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  1. #1
    Senior Member rousseau's Avatar
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    Chain rubbing on seatstay

    I squeeze a 130mm rear hub into dropouts with 126mm spacing. Works fine, save for the fact that the chain rubs against the seatstay when I'm in my highest gear. I'm wondering what my options are here? Here are the particulars:

    1986 Bianchi Campione d'Italia
    1997 Record hub
    13-23 9-speed cassette
    48-34 crankset

    Last year one of the guys at the bike shop gave me a washer to jam in there. It worked, but I didn't like the idea of spreading the chainstays that extra millimetre, and the washer made it even more cumbersome and difficult to install the wheel, so I stopped using it. For the longest time I have simply stayed out of my 48-13, but lately I've been riding faster down hills, and would really like to utilize that last cog.

    Two questions come to mind: Is there a more elegant way of moving the cassette away from the seatstay? And does this rubbing indeed happen because I'm putting a 130mm hub onto a bike with 126mm rear spacing?

    Thanks,
    R
    The pleasure is momentary, the position ridiculous, and the expense damnable.

  2. #2
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    How about a bigger sproket on the front instead of the smaller one in rear?

  3. #3
    Old fart JohnDThompson's Avatar
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    Quote Originally Posted by rousseau View Post
    I squeeze a 130mm rear hub into dropouts with 126mm spacing. Works fine, save for the fact that the chain rubs against the seatstay when I'm in my highest gear. I'm wondering what my options are here? Here are the particulars:

    1986 Bianchi Campione d'Italia
    1997 Record hub
    13-23 9-speed cassette
    48-34 crankset

    Last year one of the guys at the bike shop gave me a washer to jam in there. It worked, but I didn't like the idea of spreading the chainstays that extra millimetre, and the washer made it even more cumbersome and difficult to install the wheel, so I stopped using it. For the longest time I have simply stayed out of my 48-13, but lately I've been riding faster down hills, and would really like to utilize that last cog.

    Two questions come to mind: Is there a more elegant way of moving the cassette away from the seatstay? And does this rubbing indeed happen because I'm putting a 130mm hub onto a bike with 126mm rear spacing?

    Thanks,
    R
    If there's a spacer on the non-drive side of the axle, move it to the drive side and re-dish the wheel.

  4. #4
    motovation frankenmike's Avatar
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    Since it rubs on the seatstay(above the cog), perhaps a smaller high gear cog would give enough space above the chain(11 or 12?)

  5. #5
    Great State of Varmint Panthers007's Avatar
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    Maybe removing a link from the chain?
    How do you keep an idiot in suspense?

  6. #6
    Senior Member rousseau's Avatar
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    Thanks very much for the suggestions. I'm learning as I go along. There was indeed a spacer on the non-driveside. I took it off, and put an equivalent spacer on the driveside (the axle is slightly bigger on the driveside, so I couldn't just put the non-driveside spacer onto the driveside).

    So far so good. Two issues have arisen, one potentially critical, one not so for now.

    1. I'm getting a pulse in the sound of the clicking paws as I spin the wheel forward. I did end up taking the freehub off and poking around a bit. Is it possible I didn't set one of the paws correctly?

    2. After removing a space on the non-driveside and adding one on the driveside, I thought I might be able to move the axle over by 1mm as well, but no: the axle has a ridge against which the freehub body comes into contact to hold it in place. It appears that the lateral position of the axle is set in stone. Which is okay, I still have enough protruding on the driveside to engage with the dropout, though it is assymetrical. Doesn't matter, I take it?

    Once I get this pulsing sound figured out I'll set to dishing the wheel. But I'm quite please with my results so far: the chain no longer rubs against the frame.
    The pleasure is momentary, the position ridiculous, and the expense damnable.

  7. #7
    Senior Member rousseau's Avatar
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    Quote Originally Posted by frankenmike View Post
    Since it rubs on the seatstay(above the cog), perhaps a smaller high gear cog would give enough space above the chain(11 or 12?)
    Garsh...I think you may be right. Last year I went from a 12-23 to a 13-23 in order to get the 18T cog in there which I coveted, and that's when the rubbing started.

    Sheesh, maybe I should just move on to 10-speed and use 12-23 cassettes? If so, I'd probably be best off switching the spacers back to where they were!
    The pleasure is momentary, the position ridiculous, and the expense damnable.

