dura ace woes..

blablablacksheep
blablablacksheep Posts: 1,377
edited August 2013 in Workshop
Having issues with my canyon dura ace,

Issues are following, would like feed back from those who know about dura ace;-) (I know it's good and Exspensive that it Lol)

1: front derailaur trimming, seems non existent atm.

2: brakes....modulation is....awful,front brake perfect back brake is worse than MTB!(lbs said dura ace is worse than ultegra with modulation:-\ )

3: maintenance, do I have to index gears every month!? They seem to loose their sharpness very quickly even though atm I'm not cycling that much.

Help thanks
London2Brighton Challange 100k!
http://www.justgiving.com/broxbourne-runners

Comments

  • adamfo
    adamfo Posts: 763
    7900 or 9000 dura ace ?
  • dennisn
    dennisn Posts: 10,601
    adamfo wrote:
    7900 or 9000 dura ace ?

    AND. Are you the mechanic?
  • Bozman
    Bozman Posts: 2,518
    7900 doesn't have trim because there's no need.
  • Grill
    Grill Posts: 5,610
    dennisn wrote:
    adamfo wrote:
    7900 or 9000 dura ace ?

    AND. Are you the mechanic?

    This. DA is smooth as can be when properly set up. Oh and your LBS doesn't know what they're talking about if they actually said Ultegra modulates better than DA (which are known for have the best brakes on the market in terms of modulation and power).
    English Cycles V3 | Cervelo P5 | Cervelo T4 | Trek Domane Koppenberg
  • A common schoolboy error when not using the bike is to leave it on the big chainring and/or the largest rear sprocket. In both cases, the cables are at their most taut and over time will stretch, which won't help shifting performance. I always leave mine on the small chainring and the middle sprocket.
  • Dmak
    Dmak Posts: 445
    A common schoolboy error when not using the bike is to leave it on the big chainring and/or the largest rear sprocket. In both cases, the cables are at their most taut and over time will stretch, which won't help shifting performance. I always leave mine on the small chainring and the middle sprocket.

    Hadn't thought of that. Ta.
  • dennisn
    dennisn Posts: 10,601
    My DA 7900 setup appears to have two positions(trim) when in the small ring. The first time you press the lever the front 'D' moves slightly outboard and enables you to use the outer(smaller rear) cogs. Press the lever again and it moves the chain to the large chain ring. However, only one push of the lever will send it BACK to the "starting" point. So two clicks to get to the large ring and only one to get all the way back. At least that's how mine seems to work. Then again I never claimed to be an ace mechanic.
    On the documents, that came with this 'D', it states that trimming has been done away with???? So, anyone care to guess why mine has two clicks going "up"?
  • majormantra
    majormantra Posts: 2,094
    A common schoolboy error when not using the bike is to leave it on the big chainring and/or the largest rear sprocket. In both cases, the cables are at their most taut and over time will stretch, which won't help shifting performance. I always leave mine on the small chainring and the middle sprocket.

    Myth.
  • Grill
    Grill Posts: 5,610
    dennisn wrote:
    My DA 7900 setup appears to have two positions(trim) when in the small ring. The first time you press the lever the front 'D' moves slightly outboard and enables you to use the outer(smaller rear) cogs. Press the lever again and it moves the chain to the large chain ring. However, only one push of the lever will send it BACK to the "starting" point. So two clicks to get to the large ring and only one to get all the way back. At least that's how mine seems to work. Then again I never claimed to be an ace mechanic.
    On the documents, that came with this 'D', it states that trimming has been done away with???? So, anyone care to guess why mine has two clicks going "up"?

