Motorrad Weekend Knockhill

[Loupe]

Both days Paul... booked n paid

Cool, see you there dude!

 

[alex]

Ah ok, looks nothing like the top pic but not as smooth as the lower pic. I take it the lower pic is your tyre?

No chap - it's the pic from the website quoted above the first picture.

 

[Loupe]

No chap - it's the pic from the website quoted above the first picture.

Ok ta, didn't check the link as I was at work. Will look later.

 

[fast_ryan]

Lowside

A lowside generally happens when you lose front end grip with the bike already leant over and it simply slides away beneath you. There are a few common causes and most can be attributed to rider error. The first cause is overuse of the front brake with the bike leant over and this normally occurs when you trail the brake into the corner and to the apex before you get back on the throttle to balance the bike. The second cause is too much lean angle for the conditions and this doesn't necessarily mean wet or dry, but all also the type of track surface. The third cause is carrying too much lean angle on a closed throttle thus putting excessive weight on the front tyre. This is perhaps the most common cause of crash on trackdays along with cold tyres. Fourth, running off the edge tyre with too much lean. This is rare but can still happen, but it's normally the rear tyre that breaks away first but the bike will still go down in the form of a lowside. Finally, lifting the front tyre off the ground mid-corner can also occur if the bike decks out. This can typically occur in slow speed corners, or hairpins, if you do not have sufficient ground clearance.

Tyre release agents are a thing of the past and you can quite happily scrub in a new set of Pirelli Supercorsas, Metzeler Racetec RRs, or any other race/track orientated tyre for that matter, in less than a lap. As for slicks you may struggle more as they require greater temperature and load generation to work properly. Until you get them up to operating temperature once off the warmers they can feel particularly vague and offer very little in terms of feedback.

I've experienced pretty much all of the lowsides listed above when racing and the main thing is to analyse what went wrong, learn from it and move on.

 

[fast_ryan]

Pirelli Supercorsa SP

This is the type of tyre wear that you want to see from a rear Pirelli Supercorsa SP with well set up suspension.

 

[Loupe]

Thanks for the very interesting and informative post Ryan, I really appreciate the time you have spent listing all the possible scenarios.
Basically it's a bloody mine field!
Now I'm unsure what tyres to run as I was all set to try slicks next time instead of the SP's.
I have ordered a set so will make my mind up nearer the time.
Thanks again.

 

[MacRR]

Loupe its a hell of a leap to use slicks, that'll open up a whole lot of other challenges that'll probably make things worse. I don't know how hard you were pushing when you crashed but I think you'll be best off persevering with treaded tyres and working on your technique as it's very likely it was either the second or third points Ry makes that caused the problem.

 

[Loupe]

Thanks for your input Mac, I'm new to this track game so thought using slicks may be a better option for me but now I realise that this may open up another can of worms.
Think I'll take up tiddlywinks instead (with eye protection obviously)

 

[Loupe]

Re: Pirelli Supercorsa SP

This is the type of tyre wear that you want to see from a rear Pirelli Supercorsa SP with well set up suspension.

Thanks for for the pic Ryan.
This is my tyre after 10 odd laps keeping it smooth and finding my way round.
Its not too far away from your pic but there seems to be more bits of rubber beads on mine.
What's your thoughts on the set up?

 

[fast_ryan]

Setup

Your tyre wear looks fine and doesn't suggest any issues for immediate concern with regards to rear suspension set up. Likewise the pressures you were running seem to be appropriate for the conditions as there are no signs of either hot or cold tear. Just remember the key to understanding suspension set up is being able to identify what the bike is doing beneath you and more importantly what it is preventing you from doing. This is aided by having a basic grasp of the concepts of rebound, compression and preload. When making any adjustments the best advice is to only change one aspect at a time and record what works for you and what doesn't.

 

[soofsayer]

Taken on board and open to any tips or info.
This is possibly what happened but I was looking at my front tyre this week and as the tyres were new they still felt "greasy" to touch at the sides.
Really not sure what happened tbh as I'd gone round with more or less the same lean previously and deliberately kept it smooth and controlled on the throttle coming out every corner (just rolling it on) All my braking and turning was done well before and it was in my head that I was taking it easy till the third lap was done.
I obviously want to avoid this again and I understand slicks won't prevent me sliding but my confidence has gone with my standard tyres.

I am puzzled. These bikes don't just let go like that unless something has gone very wrong and/or TC is off. Your description is nothing like pushing the limits so I'm wondering about the rubber. Where did you get the tyres from?

 

[Loupe]

Thanks Ryan, I'm trying to get my head round all this and am beginning to understand the differences.
I felt the bike was stable but would have put the front at +2 if I had stayed on track.
It was set at +1

 

[fast_ryan]

Lowside

If not for rider error another explanation is you may have been unfortunate enough to have hit a spot of oil/fluid/coolant deposited from another bike. That could explain the greasiness of the front tyre post-crash and given the fact that most 'track only bikes' used on trackdays are not subjected to scrutineering which would identify any safety issues.

 

[Loupe]

I am puzzled. These bikes don't just let go like that unless something has gone very wrong and/or TC is off. Your description is nothing like pushing the limits so I'm wondering about the rubber. Where did you get the tyres from?

They were my spare wheels/tyres I bought and were taken from a zero mile bike. I'd done about 150 odd miles on the road to scrub them in. I was nowhere near pushing my limits never mind the bike as i was purposely taking it all in.
I watched a few YouTube clips of the track lay out beforehand which was waste of time as it was a reverse circuit!
Ive seen the same lean on the road as I had on track and purposely wasn't trying to get my knee down in the morning, was going to save that for the afternoon session.
As it happened I managed to get my elbow down early on.

 

[soofsayer]

Are you saying the spare wheels came with the tyres already fitted? How long ago did you get them?

 

[Loupe]

Yes they were on the wheels already straight from the factory.
I bought them a few months ago and they were stored in my house.