More on tyres

[Allan]

Not posting to offend anyone, just an update on what I said I would do, so heres the news.

Did a long hard ride down to Taffys yesterday, but before setting out, checked and set both tyres bang on 42 psi.

After an hours and something riding of both motorway (100 -120 mph ish) and then some twisties banging it hard in and braking hard on hot roads on a hot day, as soon as I pulled up at Taffy's I again checked my pressures.

Both tyres were now at 46 psi, an increase of 4 psi?.

So, I take it that is is the 'normal' running pressure of my Avon vipers for my body weight.

If thats the case, the next time I do a 'full on track day' I'll check the pressures after a good session, see what they get up to and then set them at 46 psi and see how it handles. Would that be right??

Any comments or opionions anyone?

Buzz

 

[Jaws]

I have a question Allan.. when you got into the twisty bits, did the bike feel and behave ok ( as far as you were concerned ) ?

I suspect the answer is gonna be yes, in which case you have answered your own quection

 

[birdinflight]

makes you wonder then

why when you go to California Superbikes track days, they always drop the psi??? I know that is what you are getting at Allan, but I seem to remember someone on here, having a go at that company for dropping the tyre pressures on his bird so much it did not handle happily at all.

 

[Allan]

I have a question Allan.. when you got into the twisty bits, did the bike feel and behave ok ( as far as you were concerned ) ?

I suspect the answer is gonna be yes, in which case you have answered your own quection

Jaws, well - yes mate, the bike did behave exactly as I'm used to, but then again it does exactly the same on circuit.

This is the thing you see, I am so used to how the bike handles, that when I'm on circuit and it begins to slide as the tyres get hotter, I'm ready for it and can counter act it - so its not a problem and I'm used to it.....

What I havent done on circuit is drop the pressure (as recommended by others earlier) to see it it stops it sliding and see if my times are increased.

So -now having found out what the 'normal' road temp/pressure is, (46 psi) I'll adjust the tyres the next time on circuit to that pressure when they have got hot and see how it feels/behaves.

Yea?


Buzz

 

[frenchuk]

Might be talking crap here... But if you worked the bike really hard on the road then tyres were already hotter than planned for their normal use as road tyres, so I'd say in not so pushed conditions they would have reached 44psi, not 46, so 44 is what you want to reach when hot if I'm correct. So you just have to cane the bitch on the track, get the rubber red hot, and then drop to 44psi, Bob's your uncle. Or not, maybe.

 

[Fat Bert]

LOL~~~~ Here we go again

After an hours and something riding of both motorway (100 -120 mph ish) and then some twisties banging it hard in and braking hard on hot roads on a hot day, as soon as I pulled up at Taffy's I took a minute to ask myself "How come I couldn't keep up with Bert?"
Buzz

and your answer is Allan?



























Hallibut!!

 

[gypsy]

well according to AVON running vipers on a bird (or similar heavy bike) on a
track day they would expect to set the tyres up at 33 psi max (cold)
You would lose straight line stability but gain in grip on the bends

 

[stan the man]

why when you go to California Superbikes track days, they always drop the psi??? I know that is what you are getting at Allan, but I seem to remember someone on here, having a go at that company for dropping the tyre pressures on his bird so much it did not handle happily at all.

BIF...i think it was blumeeni that said that his bird felt shite when cali super school dropped his pressures to 32 psi,or a drop of 25%.

 

[Allan]

well according to AVON running vipers on a bird (or similar heavy bike) on a
track day they would expect to set the tyres up at 33 psi max (cold)
You would lose straight line stability but gain in grip on the bends

Gyp's, there's no way I'm going THAT low.:t
Regardless of what Avon say or any other bugger come to that, but I will try them a little lower just for the sheer hell of it.

Buzz

 

[R2B2]

Yes, I have to agree, this subject was brought up with the Avon guys

They did intially say that you should drop tyre pressures to 31 for a track day with hard riding. But it turned out that was for a bike that normally runs at 36 psi. They did say however that they didn't really have any definitive pressures for a Blackbird on a track day 'cos they hadn't tested for it, but their opinion was a couple of lbs more..... ie - the 33 Gyppo mentions!