  8. #8
    Senior Member rousseau's Avatar
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    Having checked my ride log, I found that last year I mentioned that the chain was rubbing against the frame in the 12T cog. So it turns out that it really is a problem of spacing on the axle when squeezing a 130mm rear wheel into a space meant for a 126mm wheel.

    As for the first issue I mention two posts above this one, my guess is the pulse I was hearing had to do with overtightening the locknuts. I've since adjusted everything perfectly, and there's no more pulse.
    The pleasure is momentary, the position ridiculous, and the expense damnable.

  9. #9
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    The locknut needs to stand 3-4 mm proud of the outboard face of the smallest cog in order to for the chain to stay clear of the seatstay. When you shift to larger cogs, the chain has to tilt outward for an instant to climb the cluster. If the chain is too close to the seatstay the edge of the outer link plate will catch on it as it tilts, even if it runs OK without rubbing when it is seated vertically on the outer cog. This effect is most pronounced when you shift two or three cogs up the cluster at once. The effect is attenutated, but not eliminated, by chains with chamfered edges on the outer plates.

    It's worth fussing to get this measurement in this range (rather than just accepting what you get with the spacers you happen to have on hand) because if you allow more gap than this minimum, it locates the cogs farther to the left than necessary, which increases the asymmetry of the wheel and weakens it. Also, as you have found out, you may run out of axle on the non-drive side and not have enough to engage the dropout properly.

  10. #10
    Senior Member rousseau's Avatar
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    Thanks very much for your thoughtful and articulate post. I am indeed a bit nervous about having had to dish the wheel such that the cassette is now positioned a further 1 and 1/2 mm inward. I tightened and loosened the driveside and non-driveside spokes by about a 1/2 turn, respectively. This has made the non-driveside spokes looser than I might like, and there is still room to tighten the driveside spokes, so I may tighten the tension for all of them.

    EDIT: I just ran down to the basement to actually measure the clearance between the smallest cog and the dropout. 3-4 mm is standard, you say? Well, it now measures 4 mm, which means that prior to my adjustments it was at 2 1/2 mm. The inference here is that said original clearance is standard for modern-day frames with spacing of 130mm, but not for frames from the 1980s with 126mm spacing. No?
    Last edited by rousseau; 02-22-09 at 07:55 PM.
    The pleasure is momentary, the position ridiculous, and the expense damnable.

  11. #11
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    ^^ Thanks. The dropout spacing itself has nothing to do with the required chain clearance, but the narrower chains required by the 9- and 10- cog setups that use the 130mm spacing may get by with a tiny bit less breathing room. Also, the smaller the tooth jumps between adjacent cogs, the less the chain has to tilt outward to climb the cluster. Cogs 3 and 4 on a 9- or 10- speed will be only a few teeth bigger than the smallest; in contrast, two cogs over on a six-speed freewheel is going to be 3 or 4 teeth unless it's a corncob, so the chain sweeps out more outward tilt as it shifts.

    On my Record 10-sp. cassette, the outer face of the smallest cog (13T, not 12 like yours) is still the same 3 mm inboard of the outer face of the locknut -- it's not really a locknut on this type of hub but let's call it that so we don't get lost. The chain runs and shifts without grazing the stay of my steel Pinarello that's about the same age as your Bottechia. (The lockring holding the cassette on sticks out another millimetre or so beyond the cog face and seems to be just a hair's breadth clear of the dropout but the chain doesn't care about that of course.)

    The 3-4 mm clearance I quote is what I use when I'm modifying older hubs to use 7-speed freewheels. (Freewheels, for all their faults, do allow mixing and matching ad lib. Freewheels came in different widths and spacings so you had to build your hub to comply with the one you had.) I'm puzzled that a 9-speed hub built to work with its own 9-speed cassette should have come from the factory with inadequate clearance. And I know it has to be a 9-speed hub because 9-sp cogs won't fit on an 8.

    Any chance that one or more of the spacers between the cogs is too wide? I don't know 9-speed Campy very well except that Veloce cassettes have 9 separate cogs with amber resin spacers. If yours is built this way, are all the spacers the same colour? If a black 8-speed spacer or two crept in there, you would still be able to screw on the lockring but it would push the outer cog out far enough to rub.

    The other possibility is that the seat-stay on your old frame was not shaved down enough for chain clearance just above where the dropout is brazed into it. This is a situation where I'd really love to see the bike and watch the chain dance. Any chance your location in Southern Ontario is near Toronto or Hamilton? Once the weather warms up we might run into each other on the road somewhere.

