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DI2 syncro shift on 30 sprocket

kingrollokingrollo Posts: 3,147
edited December 2018 in Road general
Not really a problem - but just after a bit of advice.

I am very impressed with my DI2 - love the way it hops on and off the big chainring ...well most of the time -

Due to a heart condition, being asthmatic, I opted for easy gears 50-34 - with a 30 tooth rear cassette - the problem is as I am going down the gears going up hill , when it switches from the big chairing to the small via syncro there is quite a lag before the gears are engaged (would latency be the word here ?) is this a shortcoming of the 30t cassette - or is it something I need to adjust ?

Posts

  • StillGoingStillGoing Posts: 5,153
    Have you set the speed of the shifts to fast? Presumably you aren't using the short cage rear derailleur? I use 36/28 and don't suffer any problems with speed of shifting. I've set my shift speed to fast using Etube.
    I ride a bike. Doesn't make me green or a tree hugger. I drive a car too.
  • kingrollokingrollo Posts: 3,147
    philthy3 wrote:
    Have you set the speed of the shifts to fast? Presumably you aren't using the short cage rear derailleur? I use 36/28 and don't suffer any problems with speed of shifting. I've set my shift speed to fast using Etube.

    I haven't touched anything. The shop set it all up for me. I was advised that a 30 cassette was the largest I could have on the short cage derailleur.
    I haven't checked it out on etube yet. I am presuming the shop just put in the defaults.
  • FWIW, i stopped using syncro shift after it caused an unexpected downshift to the inner ring as i was downchanging coming to a stop at aset of lights - that resulted in a dropped chain that jammed between the frame and the shainset that i had to loosen the chainset to release - it was the unexpected downshift that caused the drop - nothing else.

    i just manual shift front / 3 gear multishift on the rear now with no problems
  • StillGoingStillGoing Posts: 5,153
    moonshine wrote:
    FWIW, i stopped using syncro shift after it caused an unexpected downshift to the inner ring as i was downchanging coming to a stop at aset of lights - that resulted in a dropped chain that jammed between the frame and the shainset that i had to loosen the chainset to release - it was the unexpected downshift that caused the drop - nothing else.

    i just manual shift front / 3 gear multishift on the rear now with no problems

    That's obviously a set up issue. I have no such problems with mine set to synch shifting.

    OP, try adjusting the B screw as the short cage derailleur should cope with a 30 tooth sprocket max.
    I ride a bike. Doesn't make me green or a tree hugger. I drive a car too.
  • kingrollokingrollo Posts: 3,147
    philthy3 wrote:
    moonshine wrote:
    FWIW, i stopped using syncro shift after it caused an unexpected downshift to the inner ring as i was downchanging coming to a stop at aset of lights - that resulted in a dropped chain that jammed between the frame and the shainset that i had to loosen the chainset to release - it was the unexpected downshift that caused the drop - nothing else.

    i just manual shift front / 3 gear multishift on the rear now with no problems

    That's obviously a set up issue. I have no such problems with mine set to synch shifting.

    OP, try adjusting the B screw as the short cage derailleur should cope with a 30 tooth sprocket max.

    It does cope - its just that as it coming down of the big chaining when the elevation goes upwards there is quite a delay , its not as crisp as other changes or a manual shift onto the smaller rings.
  • zeeezeee Posts: 99
    I noticed this. It just takes a second or so to move to the small chain ring and down a few cogs on the cassette. I have mine on the fastest setting. I think you have to expect some sort of delay for it to sort itself out as it's never going to be seamless.

    I run 11-28 so nothing to do with your set up.
  • philthy3 wrote:
    moonshine wrote:
    FWIW, i stopped using syncro shift after it caused an unexpected downshift to the inner ring as i was downchanging coming to a stop at aset of lights - that resulted in a dropped chain that jammed between the frame and the shainset that i had to loosen the chainset to release - it was the unexpected downshift that caused the drop - nothing else.

    i just manual shift front / 3 gear multishift on the rear now with no problems

    That's obviously a set up issue. I have no such problems with mine set to synch shifting.

    OP, try adjusting the B screw as the short cage derailleur should cope with a 30 tooth sprocket max.
    It is set up fine buy It was a one off chain drop caused by an unanticipated shift from big to small that I wasn't expecting as I back pedalled at slow speed coming to a stop at a set of lights.
    It happened once. & it won't happen again for me as I chose to disable the synchro shift.
  • StillGoingStillGoing Posts: 5,153
    moonshine wrote:
    philthy3 wrote:
    moonshine wrote:
    FWIW, i stopped using syncro shift after it caused an unexpected downshift to the inner ring as i was downchanging coming to a stop at aset of lights - that resulted in a dropped chain that jammed between the frame and the shainset that i had to loosen the chainset to release - it was the unexpected downshift that caused the drop - nothing else.

    i just manual shift front / 3 gear multishift on the rear now with no problems

    That's obviously a set up issue. I have no such problems with mine set to synch shifting.

