Traction Control

[andybarsblade]

Yeah that would be my guess, i've had shakes on the road even with my ohlins damper when ive been pulling back on the bars but when i push forward more with my legs and relax my grip a little i have no problems.

 

[Godzilla]

Thats what I would guess as well.

 

[Liam]

Hi,
I'm the rider in the video. I've had a read through the thread and i seen a lot of you are saying that i was holding on too tight, I can tell you this was not the case had i been holing on too tight i would have been off the bike.
I've done a lot of Trackdays at Knockhill and on previous bikes its not been a problem for me.
The suspension has been professionally set-up and as a one of you said about the pre-load being out a fair bit yes I am a light rider.

 

[phil]

The suspension has been professionally set-up and as a one of you said about the pre-load being out a fair bit yes I am a light rider.

That was me, so what do you think was the cause and has it happened since? maybe on the same day?

Phil

 

[Liam]

The cause was the front wheel coming down (not my choice) gingerly on an uneven surface, its started to wobble and because the DTC started to intervene I couldn't power out of it, The slapper got worse and so the DTC went full retard and the bike started to decelerate throwing all the weight forward, that's why it got so severe.
I got some very slight head shake again during the session on the same part of the track, DTC was then turned off.
I'm not at all amused by the fact that i spent over £14k on a brand spanking new bike and its come with a weak as cats piss steering damper, especially as the bike is clearly track focused. Lap Timer, Race DTC etc

 

[Godzilla]

What do you mean by 'uneven surface'.

I find it difficult to believe the bike caused this, as the DTC has put lots of wheelies down for me, but that has never happened.
Also as soon as the front wheel lands the power comes back in and the front lifts again, causing a sort of pogoing effect.
This really does puzzle me.

 

[andybarsblade]

The cause was the front wheel coming down (not my choice) gingerly on an uneven surface. You seem to be very certain about it but the fact is your guessing to this being the cause just like we are.

 

[Liam]

What do you mean by 'uneven surface'.

I find it difficult to believe the bike caused this, as the DTC has put lots of wheelies down for me, but that has never happened.
Also as soon as the front wheel lands the power comes back in and the front lifts again, causing a sort of pogoing effect.
This really does puzzle me.

When it started the head shake the wheels were no longer spinning at the same speed, That's when DTC steps in. If DTC is active then its retarding the ignition which means I couldn't power out of it. I really don't know why some of you are finding that so hard to understand.

 

[Godzilla]

What do you mean by 'uneven surface'.

I find it difficult to believe the bike caused this, as the DTC has put lots of wheelies down for me, but that has never happened.
Also as soon as the front wheel lands the power comes back in and the front lifts again, causing a sort of pogoing effect.
This really does puzzle me.

When it started the head shake the wheels were no longer spinning at the same speed, That's when DTC steps in. If DTC is active then its retarding the ignition which means I couldn't power out of it. I really don't know why some of you are finding that so hard to understand.

I know what DTC is and how it works.

Why I don't understand is that when it puts the front wheel down on my bike it doesn not have that effect. the wheels spinning at different speeds will not start a headshake imho.

 

[Liam]

I know what DTC is and how it works.

Why I don't understand is that when it puts the front wheel down on my bike it doesn not have that effect. the wheels spinning at different speeds will not start a headshake imho.

Now you're putting words in my mouth.
Head shake started, DTC kicked in and i couldn't take action to get out of that situation because DTC thought it knew better.
Try and take the BMW blinkers off and understand that this bike has faults.

 

[Godzilla]

I do not believe this bike is perfect, far from it.

Maybe you should also take the blinkers off and accept that maybe it was't all the bikes fault.

 

[seb#143]

It was 100% the bikes fault in my opinion. How do I know this? I have tried every geometry and electronic setup on the BMW flat out no holes barred on track. Running the S1000RR on track with that geometry (with the forks so far through the yokes) causes massive tank slappers, general instability, the bike will enter a corner pretty well and turn tight off the throttle... once the throttle is picked up the bike WILL run wide.

Flushing the forks or even setting to 1 ring (approx 7mm including fork cap) through the yokes will increase stability massively, reduce the twitchy front end, improve rear grip and let the bike finish the corner.

Also the BMW DTC does NOT retard ignition. It manipulates throttle opening (press gumph states reduces torque) based on rear wheel slip - my data logging shows this when I run the traction (which is hardly ever). This is why it can 'pogo' out of corners as the throttle is electronically stepped when DTC kicks in. In race mode the traction and anti wheelie is far too intrusive for dry track use. In slick mode the traction is bearable on track and is even useful in the wet.

So... well held, sir!! Certainly got hairy there. Definitely change the geometry - it doesn't take 2 minutes to do. And if you have some spare cash a GPR steering damper will improve stability massively. Hope that helps.

 

[Liam]

It was 100% the bikes fault in my opinion. How do I know this? I have tried every geometry and electronic setup on the BMW flat out no holes barred on track. Running the S1000RR on track with that geometry (with the forks so far through the yokes) causes massive tank slappers, general instability, the bike will enter a corner pretty well and turn tight off the throttle... once the throttle is picked up the bike WILL run wide.

Flushing the forks or even setting to 1 ring (approx 7mm including fork cap) through the yokes will increase stability massively, reduce the twitchy front end, improve rear grip and let the bike finish the corner.

Also the BMW DTC does NOT retard ignition. It manipulates throttle opening (press gumph states reduces torque) based on rear wheel slip - my data logging shows this when I run the traction (which is hardly ever). This is why it can 'pogo' out of corners as the throttle is electronically stepped when DTC kicks in. In race mode the traction and anti wheelie is far too intrusive for dry track use. In slick mode the traction is bearable on track and is even useful in the wet.

So... well held, sir!! Certainly got hairy there. Definitely change the geometry - it doesn't take 2 minutes to do. And if you have some spare cash a GPR steering damper will improve stability massively. Hope that helps.

Thanks for that informative post. As part of the suspension setup I had done they raised the forks by one ring. I will drop the forks by a few rings at the weekend and see how it goes.
As for a damper I was thinking of getting an Ohlins as it looks like a straight swap from the stock item.

 

[phil]

Running the S1000RR on track with that geometry (with the forks so far through the yokes) causes massive tank slappers, general instability

Flushing the forks or even setting to 1 ring (approx 7mm including fork cap) through the yokes will increase stability massively, reduce the twitchy front end,

So very correct Seb Liam, best get the tools out mate.