    DA 7900 still has trimming on the small ring. There is no big ring trim as the mech cage is larger thus there will be no rub when properly set up.
    English Cycles V3 | Cervelo P5 | Cervelo T4 | Trek Domane Koppenberg
  • dennisn
    dennisn Posts: 10,601
    Grill wrote:
    dennisn wrote:
    My DA 7900 setup appears to have two positions(trim) when in the small ring. The first time you press the lever the front 'D' moves slightly outboard and enables you to use the outer(smaller rear) cogs. Press the lever again and it moves the chain to the large chain ring. However, only one push of the lever will send it BACK to the "starting" point. So two clicks to get to the large ring and only one to get all the way back. At least that's how mine seems to work. Then again I never claimed to be an ace mechanic.
    On the documents, that came with this 'D', it states that trimming has been done away with???? So, anyone care to guess why mine has two clicks going "up"?

    DA 7900 still has trimming on the small ring. There is no big ring trim as the mech cage is larger thus there will be no rub when properly set up.

    You're very correct in your thinking although I would definitely emphasize the word "PROPERLY". And properly, at least for me, wasn't all that easy. :wink:
  • farrina
    farrina Posts: 360
    Grill wrote:
    DA 7900 still has trimming on the small ring. There is no big ring trim as the mech cage is larger thus there will be no rub when properly set up.
    +1
    My DA 7900 definitely has a trim position for use on the inner ring.. there will be no rub unless you are really trying it on with large chain ring and large sprocket on back in which case it may complain (chain line will be awful though)

    Regards

    Alan
    Regards
    Alan
  • Mccaria
    Mccaria Posts: 869
    And DA 9000 goes back to trim on both big and small rings.
  • NewTTer
    NewTTer Posts: 463
    A common schoolboy error when not using the bike is to leave it on the big chainring and/or the largest rear sprocket. In both cases, the cables are at their most taut and over time will stretch, which won't help shifting performance. I always leave mine on the small chainring and the middle sprocket.

    Myth.
    Agreed this is myth, have you any idea how much pressure would be required to stretch that steel cable, a darn sight more than can be generated by the return spring in the rear derailleur.

    The stretching that people refer to on new installations isn't stretching at all, it is just the cable outers settling into position thus creating the illusion that the cable has "stretched"
  • racingcondor
    racingcondor Posts: 1,434
    NewTTer wrote:
    A common schoolboy error when not using the bike is to leave it on the big chainring and/or the largest rear sprocket. In both cases, the cables are at their most taut and over time will stretch, which won't help shifting performance. I always leave mine on the small chainring and the middle sprocket.

    Myth.
    Agreed this is myth, have you any idea how much pressure would be required to stretch that steel cable, a darn sight more than can be generated by the return spring in the rear derailleur.

    The stretching that people refer to on new installations isn't stretching at all, it is just the cable outers settling into position thus creating the illusion that the cable has "stretched"

    Yeah, I was going to say. Given that the spring in the rear derailleur is soft enough to move with 1 finger how weak is that (hypothetical) cable!

    Bedding in is very much real (outers push into the levers / frame cable stops and housing moving under your bar tape).

    OP - If the bike is new then I imagine it's bedding in you're having problems with but I'm not impressed that your LBS is apparently feeding you BS... :roll:
  • NewTTer wrote:
    A common schoolboy error when not using the bike is to leave it on the big chainring and/or the largest rear sprocket. In both cases, the cables are at their most taut and over time will stretch, which won't help shifting performance. I always leave mine on the small chainring and the middle sprocket.

    Myth.
    Agreed this is myth, have you any idea how much pressure would be required to stretch that steel cable, a darn sight more than can be generated by the return spring in the rear derailleur.

    The stretching that people refer to on new installations isn't stretching at all, it is just the cable outers settling into position thus creating the illusion that the cable has "stretched"

    Yeah, I was going to say. Given that the spring in the rear derailleur is soft enough to move with 1 finger how weak is that (hypothetical) cable!

    Bedding in is very much real (outers push into the levers / frame cable stops and housing moving under your bar tape).

    OP - If the bike is new then I imagine it's bedding in you're having problems with but I'm not impressed that your LBS is apparently feeding you BS... :roll:

    Crickey, I'm not saying it'll happen over night. I'm talking months to a year of leaving it on the big ring when not in use. Whether it's a myth or not, surely it can't hurt can it?