    OP, try adjusting the B screw as the short cage derailleur should cope with a 30 tooth sprocket max.
    It is set up fine buy It was a one off chain drop caused by an unanticipated shift from big to small that I wasn't expecting as I back pedalled at slow speed coming to a stop at a set of lights.
    It happened once. & it won't happen again for me as I chose to disable the synchro shift.

    Not a problem with the system then but user error. It won't down change on its own, so you obviously selected a lower gear on the rear and made the mistake of back pedalling as the front derailleur changed rings.
    I ride a bike. Doesn't make me green or a tree hugger. I drive a car too.
  • philthy3 wrote:
    moonshine wrote:
    philthy3 wrote:
    moonshine wrote:
    FWIW, i stopped using syncro shift after it caused an unexpected downshift to the inner ring as i was downchanging coming to a stop at aset of lights - that resulted in a dropped chain that jammed between the frame and the shainset that i had to loosen the chainset to release - it was the unexpected downshift that caused the drop - nothing else.

    i just manual shift front / 3 gear multishift on the rear now with no problems

    That's obviously a set up issue. I have no such problems with mine set to synch shifting.

    OP, try adjusting the B screw as the short cage derailleur should cope with a 30 tooth sprocket max.
    It is set up fine buy It was a one off chain drop caused by an unanticipated shift from big to small that I wasn't expecting as I back pedalled at slow speed coming to a stop at a set of lights.
    It happened once. & it won't happen again for me as I chose to disable the synchro shift.

    Not a problem with the system then but user error. It won't down change on its own, so you obviously selected a lower gear on the rear and made the mistake of back pedalling as the front derailleur changed rings.
    i never said it was a "problem with the system" and i accept it was user error, but the system unexpectedly changed front chainring when i wasn't expecting it - which caused the user error. on that basis i don't like it and don't use it.

    i don't expect to have to look at my RD to see when it is abour to shift my FD as i downshift into an easier gear as I am coming to a stop at an uphill set of traffic lights and stop RD shifting so ithe FD doesn't auto shift. IMO that experience was enough to put me off using the Syncroshift function it - which is a pity ans i found it quite good in all other aspects.
  • The OPs issue is exactly why I DONT use Synchro Shift...I felt it made its own mind up rather than doing what it was alleged to do..it seems really complicated to set up too..Ive had the D Fly, for the bluetooth winless app, and also now the tube project, neither made it any easier.. I just stick to single, crisp one sprocket changes....I know...I'm a luddite, but hey, it works for me!!
  • zeeezeee Posts: 99
    I find it really useful. I have mine set so if I try to go to the biggest sprocket (28) whilst on the big chain ring it shifts to the small chain ring and moves down a few cogs on the cassette. This gives me a few extra gears on hills a prevents me having to switch chain ring in the same sprocket causing me to spin up. It also prevents cross chaining.

    I do however have to keep an eye on my cassette but I'm hoping to get a wireless unit so I can see what gear I'm in on my garmin.
  • stueysstueys Posts: 1,332
    Syncro is nice, I like it. I do think you need the d-fly unit if you use it though, with that you get both visual and audible notification on your garmin when the next shift will result in a front chain ring move. I'm not sure I would use without that for the reasons people have posted above.
  • StillGoingStillGoing Posts: 5,153
    I use it without problem. I always have a fair idea what gear I'm in on the cassette. Mine is set up so when the front changes, it changes up or down 3 on the cassette. Similar to others, if I'm in the big ring and about to go into the largest sprocket, the front will change automatically and the rear goes up 3 sprockets. Works the other way if I'm in the small ring and about to go into the 13 tooth. Front changes to the big ring and the rear drops 3 sprockets. Never given me any issues.
    I ride a bike. Doesn't make me green or a tree hugger. I drive a car too.
  • keith57keith57 Posts: 162
    Works fine here. Noticed the other day that I get a warning on my Garmin screen that the next change will change the big ring!

    One of my bikes has mechanical DA and the LBS told me a previous customer had tried the Ultegra 11-32 cassette and it worked fine. So I have one of those on too now. It’s great and works fine on my mainly wet weather bike. So that’s 2 more teeth than Shimano says the short cage DA is supposed to be able to cope with. I’d hazard a guess the Di2 version would work the same?
    http://www.fachwen.org
    https://www.strava.com/athletes/303457

    Please note: I’ll no longer engage deeply with anonymous forum users :D
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