Fitting a Superstar chain device

doublem_1
doublem_1 Posts: 266
edited March 2013 in MTB workshop & tech
I bought a Superstar chain device (like the Blackspire stinger) but haven't yet fitted it. My worry is that the granny ring will rub on the guide (as space is very tight there), so is it common practice to keep the 2.5mm spacer on the drive side between the BB cup and the chain device. My BB Shell is 73mm.

Comments

  • Greer_
    Greer_ Posts: 1,716
    Can't help you with the clearance issue, but there's that many spacers on the bb for a reason - i.e. you can't add more than is needed, as you can't change the axle length of the chainset.
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  • doublem_1
    doublem_1 Posts: 266
    Right ok that makes sense. I certainly won't add any spacers then. Like I said I haven't come to fit it yet so it may/hopefully fit sweet as a nut. :)
  • The Rookie
    The Rookie Posts: 27,812
    No you can't just add a spacer.

    There are sometimes issue with clearance to the granny ring/bolts on 73mm shells as it moves the plate 2.5mm closer.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • doublem_1
    doublem_1 Posts: 266
    The Beginner wrote:
    No you can't just add a spacer.

    There are sometimes issue with clearance to the granny ring/bolts on 73mm shells as it moves the plate 2.5mm closer.

    Whats the plate? And doesn't the chain guide/device replace the spacer? Do you know how this issue is overcome? Sorry for all the questions!!
  • nicklouse
    nicklouse Posts: 50,675
    What cranks?
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  • doublem_1
    doublem_1 Posts: 266
    FSA Gamma crankset.
  • ilovedirt
    ilovedirt Posts: 5,798
    Yeah, 73mm BBs can be a pain in the arse to fit BB mount chain guides to. As long as it's proper BB mount though and not one bolted to an adaptor, you might be alright.
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  • The Rookie
    The Rookie Posts: 27,812
    doublem_1 wrote:
    Whats the plate? And doesn't the chain guide/device replace the spacer?
    The plate is the bit from the BB to the 'device bit' at the other end. Yes the device replaces the one spacer you should have now, hence no spacers.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • *AJ*
    *AJ* Posts: 1,080
    My superstar device wasn't the same thickness as a spacer, It was 2.5mm so I ran the device and a 2.5mm spacer.
  • The Rookie
    The Rookie Posts: 27,812
    Spacers are 2.5mm, maybe you meant the palte was thinner (yes they often are).....maybe you have a 68mm shell? The full story is more helpful than a comment with no context.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • mrmonkfinger
    mrmonkfinger Posts: 1,452
    doublem_1 wrote:
    I bought a Superstar chain device (like the Blackspire stinger) but haven't yet fitted it. My worry is that the granny ring will rub on the guide (as space is very tight there), so is it common practice to keep the 2.5mm spacer on the drive side between the BB cup and the chain device. My BB Shell is 73mm.

    No, the spacer needs to come out, otherwise there will not be enough crank axle for the non-drive side to get a decent purchase on.

    I have a similar setup (FSA crank and external BB) with a 73mm shell and a stinger type guide. I needed to swap the chainring bolts for some lower profile bolts, other than that it all fitted easily enough.

    I guess if you don't have any other bolts, you could always file the heads down a bit.
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  • doublem_1
    doublem_1 Posts: 266
    I think I will need to file the bolts down a bit on the lower ring as it rubs the chain guide. My only concern is that the chain will rub on the guide instead. Will fitting larger rings solve this? I currently have 22/32T.

    Also, if the chain is on the granny ring, the only place the chain can sit on the roller is on the very edge. Is this correct? I did swap out the original washer for a slimmer one to try and bring it inwards a bit.
  • doublem_1
    doublem_1 Posts: 266
    I've almost given up with this. I don't understand how so many people fit these without any issue. I'm contemplating putting the spacer back on just to aleviate the rubbing on the chain guide plate. As I envisaged, after filing down the granny ring bolts, the chain rubs on it. And on the granny ring, the ring sits at such an uncomfortable angle. It doesn't look right.

    IMG_20130327_170825.jpg
  • doublem_1
    doublem_1 Posts: 266
    Would it cause any issues if I added the 2.5mm spacer to stop the chain rubbing?
  • The Rookie
    The Rookie Posts: 27,812
    The cranks may or may not fit right, as you'll have less of the axle inside the other arm.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • *AJ*
    *AJ* Posts: 1,080
    Sorry, what I was getting at was I had a similar issue with my superstar chain device. My BB was also 73mm shell so the device plate should have taken up the same are as the single spacer that should have been there though.

    So to get around the rubbing I still ran a spacer and the chain device on the drive side. It was the only way it would work without the rubbing.

    Ran for 2 years like that with no issues what so ever. Not saying you'll be fine too, but try it. It certainly worked for me.
  • doublem_1
    doublem_1 Posts: 266
    The Beginner wrote:
    The cranks may or may not fit right, as you'll have less of the axle inside the other arm.

    Thanks for the help guys, yes there is less purchase on the non-drive side arm but I think it would be enough, only 2.5mm less. It is the only way around the issue that I can fathom. I really don't understand why these companies sell these things knowing the don't fit.
  • The Rookie
    The Rookie Posts: 27,812
    No problem fitting bikes with 68mm BB or 73mm with single ring, or even many cranks with a 73mm BB as the cranks all subtely differ, also no isse with internal bearing BB's like ISIS....

    Note the mounting plates are usually thinner than 2.5mm so you won't have 2.5mm less axle insertion but the thickness of the plate less.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • mrmonkfinger
    mrmonkfinger Posts: 1,452
    Hmm.

    Well, if you add the spacer (gotta be worth a go), you need to make sure the crank axle is at least level with the outer clamp bolt on the non-drive side.

    YMMV etc.
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  • bennett_346
    bennett_346 Posts: 5,029
    Have to say someone i know had huge trouble with this exact setup and never got it to work properly.
  • doublem_1
    doublem_1 Posts: 266
    mrmonkfinger wrote:
    Hmm.

    Well, if you add the spacer (gotta be worth a go), you need to make sure the crank axle is at least level with the outer clamp bolt on the non-drive side.

    YMMV etc.

    Can't remember if it was when I was fiddling with it, I will check this though when I come to it. Thanks Guys.
  • doublem_1
    doublem_1 Posts: 266
    Thinking that if I don't manage to get it working right, I'll remove the chain guide, remove some links and put on a chainstay protector.

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