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Jumping gears since changing wheels

perfectmarkperfectmark Posts: 117
edited September 2018 in Workshop
Hi, I am hoping someone has an idea of what could be causing this as it makes no sense to me.

I recently got some new lighter wheels for my 2014 Roubaix. But when I went out on my first ride, I noticed that it didn't shift properly anymore. Tried reindexing, but couldn't make it any better. I thought I might of bent the rear derailleur when installing the wheel (it was looking a bit worse for wear anyway), so I replaced the Sora 3500 rear derailleur with a Sora R3000 GS (so I have the option of using a 11-34 cassette in future). Also replaced the chain at the same time. Both the new and old set of wheels are 11 speed, but am using the same spacer.

Now the bike shifts OK, but the gears keep skipping when I am putting the power down. This only happens when on the small front chainring, not the large. I have tried messing with the B tension screw and double checked the chain is the same length as before.

So the next thing I tried was replacing the cassette (replaced a 11-32 Shimano XT one with a standard SRAM 11-32), but made no difference.

My next thoughts are I damaged the chain when installing (it was a Shimano one with a pin and have only used quick link ones before). I could also look at changing the gear cable or the small chainring, but don't see how that would make much of a difference (I can see on the stand that the chain is jumping on the rear cassette). So don't know if anyone has any other ideas?

Posts

  • cooldadcooldad Posts: 32,601
    Messing about doesn't help. Disconnect everything and start from scratch with the limit screws then the indexing.
    Parktools site below might help.
    I don't do smileys.

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  • cooldadcooldad Posts: 32,601
    And check the chain is threaded the right side of the tab on the mech cage.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • SJH76SJH76 Posts: 191
    Your old wheels freehub is most likely 9-10-11 speed if you're using Sora. Since new Sora R3000 is 9sp and the new wheels are probably 11sp only I see a compatibility issue even using a spacer wheel new freehub isn't designed for use with 9sp. You may at the very least need a different spacer to fix things
  • jgsijgsi Posts: 5,029
    cooldad wrote:
    Messing about doesn't help. Disconnect everything and start from scratch with the limit screws then the indexing.
    Parktools site below might help.

    Always the best advice.
    Problems like these usually have a very simple solution, when you have detected the source of the said problem.
    Check as best you can compatility with the components you are using.
    As a complete guess, I might have stuck another 1mm spacer on... do you have 1?
    Bike fettling usually needs a lot of boxes full of random sh it... otherwise just give it to a LBS.
  • whyamiherewhyamihere Posts: 7,508
    SJH76 wrote:
    Your old wheels freehub is most likely 9-10-11 speed if you're using Sora. Since new Sora R3000 is 9sp and the new wheels are probably 11sp only I see a compatibility issue even using a spacer wheel new freehub isn't designed for use with 9sp. You may at the very least need a different spacer to fix things
    Ignore this, it's just wrong.
  • Vino'sGhostVino'sGhost Posts: 4,129
    
    
    whyamihere wrote:
    SJH76 wrote:
    Your old wheels freehub is most likely 9-10-11 speed if you're using Sora. Since new Sora R3000 is 9sp and the new wheels are probably 11sp only I see a compatibility issue even using a spacer wheel new freehub isn't designed for use with 9sp. You may at the very least need a different spacer to fix things
    Ignore this, it's just wrong.

    Agreed with why am i here
  • SJH76SJH76 Posts: 191
    whyamihere wrote:
    SJH76 wrote:
    Your old wheels freehub is most likely 9-10-11 speed if you're using Sora. Since new Sora R3000 is 9sp and the new wheels are probably 11sp only I see a compatibility issue even using a spacer wheel new freehub isn't designed for use with 9sp. You may at the very least need a different spacer to fix things
    Ignore this, it's just wrong.

    11 speed wheels and 9 speed mech and you're wondering why it's not working. Explain why it's wrong please and what the real solution is since you didn't actually do so
  • svettysvetty Posts: 1,904
    A 9 speed cassette will work fine on an 11speed freehub providing it has the correct - 1.85mm - spacer fitted. You shouldn't need any other spacers - assuming the hanger isn't bent.

    @ OP it might be that the cable is sticking - try changing the section of outer from the stop to the mech. If this doesn't work make sure that the inner cable isn't fraying - might be worth fitting a new inner cable anyway.
    FFS! Harden up and grow a pair :D
  • SJH76SJH76 Posts: 191
    Svetty wrote:
    A 9 speed cassette will work fine on an 11speed freehub providing it has the correct - 1.85mm - spacer fitted. You shouldn't need any other spacers - assuming the hanger isn't bent.

