AMCC ART Day, Saturday 9 November 2013

[p.dath]

The next AMCC ART day is on this Saturday!
http://amcc.org.nz/advanced

I'm joining group 3 for the first time, and feel a bit nervous, but I have done a lot of group 2 sessions, so time to move up. This will be the first "real" riding I have done this year. I'll have to blow out the cobwebs, and remember to start riding properly again - skills that tend to get lost when commuting and doing easy riding.

I think I will leave the North Shore (Takapuna) around 6:30am if anyone else is interested in meeting up to ride out there.

[nzspokes]

I will be the mobile chicane in group 1. My first time out on the bike. Still trying to work out tyre pressure etc.

Im chucking mine on the trailer, easier to bring all the bits back that way.....:baby:

[p.dath]

I will be the mobile chicane in group 1. My first time out on the bike. Still trying to work out tyre pressure etc.

Im chucking mine on the trailer, easier to bring all the bits back that way.....:baby:

Haha. They will talk to you about tyre pressures in group 1. Take a pressure gauge and pump if you can - especially since you have the luxury of a trailer.

[nzspokes]

Haha. They will talk to you about tyre pressures in group 1. Take a pressure gauge and pump if you can - especially since you have the luxury of a trailer.

I trail ride, pumps etc are always in the car. Along with funky smelling boots.:sick:

Hope im not to slow for group 1......

[vinducati]

I know that they like headlights taped up.
but on my Dattona 675 the heats causes damage to the lens.
Pulling the fuse is no good as it is shared with the starter motor.
Do you have to do this?
Cheers

[nzspokes]

I know that they like headlights taped up.
but on my Dattona 675 the heats causes damage to the lens.
Pulling the fuse is no good as it is shared with the starter motor.
Do you have to do this?
Cheers

Im gunna just pull the bulb. But yes you have to tape all the glass.

[p.dath]

I know that they like headlights taped up.
but on my Dattona 675 the heats causes damage to the lens.
Pulling the fuse is no good as it is shared with the starter motor.
Do you have to do this?
Cheers

Generally anything that is glass should be taped up so that if you have an accident you don't leave broken glass all over the track. What I have done on other bikes is just pull the wire plug off from the back of the bulb.

I also don't cover the entire lens in tape, I normally just put a couple of strips across it so that most of it is held together should the worst happen. You may well find this allows enough cooling.

[nzspokes]

Ive just been checking my bike, my front brake pads have about a 3rd left. guess I better get some new ones. Sigh.

[Kiwi Graham]

Ive just been checking my bike, my front brake pads have about a 3rd left. guess I better get some new ones. Sigh.

Good idea, and just to let everyone know Cycle Treads wont have their shop there on Saturday due to all hands being on deck in the refurb of the Barry Point road premisis.

KG

[nzspokes]

Do I need to remove my top box plate and mounts? Its all Givi stuff and has no sharp bits.

Obviously I wont have my top box on.

[Kiwi Graham]

Do I need to remove my top box plate and mounts? Its all Givi stuff and has no sharp bits.

Obviously I wont have my top box on.

No thats all good :)

[vinducati]

Can you pay to use a garage space?

[nzspokes]

I believe there is garages for each group.

[p.dath]

Can you pay to use a garage space?


I believe there is garages for each group.

I think if you want garage space you need to rent it from Hampton Downs. I don't believe AMCC rents any space. And I believe the reason why you see some people using garages is because they have paid themselves for the space.

I just found this note in the FAQ:
http://www.hamptondowns.co.nz/pages/226/faqs-for-bike-track-days.htm

Garages are available and can be organised on the day. It is $25 per bike for a shared garage for a day session.

[nodrog]

I know that they like headlights taped up.
but on my Dattona 675 the heats causes damage to the lens.
Pulling the fuse is no good as it is shared with the starter motor.
Do you have to do this?
Cheers

your headlights are plastic

[nzspokes]

Chucking my bike on the trailer tonight. What tyre pressures should I start out with?

[p.dath]

Chucking my bike on the trailer tonight. What tyre pressures should I start out with?

You usually take 10% to 20% off your "road" pressure when everything is measured cold. Why don't you start by lowering them by 10%.

You need to see how hot the tyres get, and how much the pressure increases by on the track to find out for sure ...

[vinducati]

30 front 30 rear.

[Gremlin]

On the other hand, bearing in mind it's your first track day, you're in Group 1 etc. I'd probably stay with normal road pressures so the bike feels familiar while you learn everything else.