(they did stress this was for hardish track riding). This actually came from Pete - the design guy.

 

[Duck n Dive]

Having just read the info ref the Avon visit I read inot what was said there to be the "bleeding obvious" - which we all missed peeps.........

You can have grip in the bendy bits or you can have high speed stability.

But you can't have both so you decide which you'd like :dunno:

And the recommendations seem to be that what you'll need most is grip in the twisty bits - which I guess also makes some sense 'cause that's where you'll proly push things more compared to what you usually do.

Isn't that the same issue the racing guys face on tyre choice. it's all l'bout compromise and whatsuits you're style.

 

[R2B2]

Yes!!

Avon Pete did say that the high speed stability any of us on a Bird would loose would be inconsequential. He said the cornering was much more important.

 

[D.S.]

(they did stress this was for hardish track riding).

so it's only really applicable to 1200 Pete & Musher then? :dunno: :}
I exclude Russ 'cos he's sign the light of course

 

[blumeeni]

quote from Pete(avon)as tyre,air,and track temps vary, after a session out on track check the pressure as soon as possible you would be looking to set it at the recommended 42 42 hot
then let the tyre cool down check the pressure again say it dropped to 36psi this would then be the cold psi they would use for the track in conditions next time with similar conditions

I've done 3 levels with California super bike school they do all the tyre setting's for the pupils at 32 32
the bird felt like shit every time

the first at mondello park Ireland when conditions were cool and dry the bike felt crap wouldn't steer,it felt like the tyre wanted to roll off the rim

the second at Cadwell park a hot day like we're having at the mo again felt crap but once I'd done 2-3 laps it handled better but still not as good as normal.
In the afternoon I put in an extra 6psi this transformed the way she felt.

next was a few months ago at Rockingham a wet cold miserable fucking day (in more ways than one as I binned it losing the front at the hairpin :B)
again they insisted on 32 32 for all bikes

This was the worst my bird had ever felt the tyres were always cold so I checked and reset the pressure to 42 42 normal service was then resumed.
this was done after my off

Then came our RSID at Prestwold I left the pressures at 42 42 cold for the whole day
the bike felt fine :yo:

I'll be doing level 4 with cali super bike school next while not wanting to teach my granny how to suck eggs they can go fuck themselves if they think I'll be running at 32 32 this time I'll insist on setting my own psi using Avon's method and a note from my mum :}

 

[stan the man]

so your definately NOT going to be running at 42-42 next time eh pete c7u8
























:}

 

[Allan]

I'll be doing level 4 with cali super bike school next while not wanting to teach my granny how to suck eggs they can go fuck themselves if they think I'll be running at 42 42 this time I'll insist on setting my own psi using Avon's method and a note from my mum :}

As with all things, advice is only advice, if you know better from experince, then go with that.

Its all very well if the person who's giving you advice has actully ridden a BB with the same tyres and thus has first hand experince, but to talk in 'general' terms, applying the same rule and settings to all bikes just inst right.

Go with what you know best!!!

Buzz

 

[Fat Bert]

Really~~~~~

........They did intially say that you should drop tyre pressures to 31 for a track day with hard riding. But it turned out that was for a bike that normally runs at 36 psi. .....

So they REALLY know the BIRD then yet give out "advice"?

FFS If they had been "professional" surely they would have CHECKED first before coming out with across-the-board figures? :wank: :wank: :wank:

 

[R2B2]

Bert........ FFS....... this is the guy who designed the tyre!!!, who sets the criteria for their very demanding testing regime, etc, etc, etc.

I think he knows what he's talking about!!!!

 

[gypsy]

Bert knows better cos he used to be a Head rep Rob

 

[Fat Bert]

Rob~~

Bert........ FFS....... this is the guy who designed the tyre!!!, who sets the criteria for their very demanding testing regime, etc, etc, etc.

I think he knows what he's talking about!!!!

He may have designed the tyre BUT does he know the BIRD that has very specific tyre requirements?

Obvioulsy not as he gave out "professional advice" when he didn't even fecking know the correct road psi's

Sod it!!

Do what you like - bored with it all now :f :f :f