    Tell you what, you just carry on and leave it on the big ring when not in use, because let's face it, it looks better and faster on the big ring.

    :roll:
  • racingcondor
    racingcondor Posts: 1,434
    Sorry TheSmithers, not having a go (and hey, this thread's actually strayed polite which is pretty good for BikeRadar recently).

    If it takes > a year I wouldn't know anyway. I change my cables at the start of each season after having a couple break a few years back.
  • mamba80
    mamba80 Posts: 5,032
    Not sure on the iner cable etc but changing down means less tension on springs in the mechs, maybe more of an issue using them dodgy simplex gears i used to have?

    Also, you are - probably - in the right gear to set off in next time you ride :)
  • ugo.santalucia
    ugo.santalucia Posts: 28,301
    A common schoolboy error when not using the bike is to leave it on the big chainring and/or the largest rear sprocket. In both cases, the cables are at their most taut and over time will stretch, which won't help shifting performance. I always leave mine on the small chainring and the middle sprocket.

    Myth.

    Agree... a stainless steel cable is designed to take probably 100 times the kind of load a derailleur spring can provide
    left the forum March 2023
  • Shimano gear pro tip: gears when set up are normally fairly stable (once the fittings are bedded in) BUT if you find you are adjusting frequently it is time to change the gear cable. Shimano changers are prone to fraying the cable in the changer - happens throughout the range from Sora through to Dura-Ace. If the cable snaps in the changer, you end up with about a 10mm cable with the head somewhere deep in the changer, with the strands nicely splayed out against the direction you need to pull it, which takes persistence and luck to remove.

    What happens is that a strand breaks, then the cable weakens, the next one goes, all hidden within the changer.

    Changing a cable is not too difficult (just tedious trying to get it round to the outer when you have the hidden gear cable versions) and it will save you the grief of the risk of a changer damaged by impossible to extract cable.

    How long to wait to change a cable? I've had a 7900 DA rider wear one out in 6 month, second chain so say 3000 miles, my Tiagra cable went after 9 months - 3000 miles again, got a Ultegra on the stand now with two strands broken in the cable which probably had new cables with the last chain change, chain extremely overworn so I am guessing another 3000 miles. If you don't change gear much then they won't wear much but I am an enthusiastic gear changer.

    So when you have your bike serviced, insist that they change the inner cable for the rear changer if you've done more than a couple of thousand miles since it was last changed. The cable costs them pennies (you more!) but will save you grief.

    BTW, a problem with internally routed cables is that when fitting new cables, giving them a good, string tug is normally the way a mechanic makes sure they are bedded in properly. With internally routed cables there is nothing to get hold of so it is really hard to get enough pull on the cable to bed in the fittings. Over-shifting (e.g. with an overly tight low adjustment screw on the rear derailleur or an overtight cable) is one solution to try and get tension in the cable to force the cable ends home.
  • desweller
    desweller Posts: 5,175
    NewTTer wrote:
    A common schoolboy error when not using the bike is to leave it on the big chainring and/or the largest rear sprocket. In both cases, the cables are at their most taut and over time will stretch, which won't help shifting performance. I always leave mine on the small chainring and the middle sprocket.

    Myth.
    Agreed this is myth, have you any idea how much pressure would be required to stretch that steel cable, a darn sight more than can be generated by the return spring in the rear derailleur.

    The stretching that people refer to on new installations isn't stretching at all, it is just the cable outers settling into position thus creating the illusion that the cable has "stretched"

    Yeah, I was going to say. Given that the spring in the rear derailleur is soft enough to move with 1 finger how weak is that (hypothetical) cable!

    Bedding in is very much real (outers push into the levers / frame cable stops and housing moving under your bar tape).