    @ OP it might be that the cable is sticking - try changing the section of outer from the stop to the mech. If this doesn't work make sure that the inner cable isn't fraying - might be worth fitting a new inner cable anyway.

    I did say a different spacer. But was dismissed as wrong.
  • Thanks for replying, the old set of wheels were 11 speed, the new set are also 11 speed (Cero AR24), they both say 9/10/11 speed compatible. I tried using the 9 speed spacer for my last wheels and the one from the new set, but didn't make any difference. (They are both the 1.85mm ones). But I guess I can look out the 10 speed spacer and give that a go.

    I have a spare gear cable, so will probably end up changing it over the weekend and setting everything up again from scratch.
  • svettysvetty Posts: 1,904
    Thanks for replying, the old set of wheels were 11 speed, the new set are also 11 speed (Cero AR24), they both say 9/10/11 speed compatible. I tried using the 9 speed spacer for my last wheels and the one from the new set, but didn't make any difference. (They are both the 1.85mm ones). But I guess I can look out the 10 speed spacer and give that a go.

    I have a spare gear cable, so will probably end up changing it over the weekend and setting everything up again from scratch.
    The 10 speed cassette spacer is only 1mm thick and isn't the correct one for a 9 speed cassette on an 11 speed freehub.
    If you cannot get the indexing to work corectly with the 1.85mm spacer either you have a bent mech hanger or you lack the expertise.
    FFS! Harden up and grow a pair :D
  • A number of assumptions:

    I assume this is a Specialized Roubaix?
    You previously had stock wheels on the bike?
    Your wheels are Quick Release?
    Your new wheels are not SCS compatible?

    If the above is true, carry on, otherwise ignore :-)

    Your bike comes with SCS (Short Chain Stay) compatible wheels. Even though the frame is a standard width, the hub is a few millimeters shorter. No matter what gear you are on, the chain will actually be 5 millimeters in from where the derailleur hanger is. If you look at the hanger you will see that it goes straight down on the outside (as expected). But if you look at the inside of the hanger, it moves in a few millimeters part way down the hanger.

    As a result, when you change your wheels and don't get SCS compatible wheels, the chain will be pushed in by 5 millimeters from where you would expect it. You may be able to get around this by adjusting the limit screws, but you will probably find that the hanger pushes against the edge of your cassette (it did when I change my wheels).

    You simply need to buy a new hanger to convert from SCS to normal wheels, such as the following:

    https://www.ebay.co.uk/itm/Mech-Gear-Ha ... 2749.l2649

    Hanger 146 is the one you need. It is designed to allow people with standard Roubaix frames/SCS wheels to convert to using any wheel. It basically doesn't have the bit on the inside that pushes the chain in.

    I used it to convert my 2015 Roubaix and didn't have to make any adjustments to gears etc.
  • A number of assumptions:

    I assume this is a Specialized Roubaix?
    You previously had stock wheels on the bike?
    Your wheels are Quick Release?
    Your new wheels are not SCS compatible?

    If the above is true, carry on, otherwise ignore :-)

    Your bike comes with SCS (Short Chain Stay) compatible wheels. Even though the frame is a standard width, the hub is a few millimeters shorter. No matter what gear you are on, the chain will actually be 5 millimeters in from where the derailleur hanger is. If you look at the hanger you will see that it goes straight down on the outside (as expected). But if you look at the inside of the hanger, it moves in a few millimeters part way down the hanger.

    As a result, when you change your wheels and don't get SCS compatible wheels, the chain will be pushed in by 5 millimeters from where you would expect it. You may be able to get around this by adjusting the limit screws, but you will probably find that the hanger pushes against the edge of your cassette (it did when I change my wheels).

    You simply need to buy a new hanger to convert from SCS to normal wheels, such as the following:

    https://www.ebay.co.uk/itm/Mech-Gear-Ha ... 2749.l2649

    Hanger 146 is the one you need. It is designed to allow people with standard Roubaix frames/SCS wheels to convert to using any wheel. It basically doesn't have the bit on the inside that pushes the chain in.

    I used it to convert my 2015 Roubaix and didn't have to make any adjustments to gears etc.
    Thanks, that sounds exactly like my problem. Will look at ordering one. :D
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