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Klonking sound when back wheel turns

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by nina, Mar 17, 2013.

  1. First of all, I am going to give my bike to the shop this week. So I like to know how severe it is (as I have to ride my bike to the shop) and it's also good to know how much money this is going to cost me to fix!



    Since last week Saturday my bike does a clear, loud 'klonk' when turning the back wheel. It did it the first time while I pushed it, but I wasn't able to reproduce it enough to make other people believe that there was actually something wrong. It hasn't really been showing until a week later. But even then it was not often enough (I couldn't make the sound on purpose) so that I wasn't able to ask others to have a listen. That day I rode her a bit on rural roads and after that she started doing it quite often. I had to ride her again today, and now the status quo is as follows:
    When the back wheel is being turned - doesn't matter what gear, whether under load or not (does it when turning it by hand when up on the paddock stand) there is this very loud 'klack'. You can feel that klack. It can happen more or less frequent, I don't think that it depends on how fast I turn the wheel. It happens when it's being turned in either direction (I believe more often when going forwards). It doesn't always happen at the same point. Sometimes it happens more frequent, then it might not occur for a few turns.
    I can't really see anything jumping around. I have the feeling that the sound originates from just to the right of the axis - that would be where the brake is. I had originally thought it might be the chain, as it sounds similar to that, but I can't see the chain jumping around or anything.

    Right now it is really worrying me as it started doing that A LOT since my last trip.

    The bike in question is a 1989 Honda Spada. On the day she did that sound the first time, I had something done to her front, but not her rear. Some person did though grab a screw driver and wriggle the chain up and down quite a bit (in order to show me the chain slack) - I wouldn't have thought that that would cause any issues.

    Any pointers are appreciated, would be nice to know what's going on before giving her away!
     
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  2. Really loose chain with a tight spot?
     
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  3. Chain has correct slack/tightness. I couldn't find a tight spot either when inspecting it just before I posted.
    Chain had been my suspect as well though. It's not that old either (8000 km old and cleaned and lubed regularly).
     
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  4. Check there is nothing stuck under the mudguard / chain guard / front sprocket cover.
     
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  5. Yup, sorry, should have mentioned that. Was the first thing I did when I arrived home: I gave the chain a good clean, taking not only the mudgard but also the front cover off and looking for stones or other stuff. Nothing there, sound's still happening.
     
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  6. Ruling out the chain on what you've said on that, roughly in order of what comes to mind from your description: Wheel bearings/bushes or some sort of cush drive problem could fall under these symtoms if it's definitely coming from around the rear wheel hub itself. Another outside possibility easily ruled out is checking that the bolts holding the rear sprocket are all tight (not just feeling by hand, but with a spanner or socket).

    Is the rear brake disc or drum on these? If it's disc, take a torch if need be and check the rear pads for wear and if they're sitting level against the disc. If it's drum, then there's a handful of bits inside as well as brake shoe wear that could be worth a look.

    Checking for any movement in the wheel, raised off the ground, if you try to move it sideways as well as back and forth (without turning it at the same time, then rotate a bit then try again a few times) could help to suggest or rule out one thing or another.


    Also, when in gear (again wheel off the ground), is there much more play from trying to rotate the wheel back and forth than what you can see to be due to the normal bit of slack in chain?

    Also somewhat on the outer, but possible, is some sort of front sprocket woe like a missing tooth, overall wear, or loose mounting bolts that's being transmitted to the rear hub via the chain and seemingly coming from there due to sympathetic resonance or some other such mechanical/acoustic subterfuge.

    You mention that it happens whether under load or not. Does that mean also while turning the wheel in neutral?

    At this point, it does sound quite like it could be a bearing issue.
     
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  7. Great thoughts there Wayned, very much appreciated!
    Just checked the bolts of the rear sprocket with a spanner: they look pretty tight to me.
    It's a disc brake. I remember being shown twice how to check whether the pads are thick enough, but to be honest, I don't know. They do have a certain thickness, but I don't know whether enough. They are sitting right at the disc, doesn't seem to be at an angle or anything... Unfortunately I'm not very helpful here.
    Doesn't move sideways. Forward/backward movement seems normal..
    I can't see any missing teeth, nor anything else that could be interfering with the chain. It's a good thought though that something would be transmitted from the front and therefore only seems to be coming from the axle.
    Yes, it does mean when turning the wheel in neutral. Right now it is only happening when turning the wheel forward (I mean as in the bike would be rolling forward), but not at all when turning backwards. When I got off the bike a few hours ago, it did also occur a couple of times when turning the wheel backwards. It also is now not happening that frequent anymore, as if it's somehow recovering by not being moved. Not sure whether that means anything?

    Bearing issue?
     
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  8. I'd too would go with the 'Wheel bearings'.

    If your chain is in good condition and the rear sprocket has good teeth (not arched over; therefore grabbing the chain when rolling forward)... I'd look at the rear wheel bearings first.