    OP - If the bike is new then I imagine it's bedding in you're having problems with but I'm not impressed that your LBS is apparently feeding you BS... :roll:

    Crickey, I'm not saying it'll happen over night. I'm talking months to a year of leaving it on the big ring when not in use. Whether it's a myth or not, surely it can't hurt can it?

    Tell you what, you just carry on and leave it on the big ring when not in use, because let's face it, it looks better and faster on the big ring.

    :roll:
    If you don't know how it works you shouldn't post. Bad advice is worse than no advice.
    - - - - - - - - - -
    On Strava.{/url}
  • kettrinboy
    kettrinboy Posts: 613
    Shimano gear pro tip: gears when set up are normally fairly stable (once the fittings are bedded in) BUT if you find you are adjusting frequently it is time to change the gear cable. Shimano changers are prone to fraying the cable in the changer - happens throughout the range from Sora through to Dura-Ace. If the cable snaps in the changer, you end up with about a 10mm cable with the head somewhere deep in the changer, with the strands nicely splayed out against the direction you need to pull it, which takes persistence and luck to remove.

    What happens is that a strand breaks, then the cable weakens, the next one goes, all hidden within the changer.

    Changing a cable is not too difficult (just tedious trying to get it round to the outer when you have the hidden gear cable versions) and it will save you the grief of the risk of a changer damaged by impossible to extract cable.

    How long to wait to change a cable? I've had a 7900 DA rider wear one out in 6 month, second chain so say 3000 miles, my Tiagra cable went after 9 months - 3000 miles again, got a Ultegra on the stand now with two strands broken in the cable which probably had new cables with the last chain change, chain extremely overworn so I am guessing another 3000 miles. If you don't change gear much then they won't wear much but I am an enthusiastic gear changer.

    So when you have your bike serviced, insist that they change the inner cable for the rear changer if you've done more than a couple of thousand miles since it was last changed. The cable costs them pennies (you more!) but will save you grief.

    BTW, a problem with internally routed cables is that when fitting new cables, giving them a good, string tug is normally the way a mechanic makes sure they are bedded in properly. With internally routed cables there is nothing to get hold of so it is really hard to get enough pull on the cable to bed in the fittings. Over-shifting (e.g. with an overly tight low adjustment screw on the rear derailleur or an overtight cable) is one solution to try and get tension in the cable to force the cable ends home.
    Agree with this, my Ultegra 6603 rear mech cable cable has snapped inside the shifter twice in 15,000 miles,first one went at 6500 mi and the second at 14,500 miles so an ave life of 6-7000 miles then, and i noticed having to tune the gears much more than normal in the period before they snapped, luckily the last time it snapped at home during a pre ride check, the previous ride had been 86 miles and i had to adjust the gears during the ride, now carry a spare cable as being pre cable under bartape shifters its a doddle to fit a new cable if you can fish the broken cable/nipple out, probably worth changing the cable at 5000 miles though in view of my experience.
  • ugo.santalucia
    ugo.santalucia Posts: 28,301
    Crickey, I'm not saying it'll happen over night. I'm talking months to a year of leaving it on the big ring when not in use. Whether it's a myth or not, surely it can't hurt can it?
    :roll:

    Using the same metrics, the wheels I have hanging should be oval by now... :wink:
    left the forum March 2023
  • Bozman
    Bozman Posts: 2,518
    Can't say that I've ever thought about cable stretch, I've always kept the chain on the large chain ring and the summer bike is like that all winter with no issues at all.
  • kettrinboy wrote:
    Agree with this, my Ultegra 6603 rear mech cable cable has snapped inside the shifter twice in 15,000 miles,

    I'm also running 6603 and have had the same happen to me in - once on the front derailleur and once on the rear. I think it is worth slackening off the cable and thoroughly lubing the outer every now and again. In doing this, it is easy to check whether the cable has started fraying at the shifter end. Mine failed out on the road both times, but fortunately at locations where I could still get home. I buy spare inners now to replace regularly, but I suspect the cause is more down to lubrication than anything else.