does anyone know whether a sloppy chain will cause a vibration in the frame?
I dont think its the engine cos it does it when it's turned off
freewheeling. wheel bearings seem ok no sign of any sideways movement.

Errr, dunno about vibration as such, but they can flap about and rub on things like swinging arms and frame tubes if they're loose enough. Is the sprocket carrier bearing ok? Cush rubbers shagged?

If you've cut the motor and are free-wheeling and getting a noise/feeling then it's got to be chain/wheels/brakes.

A few years ago I saw a programme about bike noise. they had a CB750 IIRC riding past a noise meter at the industry prescribed speed and distance to see how noisy it was. Then they tested it again but cut the motor as they approached the noise meter - it was only about 20% quieter. Most bike noise (race cans apart) comes from the chain and wheels/tyres  

I don't know much about this either Image,  :blush: but wanted to ask FF:



How do you tell if that's the case? What are "cush" rubbers then?

Ok so - cush rubbers




If your sprocket was bolted solidly to the back wheel, the only form of shock absorbtion in the drive train would be the slack in the chain - very rough. So they bolt the sprocket to a carrier plate, and that is keyed into the back wheel via a set of rubber bushes. Next time you're next to another bike, watch the back sprocket when he puts it into gear - it'll move.

Now you don't want too much movement or you're losing power, and soft rubbers are nearly as bad as no rubbers at all. To see if they are worn out, hold the sprocket at a quarter to three and try and move it like a steering wheel - anything more than a couple of mm, or if you can feel free play, and the rubbers want replacing. A good test when you've got the wheel off is how easy does the carrier plate fit back into the wheel. If you have to stamp on it then they're ok. If it falls in they're shagged.


If you can rock the sprocket and carrier plate then the inner bearing is probably shot. These seem to wear fairly quickly as you use a lot of soap and water round there to clean off chain gunge. Easy job. Check the bearing number and buy a new 'un. Pop it into the freezer overnight. Then stick the carrier plate into the oven at 120 deg C for 10 minutes. Hammer old bearing out and pop new one in

Here's the pic  :verysad:

Cheers ff you're a star.
Now I think about it it could be more like a rubbing sensation i'm feeling(sue stop that).
I'll go and check all relevant stuff.
As an after thought I used to be a sparky engineer before I got into graphics you know electric motors generators and stuff
I might be able to help with any problems in these areas.
should the need arise.

what ff says.. and checkthe chain is lubed and not seized up. sounds likely to be the chain. most prob too loose and rubbing or something like a stand/swing arm etc

Cheers fellas checked out the bike and foend the problem, turns out the rear wheel wasn't probably aligned.
Put a ruler across the adjusters one side was 15 mil tother was 18 causing the chain to snake (is that a real term) slightly.
All is ok now.  :bowdown:  :bowdown:  :mad:

Cheers fellas checked out the bike and foend the problem, turns out the rear wheel wasn't probably aligned.
Put a ruler across the adjusters one side was 15 mil tother was 18 causing the chain to snake (is that a real term) slightly.
All is ok now.  :bowdown:  :bowdown:  :mad:

Glad you've cracked it imag

Never trust the marks on the swinging arm, they can be miles out. Measuring the bolt length should be ok as long as both 'arms' are the same length. IIRC some Laverda swinging arms are way different lengths on either side.

My preffered method is to sight the chain from about 10 yards back while someone turns the wheel. You can soon spot if it's out.

FF, thanks! Top tips old chap

I can't use the "birds eye" approach to lining up 'coz the bandy hasn't got a centre stand... But a lump of wood does the trick!

Eliptical chicken strips are a good indicator of wheel misalignment - ie, very close to the tyre edge at the sides ( bike stationary) but larger gap at the top and bottom.  exessive tyre wear on one side.  wheel misalignment is bad news and can shag a chain and sprockets in no time.  everybody laughed when i said any self respecting home workshop should include a plank!

FWIW Eb's dad should lend out one of his eyes as he can spot misalignment at a hundred yards.  Overtook him one day in busy traffic.  Next day received advice from EB to check wheel alignment as his dad reckoned mine was out and guess what?  The trusty plank proved him right!  As a side note the time he spotted me and noticed this fault i was riding the bike home after a service and new C&S fitting at a proper Kawasaki dealer.


FULL DEALER SERVICE HISTORY FROM NEW

TRANSLATION Bike has been improperly serviced on a regular basis throughout it's life.

standard equipment for checking wheel alignment on a bike MOT

2 x planks of wood!

some bikes do have a offset rear wheel tho so dont be fooled!