    Best.
    Last edited by conspiratemus; 02-22-09 at 09:19 PM. Reason: typos.

  12. #12
    Senior Member rousseau's Avatar
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    Okay, so there goes my theory!

    I cannot say that my 1997 Record hub came from the factory with insufficient clearance for a 9-speed hub because I am at least the second owner of the hub, and could even be the third or fourth. I bought the Record hub in a tubular wheelset last year, which I subsequently switched over to clinchers. I don't actually know what type of frame the previous owner had, as that never came up. He said the wheelset had been left sitting for a number of years as he himself had switched to clinchers long previously. The actual transaction was made via a third-party in any case, so I never saw the previous owner nor did I have the concomitant opportunity of seeing his bike or bikes or chatting about the history of the wheelset in person.

    Having said all that...maybe the previous owner did indeed add a spacer on the non-driveside and remove one from the driveside. I haven't found any detailed technical specifications for that vintage of hubs on the web, so I wouldn't know what the standard locknut spacing would be. All I can say is that the configuration when I received it was this: there was a 1 1/2mm spacer in between the two locknuts on the non-driveside. Would it come from the factory with a spacer? Doesn't seem plausible, when you think about it.

    Nevertheless, the protrusion of the axle is now asymmetrical, which you wouldn't expect. So I'm stumped.

    The cogs and amber resin spacers of the Veloce 9-speed cassette which I purchased from Probikekit last year are all standard, so no, the cassette is definitely not too wide. Shifting is precise, which it wouldn't be if the spacing weren't just right.

    Maybe I should take some close-up photos of the seatstay and post them here? In lieu of running into each other on the roads, I mean. I'm in Stratford, and only venture as far as Waterloo when the winds are easterly and I have the time for a good long ride. I've never ridden as far as the Molson Golden Horseshoe, though I'm originally from that area (Hamilton).
    The pleasure is momentary, the position ridiculous, and the expense damnable.

  13. #13
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    This is getting interesting, almost forensically so. As well as the seatstay, photos of the hub out of the frame with the cogs removed that shows the arrangement of spacers and locknuts on both ends of the axle would also be helpful. And also a photo with the cogs and lockring in place that shows the protrusion of the locknut as you measured it. Then maybe we can find some catalogue exploded views to compare them to.

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    Here is what it is supposed to look like:
    http://www.campagnolo.com/repository...spares97-B.pdf

  15. #15
    Senior Member rousseau's Avatar
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    Thanks for the link to that PDF. Here are some photos of my back end.

    1. Does this look like normal clearance between chain and frame to you?


    2. It's a bit rusty, as you can see!


    3. Driveside.


    4. Non-driveside. I removed a 1 1/2mm spacer from between the two locknuts. And contrary to my supposition above, the exploded view below suggests that the hub originally included a spacer.


    5. The protrusion of the axle is now asymmetrical. This lends further creedence to the theory that a spacer was there when it left the factory.


    6. Cogs removed.


    7. The pertinent page of the spares catalogue via your link. I'm quite sure now that the spacer I removed is FH-RE016T. Which begs the question, then: why was my chain rubbing against the frame in the first place?
    Last edited by rousseau; 02-23-09 at 10:45 PM.
    The pleasure is momentary, the position ridiculous, and the expense damnable.

  16. #16
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    OK....
    1) > "Does this look like normal clearance between chain and frame to you?"
    No, there is excessive clearance between the chain and your dropout. You took this photo after inserting an extra spacer on the drive end of the axle, right? 2 mm clearance from the outer *edge* of the chain should be adequate, which is what you get with 4 mm of space between the cog face and the dropout. Any more than that and you end up with excessive asymmetry and a weaker wheel, as you alluded to when you redished the wheel by a half-turn on each spoke. That's a lot.
    Is that a 9-speed chain like it should be?

    2) Yes, it's rusty. I'm sure it wasn't rust or scale or other foreign-object debris that was rubbing on the 13T cog that started all this...

    3) Your locknut on the drive side is sticking too far out beyond the cassette lockring. The locknut wants to be no more than 4 mm outboard of the outer cog face, so when you put a lockring on, the locknut will be just barely peeking out above it. The reason it's sticking so far out is because you moved the spacer from the non-drive side to the drive side, correct?

