[Zookie]

Please go easy on me, I'm a total beginner.
I KNOW hands shouldn't come off the handlebars but if I take them off then the steering and front tire start shaking and jerking violently side to side after about 2 seconds. Not always. Is it just the road not being smooth or is there something I need to get checked?
Thank you

 

[bcalan]

This is the first stage of a "tank slapper" where the bars go so violently from side to side you lose all control and crash. Can be fatal. Watch some Youtube vids. Some owners report this occurs when they have a rear trunk loaded. Can be caused also by worn wheel bearings front or rear, worn swingarm bearings or worn/loose steering head bearings. How are your tires? Are they mismatched by maker or radial and bias mixed? Lotta stuff to look at.....

 

[Zookie]

This is the first stage of a "tank slapper" where the bars go so violently from side to side you lose all control and crash. Can be fatal. Watch some Youtube vids. Some owners report this occurs when they have a rear trunk loaded. Can be caused also by worn wheel bearings front or rear, worn swingarm bearings or worn/loose steering head bearings. How are your tires? Are they mismatched by maker or radial and bias mixed? Lotta stuff to look at.....

Thanks for the reply.Its a brand new bike I've only done 550 miles on it. Tyres are new and OEM.

 

[maccecht]

Adjust your rear shocks to a higher setting and stop taking your hands off the bars you may have a mishap if you hit a bump or pothole and as noted above get a tank slapper which can rarely be saved it's normally tarmac interface time when it happens

 

[mike1nw]

Have dealer check steering bearings and wheel bearings. I bought a 2005 Concours (new) and within a few hundred miles, the front end was making horrible knocking sounds, steering was loose.... dealer tightened the triple tree, fixed.

You should be able to momentarily take hands off the bars, the bike SHOULD NOT weave, shake, wobble, etc.

 

[mikeyMarine]

Yup , (if it occurs on multiple roads) new bike take it back to stealership, tell them when hands are LIGHTLY placed on grips, (which is the way it should be tested) after a second or two it starts shaking.
A real tank slapper will kill, I kinda don't think yours is a normal tank slapper as they will occur with hands on as well and you will feel it in your hands.
My stealership sent me out on unsafe bikes twice. Trust no one but Ledude and Michbergsma (and Merry Mary at the Kitty Kat Klub)

 

[Dave_J]

What you are seeing IS a Tank Slapper but it is contained by your hands adding stabilization. You need to have it checked. It is an easy fix. But you need the dealer to fix it.
My 2008 was real bad. I could not take ether had off the bar before I could feel it slowly start.

It requires taking the handel bar covers off, then the front top box off. Then you loosen up the bottom two bolts on BOTH fork tubes. Now the top lock nut on the steering stem of the triple tree must be loosened. Then using that funny shaped tool in your tool kit you turn the notched nut tighter till you get the set amount of 'Pre Load' set in the service manual. Then lock the steering stem nut down, tighten the two bolts on the fork tubes and put the top box and handle bar covers back on. 1 Hours work.
You need:
1. 12mm wrench/socket.
2. Funny tool (Spanner) See pic
3. 19mm wrench for Stem nut.
4. A Fishing weight scale to use to pull the handle bar's pre load.

 

[s-steel]

Thanks for the reply.Its a brand new bike I've only done 550 miles on it. Tyres are new and OEM.

welcome
new to you, but a used bike? or a new from dealer 2020 model? only 500 miles on the odometer?

if you have a rear storage box(what model brand?), most likely its that. if its a new scooter. if you have a quick release tray, you can take out the box, take it for a spin and see if it does the same.

 

[Dave_J]

OK, quick test. It may or may not show the trouble but on my 2008 650 it did.

Put bike on center stand. Put a cars scissor jack under the bike's engine up front and lift the front wheel off the ground/earth. Then strattle the bike's hump and push forward on the handle bars, then pull back. You should not have any play front to back.

 

[Zookie]

welcome
new to you, but a used bike? or a new from dealer 2020 model? only 500 miles on the odometer?

if you have a rear storage box(what model brand?), most likely its that. if its a new scooter. if you have a quick release tray, you can take out the box, take it for a spin and see if it does the same.

Brand new bike 2020 400. I did just put a storage box on from new a Shad SH58. If it is the top box am I safe? Thank you

 

[s-steel]

remove it. its very easy. you have a 2nd red button under the lock, press and hold the button, lift and pull towards you. slip the case off. take it for a ride and see how it goes.

to slip it back in, no need to press the button. the back has 2 tabs...align it to the back tray and see it gets into their slots then snap the front down (where the lock is) and thats it. shake it to see thats its locked in place.

let us know how it goes.

every bike will shake if they have a top box. put your hands lightly around the grips. if it dances right away violently, then you have a problem, but every bike will shake if you release your hands from it.
very easy to take the box off, take it for a ride and keep hands very loose around grips to let them find their way.

when I did deliveries there was 1 specific scooter that would shake like crazy if you even held it with 1 hand. I think ti was in an accident prior and steering or struts got bent. but on my hd200 it will shake as well if I let go.

 

[Dave_J]

Brand new bike 2020 400. I did just put a storage box on from new a Shad SH58. If it is the top box am I safe? Thank you

Some bikes will have Head Shake Or Tank Slapper due to an over sized or bad aerodynamic Top box but MOST Burgmans do not.

The causes of head shake are mentioned in posts above. Some are bad Tires. Bad wheel bearings. Bad load distrubution. Bad or not adjusted steering bearings.

If the the steering bearings need adjusting, the rear top box may compound the issue A LOT.

 

[Zookie]

Thank you so much for all of the responses everyone, I really appreciate it. Going to try without topbox as S Steel said and get the stealership to check bearings etc. Thank you

 

[maccecht]

Having a top box on changes the aerodynamics dramatically as the air passes over the screen and rider it creates a vortex behind your back you probably noticed this when you first fitted the top case. This vortex pushes down on the top case making the front end of the bike light. To compensate increase the preload on the rear shock.

 

[Zookie]

Having a top box on changes the aerodynamics dramatically as the air passes over the screen and rider it creates a vortex behind your back you probably noticed this when you first fitted the top case. This vortex pushes down on the top case making the front end of the bike light. To compensate increase the preload on the rear shock.

Do you know if a taller or lower screen would help this please? I would prefer a lower aesthetically but do you reckon either would help? Thank you

 

[maccecht]

Not really you still have a vortex adjust your rear shock and report back

 

[Zookie]

Not really you still have a vortex adjust your rear shock and report back

Thanks will do, also lets assume it is the top box for a moment- will it get worse/is this shaking enough to make me crash? Thanks

 

[Uncle Fester]

Most of my scooters and motorcycles have had steering wheel shakes at certain speeds while decelerating with the hands off the bars. The worst was my 2012 DL650 when decelerating from 100 mph went into a full blown tank slapper. When I had my Honda ST1100 the forum said some tire brands were more prone to head shake and also the stock steering head bearings being replaced with tapered bearings would help.

 

[maccecht]

When new most bikes have the suspension set low for lightweight riders most Japanese will be 8 stone wet. By adding the top box out over the back wheel you changed the balance so with soft set suspension you will get a head shake. It's a new bike so you can rule out bearings tyres etc as they go go through a PDI before sale. It's not impossible of course but unlikely. As for predicting will it get worse or will you crash if I could answer that I would be a lottery winner.

 

[AlanT]

Sounds like a similar problem I had (as did many others) on my Forza wit the stock tyres, fitting Pirelli solved it (or did they just do a good balance job).
My Burg 400 has shown no such characteristics. So hope it is as simple as that.