wobbly bars... top box?

[ocatoro]

Hey dudes, been using bike for work... I have a habit of slowing to lights etc with no hands on. Bars still.

Fitted top box yesterday and if take hands off the bars wobble like hell.

Why would a top box do that? Only had a rucksack with laptop and some dinner in it.
____________________
CBT - 17/09/12 * Theory - 23/10/12 * Mod1 - 05/03/13 * Mod2 - 25/03/13 * BOSH!
Current - None but shed project H100 (first bike )
Past - ER5, '93 ZZR600, '92 CB400 SF, ZZR600 (again), yellow Monster 620, Blackbird - black Monster 620ie - '96 ZZR600

[notbike]

Not sure stopping with no hands on the bike is a good place to start in the first place let alone with some extra weight on the rear.

Typically when you have extra weight on the rear it'll make your steering lighter, so wobbling at low speed and deceleration is expected.

Not sure if it's something to do with the shocks cause I'm not too mechanically minded yet haha but might wanna see if the extra weight is compressing the rear shocks a lot more than it should, might want to stiffen the shocks.

Edit: It might not be that it's extra weight, the weight inside the top box could be more to the left or to the right throwing the balance off a little.

[Ariel Badger]

[ajag]

What are you doing with your hands while you are slowing down that you cannot hold on to the bars?
____________________
Street Triple

[Robby]

Your bike has been carefully designed to handle as it did, with the centre of mass in the middle of the bike and low down.

You then go and put a weight as far from the centre of mass as possible. The front end is now light, handling will suffer.

Keep your hands on the bars.

[Rogerborg]

[pinkyfloyd]

This.

[ws4936]

[Copycat73]

loose stearin head bearings.
the weight on the back of the bike exacerbates , but is not the cause.
____________________
Whatever I post I have no citation and no intention of providing one..
caveat emptor

[Snorty]

[MarJay]

Notched steering head bearings don't cause wobbles. They cause the steering to be notchy or heavy, but not a random wobble.
____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F; Cheap project: CBR900RR FireBlade
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[Copycat73]

the wobble is predictable.. on the over run .. slowing down often with some load on back wheel..
it has to be said that wheel bearings should also be checked.. if only to rule them out.
____________________
Whatever I post I have no citation and no intention of providing one..
caveat emptor

[ocatoro]

Ok fair I probably walked into that. I don't mean quite as triumphantly cnut as it sounds. I just take that opportunity to sit up and have a stretch under engine braking quite often.

There was not even the slightest hint of this until now. Box is off... Will test again shortly.

Steering is free and smooth. But will check bearings to see if any worn at weekend.
____________________
CBT - 17/09/12 * Theory - 23/10/12 * Mod1 - 05/03/13 * Mod2 - 25/03/13 * BOSH!
Current - None but shed project H100 (first bike )
Past - ER5, '93 ZZR600, '92 CB400 SF, ZZR600 (again), yellow Monster 620, Blackbird - black Monster 620ie - '96 ZZR600

[sidewinder]

Divvy used to do this.cured by putting a few psi more in the tyres

[ocatoro]

So it stopped again without top box. Grrr

So smooth you could rest a coffee on the bars
____________________
CBT - 17/09/12 * Theory - 23/10/12 * Mod1 - 05/03/13 * Mod2 - 25/03/13 * BOSH!
Current - None but shed project H100 (first bike )
Past - ER5, '93 ZZR600, '92 CB400 SF, ZZR600 (again), yellow Monster 620, Blackbird - black Monster 620ie - '96 ZZR600

[trevor saxe-coburg-gotha]

[ocatoro]

like i said man, it's by no means every time. just a sit up and stretch whilst engine braking.
____________________
CBT - 17/09/12 * Theory - 23/10/12 * Mod1 - 05/03/13 * Mod2 - 25/03/13 * BOSH!
Current - None but shed project H100 (first bike )
Past - ER5, '93 ZZR600, '92 CB400 SF, ZZR600 (again), yellow Monster 620, Blackbird - black Monster 620ie - '96 ZZR600

[evoboy]