    4) Indeed you did and indeed it did. To keep our terms straight, it is not two locknuts over there on the non-drive side but instead it's one locknut (FH-RE011) jammed down onto one bearing cone (FH-RE107.) Universal practice is to provide a washer between a locknut and whatever that locknut is supposed to lock, in this case the adjustment of the bearing cone against the balls in the hub. The washer on Campy hubs will have a little dog on the inside diameter that engages the slot cut lengthwise in the axle, which prevents the washer from turning (and then turning the cone, disturbing the adjustment) when you tighten the locknut down against it. (Although in practice, that's what cone wrenches are for.) Any additional spacers required to make the OLD come out right (130 mm in this case) go in here as well. The 8-speed Record hub I have in front of me, same vintage and design as your 9-speed, has an aluminum spacer as well as a black steel dogged washer between cone and locknut. The steel washer being the same colour as the locknut and cone, I can't tell from your photo 4 whether the washer is still there, but the aluminum spacer definitely is not.

    So I would put that aluminum spacer back on the non-drive side. Reinstall the cogs. Look again at the relationship between the drive-side locknut and the cassette lockring: it will be so close to flush that you will think, "Nah, that'll never fit," but if you have 4 mm between *cog face* (not lockring) and locknut, you are according to spec.

    Install your wheel and look again to see where the chain rubs. (Open the rear brake wide so you don't have to re-dish the wheel yet and can concentrate on watching the chain.) Since the hub was sound the way it was, the problem has to be in the frame. I confess to being very unsatisfied with this non-explanation but I think it's the best I can do without seeing the bike. At least we've established that there is nothing wrong with the hub (or at least, won't be, once you put the spacer back where it belongs.)

    I think you should cold-set (i.e., "bend") the frame out to 130 mm, if for no other reason than you are going to be doing a lot of trial and error to get this right, and jamming the wheel into a too-narrow spacing over and over again is a pain in the butt for you, even if it doesn't hurt the frame any.

    An earlier poster suggested using a 12T small cog. (I erroneously thought you were already using a 12T until I went back just now to re-read.) Would be an expensive fix, since you would not want to have a 14 -> 12 jump even if you could find an isolated 12T cog instead of buying a new 12-23 cassette.

    Good luck.

    Edit: If you really really have to, you could slip a very thin washer, say 0.5 mm, under the drive-side locknut to scratch out a tiny bit of extra clearance for the chain. This will affect the wheel dish if you are fussy, but probably won't weaken the wheel.
    Last edited by conspiratemus; 02-24-09 at 08:19 PM.

  17. #17
    Senior Member rousseau's Avatar
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    Thanks for the detailed reply. I'll certainly put the spacer back onto the non-driveside and take out a spacer on the driveside to return it to spec. Oh, and I'll put a 0.5mm spacer in there to keep the chain off the frame, as per your suggestion, to see how that works.

    Yes, I'm using a KMC 9-speed chain.

    I used to run a 12-23 on the bike and the chain still rubbed against the frame, so that's not a fix.

    I honestly don't mind taking the wheel on and off, so if cold-setting the frame to 130mm doesn't fix the problem then I don't think I'll bother.

    I guess I've got my work cut out for me!
    The pleasure is momentary, the position ridiculous, and the expense damnable.

  18. #18
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    Thanks to conspiratemus for that excellent tip about 3-4 mm from sprocket face to locknut face, it is a useful complement to the Barnett's manual advice of less than 14mm from derailleur hanger outer face to sprocket face. I've just used it to set up a 7 speed freewheel on a 126mm OLD hub which previously had a wide 6

    I am a strong believer in the benefit of using standardised measurements rather than each one being set up differently per whatever the mechanic thought was ok. We have made great progress in this regard in the 40 years i've been spannering.

    I also concur with your suggestion to cold set the frame, as the dropouts are going to be out of parallel if you just spring the frame open to fit the wheel. If you see the derailleur mechanism move slightly when you're tightening the skewer, then your right dropout is out of parallel.
    Last edited by henrys; 03-28-11 at 05:24 AM.

  19. #19
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    I'm a n00b in this area, but a thought comes to mind: What if you remove a gear from your 9 speed cassette and use a spacer at the very end? I'm sure there is one gear in there you could switch to an 8 speed shifter (or possibly disable one of the clicks on your shifter care of the limit screws?). Again I'm a novice in this area, but that seems to me to be more sensible than messing with the geometry of the frame and possibly messing up an otherwise good bike. Playing self-devil's advocate: I also am not at the level where 5, 7, 9, or 10 speeds makes much of a difference to me except on a mountain bike (34 tooth cog please...) so perhaps my thought process doesn't match your level/goals ...
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