that they operate a different system.
    the day I stop dreaming of upgrades is the day die!

    http://farm4.static.flickr.com/3370/3261181810_727612440a_o.jpg My Stable
  • appletrees
    appletrees Posts: 327
    That was my understanding too...
  • curlyrobert
    curlyrobert Posts: 150
    I crumbled and disobeyed the forum code.

    Just got off the phone with Madison.

    Ultegra 6700 & DA7900 are not backward compatible - both STI's pull different amounts of cable due to the new cable routing. F&R mech/brakes and shifters would all need to be replaced...

    Nice! (expensive...)
    the day I stop dreaming of upgrades is the day die!

    http://farm4.static.flickr.com/3370/3261181810_727612440a_o.jpg My Stable
  • chriskempton
    chriskempton Posts: 1,245
    curlyrobert wrote:
    I crumbled and disobeyed the forum code.

    Just got off the phone with Madison.

    Ultegra 6700 & DA7900 are not backward compatible - both STI's pull different amounts of cable due to the new cable routing. F&R mech/brakes and shifters would all need to be replaced...

    Nice! (expensive...)

    The OP wants to run 6700 calipers with 105 STIs though, so this is irrelevant. The incompatability between 6700 with 7900 is because the 7900 stuff is 'non-standard'. 6700 is 'standard'.

    As I said, I believe he can buy 6700 calipers and use them with his current 105 STIs.
  • ride_whenever
    ride_whenever Posts: 13,279
    the 6700 pull a different amount of cable, as curly robert said from his phone call with madison.

    therefore presumably the brakes receive a different amount of cable pull.
    Neeermad
    Carbon 456
    456 lefty
    Pompino
    White Inbred
  • chriskempton
    chriskempton Posts: 1,245
    Oh I think I've misunderstood your post CR.... :oops:

    Interesting, I'm sure I read that 6700 were completely standard, will see if I can remember and dig it out (for my own sanity if nothing else).
  • Smokin Joe
    Smokin Joe Posts: 2,706
    I don't see how a caliper can in anyway be incompatable with a brake lever. The cable is a direct pull from the lever, it doesn't go round a pulley which may be varied in size to alter the amount of travel.

    Where's the problem, apart form in the heads of Shimano's marketing department?
  • maddog 2
    maddog 2 Posts: 8,114
    I know this is an old thread but for any future reference....
    I don't see how a caliper can in anyway be incompatable with a brake lever

    the new 6700 levers pull more (brake) cable than the older Ultegra STI, hence if you use them with non-6700 calipers you'll get less power and a firm lever.

    Conversely, if you use non-6700 STI with new 6700 calipers then you'll get plenty of power but a spongey lever.

    It's all about leverage - you can either have short cable pull with plenty of force, or lots of cable pull with less force. The 6700 STI now pulls more cable, so needs the new calipers to match them.

    [you can replace "6700" with "7900" in the above passage, as they are the same design]

    It's like cantilevers and V-brakes. V brake levers pull much more cable than cantilever levers.

    I'll go back in the garage now....
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer

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