Vibration at 80-90Ks in 5th gear

[youngSTer]

Hi There, I have just had new tyres fitted and at 80 to 90ks in 5th gear there is a vibration like riding over a cattle grid. It is not continuous, runs for about 2 seconds or so then their is nothing for another 2 seconds. The people who fitted the tyres have told me that it is a harmonic balance vibration between the new tyres and engine revs at that speed because Metzler Z6 have more steel in them than other brands.
Was not here with the old tyres.
Suggestions please.

[Biggles]

Ride at 100 kph.

[alans1100]

I've had Z6 tyres before and nothing like what you described as happened.

[STeveo]

Take the bike back to the people who fitted the tyres and ask them to deflate them and turn 90 deg and reinflate and balance them again. Fixed a similar problem I had years ago.

 

[Skip]

Failing that, request a new tyre. Have never heard of that.

[saaz]

Sounds doubtful to me. I have used the Z6s before and no problems.  That speed is one of the most likely to show up a tyre not seated properly or way out of balance.

[terrydj]

Take the bike back and get someone else to fit the tyres. Better still get someone from the shop to ride it

[scarp]

Ride at 100 kph.

[rendog]

Dude,
A vibration at that road speed and engine revs should be constant,
not this come and go every two seconds as you describe.

Doctor says:
a) ride at same speed in different gear and still vibrates = rims and suspensions issue
b) ride at same engine revs in different gear and still vibrates = engine issue
c) specific combination of engine revs and road speed it's a drive line issue, which includes drive shaft, final drive, axles, bearings etc.

My initial thoughts are it is a drive line issue.
Coming so close to having new tyres fitted is obviously suspicious though.
I would check, in this order:
# Everything wheel fitter's touched is tight
# Spacers in the correct position or missing - are the wheels aligned correctly with no lateral movement?
(though I don't know if it's physically possible to put it all together wrong)
# Even go so far as to check that there is oil in the final drive and correct spline alignment of hub and rear rim.
# Check all wheel bearings.
# Remove any balance weights on the rims.
# Rotate the tyres on the rims (as previously suggested).

Hope that helps & keep us informed 

[scarp]

That's what I like about this site informative information that's a great help

[Dennisgw]

Hi There, I have just had new tyres fitted and at 80 to 90ks in 5th gear there is a vibration like riding over a cattle grid. It is not continuous, runs for about 2 seconds or so then their is nothing for another 2 seconds. The people who fitted the tyres have told me that it is a harmonic balance vibration between the new tyres and engine revs at that speed because Metzler Z6 have more steel in them than other brands.
Was not here with the old tyres.
Suggestions please.

I can quote the same situation as you describe so am interested if you have come up with a solution. The suggestion I heard was to give the tyres 1000km to settle in because of their construction and aggressive nature.

What I also know is that when running at 100kph in 5th, the vibration is as described. Change back to 4th and maintain road speed and the vibration seems to become constant.

[Dennisgw]

Sounds doubtful to me. I have used the Z6s before and no problems.  That speed is one of the most likely to show up a tyre not seated properly or way out of balance.

The problem as described is certainly more of a harmonic issue that balance. Balance will be consistent within a limited speed range so I would discount that as a cause.

[youngSTer]

Hi All, Thank you all for your input on this issue that I have been having.
I took the bike back and rotated the rear tyre 180 degrees and this reduced the vibration quite significantly and now that I have nearly 400ks up on the tyres the vibration is going away almost to the point where it is not noticeable.

[Dennisgw]

Hi All, Thank you all for your input on this issue that I have been having.
I took the bike back and rotated the rear tyre 180 degrees and this reduced the vibration quite significantly and now that I have nearly 400ks up on the tyres the vibration is going away almost to the point where it is not noticeable.

Sounds like it fits in with what I was told this morning.
Thank You for the feedback.

[Lonerider1]

I have read that the new z8's are much better. The yanks are raving over them.

[youngSTer]

Believe it or not I just checked and they did fit z8's

[Dennisgw]

Believe it or not I just checked and they did fit z8's

Damn, Thought I would check mine after this post. ...... Z6 on front and Z8 on the rear. Maybe the vibration is a Z8 problem and not Z6 after all!

[Dennisgw]

I have read that the new z8's are much better. The yanks are raving over them.

I took mine over Mt Mee last Friday afternoon. Sure feels like a more sure footed and confident bike that it did with the Bridgestones. To coin a phrase, "... felt like it was on rails ...".

[Dennisgw]

Hi All, Thank you all for your input on this issue that I have been having.
I took the bike back and rotated the rear tyre 180 degrees and this reduced the vibration quite significantly and now that I have nearly 400ks up on the tyres the vibration is going away almost to the point where it is not noticeable.

Hey Young One,

How are your tyres performing? I imagine that you will ahve a few ksm on them by now.

Regards

Dennis

[Biggles]

"Young One" will be back from Tassie soon.  I got back this afternoon after doing 5428 km since I left home.
No doubt about those Tassie roads, not many straight bits!
Anyhoo- to the topic...  while he had some spare time in Hobart, Tony visited the Honda agent.  His vibration problem was simply solved with a dynamic wheel balance.  Seems a static balance just wasn't good enough, or done well enough here in Brissie.
No doubt he'll tell the full story when he gets back.

[Dennisgw]

Thanks Biggles.
Dynamic balance had crossed my mind but then I discounted it given the nature of the wheel mounting and strut.
I shall go and give it a try.
Cheers
Dennis

[youngSTer]

Hi All, Vibration is still there even after 5530 km's to Tassie and back.
Will be contacting the tyre guy today.
Will keep you posted.
 

[Dennisgw]

Does anyone around Brisbane have a spare rear wheel and tyre for a 1300 I can borrow for an hour or so?
Just need to separate the Metzeler from the bike for a short time to prove, or disprove, the point.

On another note, I took the bike back to the tyre fitters this week only to find that the driven flange bearings had collapsed, after 31000K.

[Dennisgw]

Well, am sure I have fixed my problem!!!

Replaced the rear tyre with a BT-023 a few weeks ago and left the Z6 on the front and it was a huge improvement.
What I did start to notice since then though was that the bike did not feel as secure on the road at speed under some conditions so today the front Z6 has been removed and also replaced with a BT-023.

So endeth any relationship with Metzeler tyres. I would suggest people think twice before fitting Metzeler Roadtecs and definately don't buy in Moss St Slacks Creek!!!!