What causes a speed wobble (high speed weave)

[flipper]

That's exactly what I do. I find that it is the accuracy of the veneer that's stops the wobble

your bike is laminated?

 

[flydnb]

He loves a bit of wood to play with.

 

[Triple Trouble]

your bike is laminated?

Of course..! It's the way ahead lol

 

[Triple Trouble]

He loves a bit of wood to play with.

The MT always gives me the wood lol.

 

[stevecbr]

I also had speed wobbles that started about 170Kph but now it's fixed.

There is a design concern with the chain adjuster which is parallax error as the swing arm mark sits 10mm above the adjusting block. If your not square with the marks then you can end up with a substantial error. Before I made my first adjustment using the vernier, I found that I had a 1.5mm difference between the two adjustment blocks

I now use a vernier calliper to accurately measure the distance between the machined locknut web and the adjusting block. I then firmly tighten the axel nut and recheck the adjusting block measurements on both sides, check chain tension again, then torque the axle nut using a torque wrench set at 150Nm to do the job correctly.

This seems to have fixed my problem, best of luck with yours.

Are you sure that works? I had mine laser aligned to try and cure it, I have just rechecked it with a straight edge and its totally straight. However, using vernier calipers with method you describe, there is a difference between both sides of nearly 2mm (I am however using the standard Yamaha soft alloy adjusters, which have deformed slightly). I think the straight edge or laser alignment is the only correct way to measure

 

[Chris West]

This may or may not be of any assistance but mine had awful weave (I mentioned it somewhere on here)
Seemed to be back pack related!?!
But it has now simply disappeared ?
Whether I use the back pack or not, I haven't changed anything, it just not there.
Unless it's shifted much further into triple digits.

 

[mudd]

I managed to do some track work with mine since my last attempt at alignment and have found that the wobble that started at about 180Kph now starts at 225Kph and is not as severe as before. I have just rechecked my alignment and have made a 0.3mm change to the setting and will advise if this has improved things but doubt that the alignment should be that critical.

 

[Kinjane]

Having come across the recent veneer thread updates I decided to check the length of my exposed adjusting bolts with a vernier today.
After allowing for the shims which hold the rear spindle firmly in one place, the left hand adjuster needed to be 1.25mm further back than the right hand side one to leave my wheels in alignment.

 

[bingowatts]

Love the sheepskin rug on the seat !

 

[Kinjane]

Love the sheepskin rug on the seat !

Adds comfort and reduces the chances of Urethral stricture - that's a win win as far as I'm concerned

 

[Twozup]

Guys I know this is prob one of a hundred causes/ solutions but here's what's caused mine-
I had the back wheel off back in summer and took it to get new tyre and balanced off the bike to save money
I put the back wheel on myself- horsed up by hand WITHOUT checking proper torque as I was in a rush to get out asap- lined everything up and at anything over the magic number (on a closed runway etc) the bugger was all over the place as the front went light. Squeaky Bum Time

I've been commuting on it a lot this past month or three and gave it a strip down and wash at wknd- full monty back tyre off into the swingarm scrub!

I put the wheel back on and WITH A TORQUE WRENCH tightened up the wheel spindle nut to the proper 146 (or 150!) nM and hey presto

NO MORE WOBBLE on a flat out run (again on a closed runway.....)

Note to self-Don't fanny about do it properly EVERY time.

As I say this is only what happened to me but might be worth a check guys.....



Classic Street Tracker project underway for winter......

 

[Triple Trouble]

146? I thought it was 150 bud?

 

[Twozup]

Not at the back wheel nut mate- straight from the horses mouth- the Technician at the dealer I bought it from - don't imagine 4 Newton metres would make a real noticeable difference at that setting tbh.
I reckon I was a fair bit off (ie well under)

Classic Street Tracker project underway for winter......

 

[Triple Trouble]

Not at the back wheel nut mate- straight from the horses mouth- the Technician at the dealer I bought it from - don't imagine 4 Newton metres would make a real noticeable difference at that setting tbh.
I reckon I was a fair bit off (ie well under)

Classic Street Tracker project underway for winter......

Dude check out the bit I've highlighted here

 

[ToastedBlue]

Dude check out the bit I've highlighted here

View attachment 2446

can't read that but my manual says 108ft/lb which is near enough 146Nm

 

[Triple Trouble]

150Nm

 

[flydnb]

Torquegate .

 

[ToastedBlue]

View attachment 2447

150Nm

the nerdy bit... 1 Nm = 0.73756 ft/lb

fight fight fight

 

[Triple Trouble]

Lol. That info was from taken directly from page 2-19 of the official Yamaha Workshop Manual. Shit I best ring them and tell them their technical guys have got it all wrong lol.

Roger, over and out...

 

[Twozup]

Torquegate .

Haha Blue Touchpaper well and truly lit by Fly de Boi (he with the large stirry spoon!)

If that's what the manual says I'll go with that!

I'll bow to common sense though and say that there won't be a heck of a difference between 146 & 150 in the relative (operative word) sense.

None that I can notice anyways!

And the wheel ain't going to fall off at either of those freakin settings- that's flipping TICHT!
(that's a word just for you TT mate ;-))

Anyway- the moral of the story is that MY speed wobble, as per the OP is now sorted. Phew [emoji41]

Peace Out as they say in the hood. Innit.




Classic Street Tracker project underway for winter......