105 compatibility 5600 vs 5700

munkster
munkster Posts: 819
edited April 2012 in Workshop
Have decided to swap out my 5600 standard double (not my choice!) for a 5700 compact double on an otherwise 5600 groupset.

Is there any reason why the 5700 cranks shouldn't work with the 5600 front mech? A 5700 groupset review in a bike mag suggested it should work (ie. they tried it) despite there being a very small difference in the gap between rings....

TIA anyone.

Comments

  • maddog 2
    maddog 2 Posts: 8,114
    yeah it'll be fine

    only the brakes on the x700 series are not quite compatible with the older stuff (still work but not as well)
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • munkster
    munkster Posts: 819
    Hmmm, thing is I tried after I posted and found that the crank arm rubs on the front mech when in the outboard position, no matter how much I fettle the limit screws, rotate the clamp and move it up and down the seat tube.

    Could it be that I need another spacer on the drive side of the BB? Presume you'd have to transfer one from the non-drive side?
  • ugo.santalucia
    ugo.santalucia Posts: 28,301
    maddog 2 wrote:
    yeah it'll be fine

    only the brakes on the x700 series are not quite compatible with the older stuff (still work but not as well)

    How can brakes not be compatible?
    left the forum March 2023
  • munkster
    munkster Posts: 819
    How can brakes not be compatible?

    He said not quite compatible. Think the new ones pull a different amount than the old ones? They still "work" apparently (from what I've read) but not optimally.
  • mister p
    mister p Posts: 405
    What spacers are you using? There shouldn't be any spacers on a road Hollowtech II.
  • styxd
    styxd Posts: 3,234
    You shouldnt have any spacers.

    My 5600 front mech caught on my cranks. I took a long hard look at it and thought the cage may be a bit bent, so I undid the screw holding the cage together and bent the outer part in so it didnt touch. Problem solved.
  • munkster
    munkster Posts: 819
    Ah, OK, not "with" the bike at the moment so hadn't actively checked for spacers TBH so was guessing based on my MTB endeavours!!
  • keef66
    keef66 Posts: 13,123
    I can also confirm you shouldn't have any spacers for a Hollowtech road double chainset. A triple has a spacer each side.
  • maddog 2
    maddog 2 Posts: 8,114
    How can brakes not be compatible?

    what munkster said. The cable pull is slightly different. Newer STI pull more cable basically.
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • munkster
    munkster Posts: 819
    edited April 2012
    Does anyone know if, were I to get a 5700 front mech (assuming brute force and ignorance ie. bending doesn't work) whether this would work with 5600 shifters? Shimano seem to say no but surely a front mech of all things isn't that sensitive? (Says he who is having millimetre-level issues with crank arms rubbing on one!!)
  • keef66
    keef66 Posts: 13,123
    Any chance the large chainring is installed back to front? That might cause the mech to be set too far out and rub the crank arm. (or it could just as easily have the opposite effect for all I know)
  • munkster
    munkster Posts: 819
    Not sure how that could happen? I bought it as a chainset with the chainrings attached, and despite me being occasionally very dumb it's physically impossible to put the chainset on back to front surely...
  • fosst
    fosst Posts: 45
    The spacing issue is the space between the inner and outer chainrings, the *700 series being further apart. I may be wrong here but I seem to remember reading that the *700 levers and front mech have slightly different pull ratio and pivot to get the movement required, and we are talking of about 1mm difference.
    I was trying to set up 6700 chainset on 6600 shifters and mech and simply could not get rid of chain rub totally..
    tried 6700 front mech with 6600 shifter, tried all kinds of tweaks and adjustments but only a matched set of shifter/mech/chainset got perfect results.
    Probably not what you wanted to hear, sorry. I imagine 99% of the time a *600 and *700 combination would work fine but if you fall into the 1%, well I bit the bullet and bought the matching set.
  • crankycrank
    crankycrank Posts: 1,830
    You can buy shims/washers specifically for mounting between the chainring and spider to move your chainring further outward. Most LBS's should have them and I believe different thicknesses are available.
  • munkster
    munkster Posts: 819
    It's the crank arm that rubs on the front mech cage though not the chainring...
  • crankycrank
    crankycrank Posts: 1,830
    munkster wrote:
    It's the crank arm that rubs on the front mech cage though not the chainring...
    Oh. :oops: I guess you mentioned that already.
  • fosst
    fosst Posts: 45
    Guilty of not reading thoroughly as well.
    Doesn't sound right to me that the limit screw has no effect. Regardless of what lever/mech/chainset you must be able to set the limit of travel.
    Don't know what is happening there. I would remove the chain and release the cable to the mech, move the mech by hand and work on the limit adjustment until it can't reach the crank arm, hopefully then you will have seen and eliminated the problem.
  • munkster
    munkster Posts: 819
    I'm going to have another play tomorrow in the light (and without a long day at work!) and probably do as you say and remove chain etc. Was hoping not to have to break the chain to be honest but looks like that's about the only way I can do this vaguely scientifically.

    Thanks all for suggestions!
  • May be stating the obvious here so apologies in advance. Have you checked it's not just twisted out a tiny bit? I had this with my front mech and it had rotated very slightly causing chain guide to rub..
    Some people are like slinkies - not much use for anything, but they bring a smile to your face when you push them down the stairs.

    http://knownothingbozoandhisbike.blogspot.com/
  • munkster
    munkster Posts: 819
    May be stating the obvious here

    No, obvious is good. But as per my OP (which admittedly is a long time ago) I have tried rotating clamp etc etc. Am about to give it another look in daylight while it looks like it may not rain for another 30 mins or so ;-)
  • munkster
    munkster Posts: 819
    In case anyone's interested I've just had a patient few minutes with the bike, think we understand each other now...

    Took a good hard look at the front mech cage and think the outer plate was a bit bent outwards (on the curved part towards the rear) so applied a bit of pressure there and fiddled around with limit screws again.

    Think it's working now, on the stand at least, with the merest of clearance to the crank arms.

    Been reading up and it seems to be suggested (but not universally agreed upon) that you can/should use a triple (5603) front mech with the compact. Might that help the situation?? Either way think I'm going to have to shorten the chain a touch by the looks of it.
  • munkster
    munkster Posts: 819
    OK, I give up. Works fine on the workstand. But will not shift onto big ring when riding for love nor money...