[nzspokes]

Well as the parts supplierd forgot to send my brake pads untill this morning i may be running around auckland tonight looking for pads. :confused:

[p.dath]

Well as the parts supplierd forgot to send my brake pads untill this morning i may be running around auckland tonight looking for pads. :confused:

Go pick them up from the courier depo ...

[Gremlin]

Well as the parts supplierd forgot to send my brake pads untill this morning i may be running around auckland tonight looking for pads. :confused:
I have the Premier pads from the Hamilton stuff we bought...

[nzspokes]

I have the Premier pads from the Hamilton stuff we bought...

Cheers but they have turned up at the shop and the owner is dropping them off for me at 4.30. :yes:

Only just heard.

[p.dath]

I have something playing on my mind, and nothing like the wild speculation you get on Kiwibiker.


For the first time at any track day I had an accident. I'm fine, and thanks to frame sliders the bike doesn't look to bad either. It was on the corner officially known by Hampton Downs as T9. It is the left hand hair pin that has a big descent, and the corner before the big sweeper.

I was maybe within 5m of the apex down the bottom of the descent. I had long finished braking (specifically, I was not on the brakes at all), I was sitting in 2nd, and had gentle throttle on. I would estimate I was travelling at 60km/h, certainly not fast for the corner. I had done maybe 3 laps of the session (it was up to about session 3), and both tyres should have been well warm. I use standard street sport touring tyres (Bridgestones BT023's) (as I normally ride on the street, not the track). The tyres were about 12 months old, and had a lot of tread left on them. The tyres were cold inflated to 30/30. I could not see any contamination on the track surface.

And then I lost the front end, and low sided.

I keep replaying it in my mind, as I think it is 90% likely to be rider error. I think I may have just overestimated the grip I had available at the time.


But one thing keeps playing on my mind. When the bike was at rest (in the kitty litter) the marshal and I tried to move the bike further away from the track. We couldn't. The front brake lever was locked on and "tight". We ended up leaving it there till the recovery vehicle came, which was maybe 5 minutes later. When we returned to the motorcycle the front brake lever had play in it again, and seemed to be working fine, and we were able to push it out of the kitty litter ourselves.

The brakes should have been fine. Just two weeks prior I had the bike serviced (no, I am not to going to name anyone, but it was by a well known responsible trustworthy workshop). The bike wasn't due for a service, but because it was the first time it was going to going on the track I decided to have a special one off service done, and included in the service was a full brake fluid flush and replacement, mostly because it was the first session of the season going back on track.

Since the service I had done some street riding, but compared to the track, the usage was very light.

The bit that keeps playing on my mind was how the front brake was locked on when I first checked it in the kitty litter, and appeared to be okay 5 minutes later, and that I had recently had work done on my brakes. The issue with the brake could have been because the bike ended up in the kitty litter and particles got forced where they shouldn't have been. But I keep running through my mind what if the braking system had been accidentally contaminated or compromised. And I find that idea pretty scary.

Prior to this the brakes felt great. They did not feel spongy.

I think before any repair work is done I'm going to ask to have the brake fluid drained and inspected for contamination, just to try and put my mind at rest. I am also going to ask to have the front brakes inspected in general (like the front calipers).


So now I am open to the wild speculation. What do you guys think?

[nzspokes]

Bugger.

I would be checking the fluid level first as it sounds by what your saying the brakes hydro locked. So if over filled the fluid would have had no where to go. If it should have a bladder make sure that there also. If the fluid was contaminated you would have lost lever not gained it.

Much damage?

[nzspokes]

Did you work out if it was the brakes?

[p.dath]

Did you work out if it was the brakes?

Not yet. It is hopefully being looked at today/tomorrow.

[manxkiwi]

Yep sounds suspiciously like an over filled reservoir to me too.

Let us know what the 'official verdict' is.

[Timmeh:P]

I second the overfilled reservoir.

[MarkW]

My thoughts on Phil's crash:

There are only 2 left hand corners at Hampton and the downhill left hander is a proper corner. The first left hander is just a kink. So tyre temperature (lack thereof) may have been a factor still. The corner is a downhill one with a decreasing radius as you come to the end and this does really test front end grip so there may have been a combination coming into effect - a rearwards shift in body position, a counter steer load increase as the corner tightens, an increasing throttle opening and a cooler tyre all combining to give a front end washout.