    Not sure if that model has a 'cush-drive' system (I'd imagine it does) , however, I'd replace the wheel bearings (and sprocket carrier bearing).
    Bearing are easy to replace (y) and cost you around $25. (just google it... youtube has heaps)

    let us know what it turns out to be.
     
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  9. Hmm... what kind of coincidence would that be, as just last week there was something done on the front bearings?

    I'd definitely love it, if it wasn't anything major. She needs due for her major service, so if it's something that only easy on top, it would be amazing!
     
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  10. #10 Wayned, Mar 17, 2013
    Last edited: Mar 17, 2013
    I mean forward/backward against the the axle, without rotating, to check for any play at the rear axle (or swingarm too, for that matter) of the sort that checking sideways movement also looks for. In that case there also shouldn't be any notable movement at all.

    Your systematic approach seems to have ruled a lot out, barring something a bit sneaky that might be difficult to spot (or something completely else besides). Bearings seems to still be in the running, though, since there could still be a problem even if everything else feels taut.

    That will probably need someone with the knowhow to check it out in person, barring pulling the wheel off and looking inside. Most bearings on bikes can be bought from regular bearing places, and often much more cheaply than ordering as a bike shop part.

    If you haven't already, see if you can find an online workshop manual and parts listing for your bike. It could be a relatively simple and cheap enough excercise to be worth doing anyway.

    *Yet another minor possibility comes to mind - the rear disc, it's carrier (whatever means of them being attached, like fixed, floating, or some variation) and if everything there is also in order. It seems unlikely though, given the irregular occurrence of the problem.

    That's about as much as I can think of, unless or until someone more qualified offers other checks you might be able to do. *EDIT* Looks like Dobbo has already done just that.
     
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  11. Thanks guys. I'll see what the mechanic that says. Hopefully they aren't too busy, I need my bike!
    Hate having to give her into someone elses hands :cry:
     
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  12. I've had something like this happen once. The axle nut had come loose and the back wheel was sliding backward and forward a few mm.
    Also check brake caliper mounting and chain guard.
     
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  13. IM GOING WHEEL BEARINGS... BEFORE I READ THROUGH EVERYTHING... DIDN'T YOU MENTION SOMETHING ABOUT A NOISE IT WAS MAKING LAST WEEKEND AN STREETY UGGESTED YOU GET IT OFF THE GROUND TO CHECK THE BEARINGS?

    oops caps lock, sorry wasn't shouting
     
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  14. ok ive read enough. i'd say the bearign has terminated itself and the klack sound it when one bearing rolls over part of another one...
     
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  15. Yep, streety did suggest lifting her up and checking the bearings. Something I looked at in the manual and then put to the side thinking 'I can't do that!'

    Dropped her off this morning. Mechanic wasn't there yet, I'm sure he would've been able to say something right away (I'm sure anyone who knows anything about bikes and heard that sound life could have) but I didn't have the time to wait for him.
    Unfortunately I made it even worse yesterday! On my way to the shop I was sooooooo careful as it was making that sound VERY frequent and I even imagined a slightly wobbly back wheel. But that could have also just been me freaking out over my poor little bike being broken?

    Anyhow, awaiting a call that will bring news. Hopefully not too bad news *fingers crossed*
     
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  16. Just got a call, it was the bearings. Something bearing part in wrong place and therefore making klack sounds when wheel was spun. Dunno. All I know is that I'm so happy, I wanna give the guy a huge hug.
    Oh and next time @goddie and whoever else was there at the spanner day: when I say my bike is making a sound it shouldn't then it is really making a sound it shouldn't. It's not just me knocking against the peg while pushing the bike :p
    Still find it a strange coincidence that just after the head stem bearings (or whatever they are called) were making trouble, the bearings in the back started causing trouble. Next time I have issues with anything at the front, I will change the opposing part on the back as well!
     
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  17. Not to be argumentative, but, not at all. On an older vehicle for which you haven't been responsible for all its maintenance, anything's possible.
     
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  19. Paul, I just started having problems with responding to converstations such as this, as you can see my previous entry is empty, when I click on reply, I dont get the screen to start typing my response, allI get showing is the 'post your reply line, this only just started to happen this morning, can someone have a look at this please? thanks
    Godwin
     
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  20. True. The front bearings simply needed some tightening (and greasing), the bearings themselves were still OK. The rear bearing on the other hand was f*cked and needed urgent replacement.
    Now that I've owned her for almost a year, I should slowly be getting up to date with maintenance on all those parts, right? Well at least until the next thing happens ;)
    It is kinda nice though, I'm learning as I go along. I know now what the symptoms of worn out rear bearings are. It is an old bike, parts do unfortunately wear out/vibrate lose over time. I'm always surprised when it feels as if the bike were falling apart underneath me, but it's nonetheless a relatively easy fix. I should learn more about bike mechanics, find it quite fascinating. If only I had more patience!
     
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