Developing drivetrain vibration?

[Taipan]

Hi All

My bike seems to have developed a vibration which comes through the bike. This is different to the sort of buzziness that gives numb fingers. This is more of a shuddering. Bike is quite smooth at say 80 mph, but if you open the throttle wide at low revs to use the torque you really feel it coming through the chassis. I haven't looked or checked anything other than chain tension which seems okay. I'm not sure it’s linked but this does seem to coincide with the fitting of my ZX10 shock? Any ideas on what the cause could be?

Many thanks

For those having difficulty reading the above...

<Quote>
Hi All

My bike seems to have developed a vibration which comes through the bike. This is different to the sort of buzziness that gives numb fingers. This is more of a shuddering. Bike is quite smooth at say 80 mph, but if you open the throttle wide at low revs to use the torque you really feel it coming through the chassis. I haven't looked or checked anything other than chain tension which seems okay. I'm not sure it’s linked but this does seem to coincide with the fitting of my ZX10 shock? Any ideas on what the cause could be?

Many thanks

</Quote>

You may be getting more vibrations through the chassis as a result of the shock change, it may have differant harmonic frequencies. But i doubt it would make such a noticable differance!

Check al the bolts are of the correct torque; perhaps go around the frame and check the bolts that hold the engine to the frame - loosen, and re-torque. Are you holding on a bit tighter because you're cold?

[Mr Speirs]

Originally Posted by LankyIanB

For those having difficulty reading the above...

<Quote>
Hi All

My bike seems to have developed a vibration which comes through the bike. This is different to the sort of buzziness that gives numb fingers. This is more of a shuddering. Bike is quite smooth at say 80 mph, but if you open the throttle wide at low revs to use the torque you really feel it coming through the chassis. I haven't looked or checked anything other than chain tension which seems okay. I'm not sure it’s linked but this does seem to coincide with the fitting of my ZX10 shock? Any ideas on what the cause could be?

Many thanks

</Quote>

Whats this all about? I can read it fine thanks

Taipan I don't think its related to your shock either but maybe its worth just having a check round to make sure everythng is installed correctly n still tight.

[Taipan]

Originally Posted by Alpinestarhero

You may be getting more vibrations through the chassis as a result of the shock change, it may have differant harmonic frequencies. But i doubt it would make such a noticable differance!

Check al the bolts are of the correct torque; perhaps go around the frame and check the bolts that hold the engine to the frame - loosen, and re-torque. Are you holding on a bit tighter because you're cold?

Good call as the previous owner did fit another engine to the bike. It is like that sort of shuddering too. best I can alike it to is if you've ever had a car thats snapped an exhaust bracket and the exhaust is now rubbing on the car body.

Originally Posted by Mr Speirs

Whats this all about? I can read it fine thanks

Taipan I don't think its related to your shock either but maybe its worth just having a check round to make sure everythng is installed correctly n still tight.

I'm normally pretty thorough when doing something, but of course I could have got something wrong during reassembly. I'm certainly not above making mistakes! I dont like coincidencies though and it does seem like one when this develops just after I've worked on the chassis parts. Might well be the gearbox lunching on itself though! . For me the golden rule is always go back to the last place you worked. So this weekend I'll get it up in the air and have a look from underneath etc.

i'd imagine the vibration is from somewhere loose so either one bolt from the shock or the chain itself being loose.

[yorkie_chris]

Chain slap by the sound of it, if you changed shock then you have changed chain tension at given point in wheel force.

Open throttle at high rpm, problem solved.

Originally Posted by yorkie_chris

Open throttle at high rpm, problem solved.

less Problem Solved and more Avoiding the Issue? Also, if it is causing a low-frequency vibration through the bike at lower RPM, then at higher RPM, higher frequency vibrations may occur which didn't before, causing something to loosen itself

perhaps

[Biker Biggles]

If it does coincide with you fitting a different shock I would take a hard look at the bits you have disturbed.Is everything done up tight,and does the new shock clear the swingarm and battery box fully?I saw a recent thread where a ZX shock fouled the swingarm on a curvy which had non standard dogbones.Just a thought.

[yorkie_chris]

Originally Posted by Alpinestarhero

less Problem Solved and more Avoiding the Issue? Also, if it is causing a low-frequency vibration through the bike at lower RPM, then at higher RPM, higher frequency vibrations may occur which didn't before, causing something to loosen itself

perhaps

Is it same sort of slap you get when you open throttle at really low rpm like 1500?