Heavy steering shake

[JoshuaB]

The other night I was on my way home from work and did a small pull on my Daytona 675, but before getting to around 100kmh, the steering sent itself into an extremely violent shake, even when off throttle. I went down and am now stuck fixing the bike. Does anyone have any ideas with how this couldve happened?. I did notice a steering shake when the front wheel came down from being "unloaded" a couple of times but nothing this bad.
Any help is much appreciated
I also know the Daytona has a steering damper.
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[BusaSteve]

How do you mean a small pull....did you do a wheelie? If so anything could have caused the shake....generally it will be steering bearings being worn or too loose. It also could be extreme tyre wear such as squaring off or even low pressure in the tyre. Your forks may have twisted slightly in the triple trees from past wheelies or one fork could be slightly higher than the other. You need to check out the front end thoroughly before riding the bike again.

[JoshuaB]

How do you mean a small pull....did you do a wheelie? If so anything could have caused the shake....generally it will be steering bearings being worn or too loose. It also could be extreme tyre wear such as squaring off or even low pressure in the tyre. Your forks may have twisted slightly in the triple trees from past wheelies or one fork could be slightly higher than the other. You need to check out the front end thoroughly before riding the bike again.

By pull, I mean acceleration. Don't think the wheel lifted. Pretty sure the tyres are all good, as I picked it up from a dealer a few weeks ago after supposedly having had a full service
I don't think I could've bent the forks myself, any wheelies that I've done on this bike (there haven't been many) have come down quite softly

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[AZAZL]

What Busa said. Also, if you are not very heavy can influence it.

When it is happening, get your weight forward by quickly leaning over the tank. Might help.

Shutting off the throttle can make it worse.

[BusaSteve]

Right... the steering bearing is one of the checks you need to do...it is important to allow for any damage done due to the off re the forks being out of alignment. If they appear to be straight and undamaged it is fairly simple to make sure they are not twisted.

Loosen the triple tree clamp bolts slightly...top and bottom then bounce the bike up and down on the front suspension a few times this should get any twist out...if there is any.

Steering bearings are easy to check. Raise the front clear of the ground...a block of wood under the collector box can be used...make sure it isnt an aftermarket exhaust as most are too thin to support the bike. If the latter is true then a front stand will have to be sourced. The steering should move full lock side to side with a gentle push...any more or roughness indicates bearings that are either dry or fucked...although if dry they will almost certainly be fucked too.

Next check for any forward or backward movement at the wheel being transmitted by the forks...there should be zero. If there is it may mean the bearings need adjustment. Not sure on your bike but most use a 'C' nut under a cover to apply preload to the bearing, specs will be needed.

Whilst there the wheel bearings can be checked in a similar fashion...any movement at the wheel, you will feel the difference, could indicate worn wheel bearings...side to side and up and down. Check the brakes are not binding and the discs are not warped. be sure both sides are free...a single side binding may cause a head shake.

Cant think of anything else other than tyre wear or wheel damage...such as a dent or maybe even a badly mounted tyre...check the wheel sits in the centre of the forks...and if fitted abs is working.

What did the service include and who did it....maybe they fucked up...proving it will be an uphill battle...esp since you ended up dropping the bike

Good luck

[JoshuaB]

What Busa said. Also, if you are not very heavy can influence it.

When it is happening, get your weight forward by quickly leaning over the tank. Might help.

Shutting off the throttle can make it worse.

Would a better quality steering damper help? I only weigh 55kg so using my weight Doesnt have a large effect

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[Mr Bean]

The stock steering damper on a 675 is non adjustable and inadequate in preventing a serious tank slapper. Something aftermarket like a GPR or Hyperpro will do the job properly.

Technique: When you encounter a tank slapper for the first time the normal instinct for someone inexperienced is to back off the throttle. Don't do that. You need to stay on it and not fight the head shake with your arms or body. Basically, let the bike shake and wobble and you go along for the ride. Most of the time it will settle itself.
Even with an aftermarket adjustable steering damper you still need to use technique. Don't make the mistake of winding the damper all the way up thinking that will prevent it happening again. You don't want to take away from rider feel or input.

[JoshuaB]

Right... the stearing bearing is one of thew checks you need to do...it is important to allow for any damage done due to the off re the forks being out of alignment. If they appear to be straight and undamaged it is fairly simple to make sure they are not twisted.

Loosen the triple tree clamp bolts slightly...top and bottom then bounce the bike up and down on the front suspension a few times this should get any twist out...if there is any.

Steering bearings are easy to check. Raise the front clear of the ground...a block of wood under the collector box can be used...make sure it isnt an aftermarket exhaust as most are too thin to support the bike. If the latter is true then a front stand will have to be sourced. The steering should move full lock side to side with a gentle push...any more or roughness indicats bearings that are either dry or fucked...although if dry they will almost certainly be fucked too.

Next check for any forward or backward movement at the wheel being transmitted by the forks...there should be zero. If there is it may mean the bearings need adjustment. Not sure on your bike but most use a 'C' nut under a cover to apply preload to the bearing, specs will be needed.

Whilst there the wheel bearings can be checked in a similar fashion...any movement at the wheel, you will feel the difference, could indicate worn wheel bearings...side to side and up and down. Check the brakes are not binding and the discs are not warped. be sure both sides are free...a single side binding may cause a head shake.

Cant think of anything else other than tyre wear or wheel damage...such as a dent or maybe even a badly mounted tyre...check the wheel sits in the centre of the forks...and if fitted abs is working.

Good luck

Awesome thanks. I'm getting a service manual this week so will confirm all details against that as I check

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[Benny D]

front wheel lifted off.
went down out of alignment.
backed off throttle as it started to shake.
full blown talk slapper ensued.
down he went.

[Ryanoceros]

what year Daytona is it ?

[JoshuaB]

front wheel lifted off.
went down out of alignment.
backed off throttle as it started to shake.
full blown talk slapper ensued.
down he went.

What do you mean by "went down out of alignment"?

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[JoshuaB]

what year Daytona is it ?

2008 Daytona without abs

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[Benny D]

What do you mean by "went down out of alignment"?

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front wheel was pointing either left or right instead of straight. even just a bit would be enough for a bit of a shake. add to that cut the throttle will amplify those shakes.

[BusaSteve]

I was under the impression he didnt lift the wheel at all and this is something that is happening while under heavy acceleration and the front is unloaded so to speak. I assume a Daytona has pre load and rebound settings on the front....perhaps the rebound is set too high (slow) and when the front becomes light under acceleration it stays that way too long?

[JoshuaB]

I was under the impression he didnt lift the wheel at all and this is something that is happening while under heavy acceleration and the front is unloaded so to speak. I assume a Daytona has pre load and rebound settings on the front....perhaps the rebound is set too high (slow) and when the front becomes light under acceleration it stays that way too long?

I thought the wheel didn't lift, but I don't exactly remember a tonne from the crash anyway. So could have and I don't remember

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