I do not agree with an over filled reservoir as being the likely cause because if the reservoir was overfilled the problem would have been very apparent on the ride to the track itself or in one of the earlier sessions. Overfilled reservoirs mean that the pads are kept in contact with the disc and so as things get hotter and hotter the problem compounds very quickly - the ride to the circuit is far longer than any of the sessions at the circuit and so the front brakes would have locked on before Phil arrived. Even if they hadn't done so on the ride there unless Phil was barely using his brakes in sessions 1 and 2 and then was hitting them really hard early in session 3 the problem would have been evident in an earlier session. And with Phil in the kitty litter the front brakes would have been glowing with heat.

It is also possible that the jar of the crash caused a calliper piston to stick briefly or a bit of the litter wedged briefly in the front brake lever housing and jammed the lever. This litter was dislodged when the fiddling with the lever occurred.

Contamination is also unlikely in my opinion - again the problem would be very unlikely to manifest itself by making a brake suddenly come on - it is rather more likely to make the brakes fail rather than work excessively well.

So, sorry Phil,

Pilot error.

[nzspokes]

My thoughts on Phil's crash:

There are only 2 left hand corners at Hampton and the downhill left hander is a proper corner. The first left hander is just a kink. So tyre temperature (lack thereof) may have been a factor still. The corner is a downhill one with a decreasing radius as you come to the end and this does really test front end grip so there may have been a combination coming into effect - a rearwards shift in body position, a counter steer load increase as the corner tightens, an increasing throttle opening and a cooler tyre all combining to give a front end washout.

I do not agree with an over filled reservoir as being the likely cause because if the reservoir was overfilled the problem would have been very apparent on the ride to the track itself or in one of the earlier sessions. Overfilled reservoirs mean that the pads are kept in contact with the disc and so as things get hotter and hotter the problem compounds very quickly - the ride to the circuit is far longer than any of the sessions at the circuit and so the front brakes would have locked on before Phil arrived. Even if they hadn't done so on the ride there unless Phil was barely using his brakes in sessions 1 and 2 and then was hitting them really hard early in session 3 the problem would have been evident in an earlier session. And with Phil in the kitty litter the front brakes would have been glowing with heat.

It is also possible that the jar of the crash caused a calliper piston to stick briefly or a bit of the litter wedged briefly in the front brake lever housing and jammed the lever. This litter was dislodged when the fiddling with the lever occurred.

Contamination is also unlikely in my opinion - again the problem would be very unlikely to manifest itself by making a brake suddenly come on - it is rather more likely to make the brakes fail rather than work excessively well.

So, sorry Phil,

Pilot error.

I wish to disagree that over filling the reservoir could not be a fault. You would not be braking in the same manor on road riding as a general rule and the brakes would heat more than normal. Now if the fluid was overheating it could have been causing the brake to bite earlier in the lever stroke, so when the rider goes to use a little brake the lever bites earlier than normally expected. That could bring the rider down in the wrong situation. I don't believe the brakes were locked on as such just an earlier bite point.

But this is just one potential reason for the incident. Rider error is most likely but the brake does need to be checked.

[vinducati]

I don't really think at such a low speed the front would go unless the brakes were on.
But me, I am not an expert.
Sucks though

[nzspokes]

Was there a photograher there?

[Voltaire]

I do a bit of classic racing on my BMW R90 with lap times of around 1m27. Recently added RaceChrono to my phone and it records each lap green on accelerating and red on deceleration with high and low speed markers.
42 kmph was the fastest I get around the hairpin.( 166 past the start/finish)
At that speed with braking finished and light throttle I'm going to go with brake lockup.
My tyres are 4 years old, Bridgestone BT45's running 27 psi f/r, I can scrape the head on T6 so I don't think tyres are an issue.
I have had car brake lines in the past that would let pressure to the calipers but were starting to perish internally and slow to release the pressure.

[p.dath]

I got to go and see my bike today. I felt very nervous before hand, but is has been strangely calming.

The brake fluid reservoir is just fine. It is not over filled.

As MarkW says, it has simply been a case of pilot error. I think I simply carried too much lean angle around the corner for the speed I was going, and lost the front end. It sounds simple enough when I say it to myself.


There was another bike parked near mine they had also been in an accident. I was told that the rider was in pretty bad shape. And here I stand with not even a scratch on me.


Thanks for your support everyone. I've had a lot of positive feedback.