motorcycle tyres front & rear

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hawkwind
Posts: 276
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Re: motorcycle tyres front & rear

Post by hawkwind » Tue Mar 19, 2013 6:32 am

long story short ....a front tyre was fitted to an old style honda comstar wheel at 160+ the rider went down ....reason deflated rear tyre .....during course inspection a rubber valve stem was found 2 miles further down the course( it was missing from the tyre /wheel assembley) ........if memory serves me correct the tyre had for front use only as do many front tyres.....conclusion events leading to the crash were unknown so new rules were inserted "metal valve stems to be used and no front tyres on rear wheels " .... as we now have reverted back to the SCTA rules front tyres can be used on rear wheels so go for it.

gary
Vehicle......................A new creation.
Designed by................Troglodyte.
Engineered/ built by......Rustic.
Financed by.................Nickles & Dimes.
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jpbyron
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Joined: Sat Jun 29, 2013 10:19 am

Re: motorcycle tyres front & rear

Post by jpbyron » Sat Jul 13, 2013 3:18 pm

Hi guys,

Thanks for a bunch of great info above. Might have saved me some money as I was about to buy some new leathers for the 2014 season.
We are building a blown fuel 100cc. Aiming at 100mph if the bottom end stays together. I have been looking for a small front tire, so we have a small front on area, like a 17 or 18, 80/80. Has anyone ever found anything this small with a high speed rating say 115mph.

Thanks JP Afflick.
APS-BF 100 109.589mph
Worlds fastest 100cc motorcycle

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internetscooter
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Re: motorcycle tyres front & rear

Post by internetscooter » Sat Jul 13, 2013 3:53 pm

jpbyron wrote: I have been looking for a small front tire, so we have a small front on area, like a 17 or 18, 80/80. Has anyone ever found anything this small with a high speed rating say 115mph.

Thanks JP Afflick.
Not exactly what you want but may be a good lead - on the Vespa Labs wiki we have a list of scooter tyres by speed rating. These companies also make motorbike tyres, so you could start at the top and work your way down.

http://www.vespalabs.org/Wiki/Vespa_101 ... FHigh_Load
Paul
---
DLRA #647
89.664 mph (aiming for 100mph+)
Vespa Labs [url]http://www.vespalabs.org[/url]

Johno Senior
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Location: Berri Sth Oz

Re: motorcycle tyres front & rear

Post by Johno Senior » Sat Sep 14, 2013 12:08 am

Hi all, ( especially ROSS)
I am at the stage of firming up my tire options, I have a dilemma, I want to run some tall skinny stuff either 21 or 19 inch but the best speed rating tyres available are V rated so up to 150mph.

The two classes I am entering MG 750 , MF 750 are both 149.3 approx records.

My bike will have less than 100hp, both the record holders were dynoed at approx 115hp, I am expecting to run around 140mph at best. :oops: :oops: :oops: :D

What will happen when I get to scrutineering ? if I have v rated tyres will I be able to run them seeing as its borderline rating versus rules.
Also what happens during the speed week if the waterbottles beat me up and up the record to plus 150

I need to know now before I spend the dollars, 21inch v preferred or do I have to buy 18 inch Z ??????????????????????/ I am comfortable with V tyres but dont want to be turned away at scrutineering.
cheers Johno

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internetscooter
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Re: motorcycle tyres front & rear

Post by internetscooter » Sat Sep 14, 2013 8:02 am

If you want certainty you can get confirmation prior...

7.B.B "Any tire deviation or the use of any non-pneumatic wheel/tire combination shall be submitted to the Contest Board, with sufficient supporting data to justify a deviation, in writing 45 days prior to an event."

I submit a letter from the tyre manufacturer and last year I submitted my dyno result showing that there was now way that I could exceed the speed rating of the tyre.

You might be able to bug the tyre manufacturer to to get a higher rating (if you are lucky). The rating stamped on the side is what they rate it at for a certain pressure and load, if you have increased pressure and reduced load, then the rating is actually higher. Also the rating is from a continuous 10 minute test (from memory) and we are only at top speed for a fraction of that.
Paul
---
DLRA #647
89.664 mph (aiming for 100mph+)
Vespa Labs [url]http://www.vespalabs.org[/url]

harky
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Location: Adelaide

Re: motorcycle tyres front & rear

Post by harky » Sat Sep 14, 2013 5:48 pm

Johno
I run a 110/80--19 ZR ( bridgstone) on the front of my old GPZ , you can thank Harley V rod for that ---------see they are good for something !!!!
the rear for me is120 /90 --18 shinko , that I have shaved , used a finely serrated blade from a key cutting machine , fitted to a 4"angle grinder
and mounted in a frame from the swing arm .
there were some z rated 18" 'but they were for the front , based on the new book that could be the go
If you want to do the shaving thing I can sent you a blade
After the shaving job --and a burnout in the shed ( the neighbour called the fire bridgade --- thought my shed was alight ) the balance was the same weight in the same place as before I started ---- was happy with that
harky
harky
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so far 120mph for$2000---imagine how fast I can go for $20,000

Johno Senior
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Location: Berri Sth Oz

Re: motorcycle tyres front & rear

Post by Johno Senior » Sat Sep 14, 2013 6:33 pm

Thanks guys , both good tips,
Based on that info its two 19 inch front wheels on the bike with a z rating , like you said good ol harley's
Also I can run a front tyre on the back and
not worry cos its a front wheel on the back as well :roll: :roll: :D :D :D :D :D :D :D :D just joking. dont beat me up
johno

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