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Rear tyre growth

Posted: Fri Jun 27, 2014 5:41 pm
by harky
A question --- to those who go -----proper --- fast
how much rear tyre growth do Busa and similar bikes get when they are doing 200 + ???
this may have been covered before , I have nt seen it if it has ! :?: :roll:
thank for any --- proper answers
harky

Re: Rear tyre growth

Posted: Fri Jun 27, 2014 7:24 pm
by Greg Watters
not enough to notice on street type tires, LSR tires about 13-19mm depending who you ask
I think the 19 is probably more accurate from contact i saw on Richard Assens bike between the tire and nearby hardware

Re: Rear tyre growth

Posted: Fri Jun 27, 2014 7:57 pm
by Stayt`ie
further to what Greg said above,, street type tyres at 50psi, LSR tyres at up to 70psi,, lower pressures may see more growth,,,

Re: Rear tyre growth

Posted: Fri Jun 27, 2014 8:39 pm
by harky
thanks for the reply ------ funny the question was aimed @ you two , thought it might be of interest to others
so you run street tyres @ 50 psi ???
do you use nitrogen ??
harky

Re: Rear tyre growth

Posted: Sat Jun 28, 2014 9:41 am
by Stayt`ie
Happy Birthday mate, you've just caught up too me, lol,,,

Yes, i run 50psi fore and aft (Dunlop Sportmax) on wind straight out of the compressor,,

Nitrogen, Tire Warmers, etc, etc, :?: , no, imho, only extra junk in the trailer that serve only to satisfy ones brain and give no extra performance value, :roll: ,, one of the "interesting nature" things about salt lakes is that no matter what the weather conditions are, the lakes surface always remains at a steady 26*,, i have been told (have no data) that the tires are cooler after a run, :?: :?: ,, but, spinning them up during a pass sure puts the heat into'em, :lol: ,,,

Re: Rear tyre growth

Posted: Sat Jun 28, 2014 1:54 pm
by harky
the thing i like about this "group "is the free sharing of information , especially from those who "know"
it is not my experience in other forms of motor sport
ps how did you know its my birthday ?
my wife quoted Clint Eastwood today , the secret to getting old is "NOT LET THE OLD MAN IN "
@ 62 Im working on that
just need to go faster before the OLD MAN gets let in
cheers
harky

Re: Rear tyre growth

Posted: Sat Jun 28, 2014 4:45 pm
by Jeff lemon
Yep 50 psi I use nitrogen but only cos its free and easy to strap a bottle in the trailer!

Re: Rear tyre growth

Posted: Sat Jun 28, 2014 7:02 pm
by RGV
Happy B/Day Harky. Check the bottom of the page for whos B/Day it is. :D

Dave

Re: Rear tyre growth

Posted: Sat Jun 28, 2014 7:16 pm
by harky
I must be loooooosing it
I dont remember doing that
any everyone thought I was an old looking 40 something !!!

Re: Rear tyre growth

Posted: Sat Jun 28, 2014 7:36 pm
by rgn
In 2015 I will be using Dunlop N-tec slicks, in 2013 I used Pirelli Superbike slicks. One set over the meet with no substantial wear to report.

The Dunlop N-tec's are said to be a zero growth carcass. Recommended pressures are 32 psi front 22psi rear on the dunlops, this is what I run at the track (road race). The great thing about the dunlops is there is no heat cycle, so the generator will only be running 50 minutes prior to a run, and we are looking at a solar system, not space... a sun powered battery unit.

On our last run in 2013, with the pirellis pressures where 31 psi front, 25 rear, at 70 degrees off the warmers, 208.153 mph.

You see people posting up photos of chunking tyres, this is because they are run cold and overinflated. When road racing we will increase the psi of a tyre slightly in colder conditions when the track temperature is down, this keeps the tyre in the temperature range, in cold conditions we go to a harder compound as this prevents cold tearing. Keep in mind the salt is a relatively cold racing surface (track temperature) irrespective of how hot is is outside

Whatever the case the manufacturer knows best, and believe me you want a contact patch.

Air is fine for your tyres, argon is a far better gas than nitrogen if you want to get fancy, and you probably have a bottle on your welding rig... great for servicing shocks as well.

Re: Rear tyre growth

Posted: Sun Jun 29, 2014 12:30 am
by harky
so while we are all in party mode
who Dynamic balances their tyres ?

Re: Rear tyre growth

Posted: Sun Jun 29, 2014 8:21 am
by Stayt`ie
yeah, back in 2006 the "one and only" tyre that i have chuncked happened to be a Metzler Racetek (way too soft) at manufactures recomended pressure, 32psi,( i think),, also the fact that the thing was way overgeared didnt help,, it was the first year that i ran the 12, went 204 so i was happy, learnt a lot, :wink:

Re: Rear tyre growth

Posted: Sun Jun 29, 2014 8:54 am
by Greg Watters
i run about 40-45 psi, but fully loaded with fuel and me on the bike we weigh 500kg , probably as much flex in the tire as a track bike at 32
and i dont like running tires designed for a 180kg track bike
so working on this sort of thing for this year d2284 goodyear radiused for a better motorcycle profile
Image

Stuckeys in Melb are able to shave tires , these LSR tires are not very round and complicates the process , but a bike tire would shave better
All thats needed is a rim that would mount in there car type machine with a tapered centre lock

I put a frontrunner on a commodore 17" space saver , but it was a tight fit as there designed for motorcycle rims
motorcycle rims are 433mm and car rims are 436mm at the bead and i dont think i want to try the 140 psi it took to seat the front runner on a motorcycle tire