Landracing Forum
East Coast Timing Association => ECTA Rules Questions => Topic started by: jaguarsurfer on July 30, 2010, 02:38:51 PM
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im looking to build a small 125cc bike to run in a few 4 stroke classes.
im having a very hard time finding H rated tires that will work on the smaller rims IE 1.40 or 1.85.
i dont really want to run a 90/90 front and 100/90 rear on a bike so small.
what i really would like to do is run BT39ss tires like on the honda dream 50R.
but they are s or p rated.
i plan to run in the 80-90mph range.
i understand that ratings on tires are important and i would not want to ever try to run a H rated tire at 175mph but im talking about running 115mph rated tires at 90....
is there someone to appeal to and plead my case or is it just the way it is and i need to work around it?
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H rated tires are only good for up to 130 mph so they are definately what you should be using if you expect to go 115 mph. Not sure where you got your 175 mph figure from but that is not an H rated tire. 175 mph requires either a Z or W rated tire.
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I have looked a lot of places for small displacement tires (and rims) for my 1950 Harley Hummer 125cc. I hope that this information will help you. I like the 2.25x18 Heidenau M3 (H-rated racing) along with 1.60"x18 non-valenced rims. I thought that the BT39ss tires were legal off road racing tires (therefore legal). You might want to contact them yourself for more info. Here is my e-mail reply from Bridgestone:
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Hi Tom,
You can get this tire from any Honda shop, the Honda part number is 42711-NX1-003.
You can also order it from our race tire distributor - Performance Tire Service Company - phone 800-828-9143, ask for the motorcycle department.
Regards,
Kevin Hunley
Customer Service/PDIC Manager
Motorcycle/Kart Products
US & Canada Consumer Tire Sales Division
Bridgestone Americas Tire Operations
535 Marriott Drive
Nashville, TN 37214
Phone (615) 937-3334
Fax (615) 937-3431
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Also, you CAN get H-rated race tires in the US. Here is my e-mail:
Hello, I have the 2.25-18 here, No K55 and the street version of the K56. will that work? John B
Come check m out at http://www.moto-amore.com/
and www.heidenauusa.com
Date: Sat, 1 May 2010 11:17:08 -0700
From: tomsmith18@verizon.net
To: motoamore@hotmail.com
Subject: Heidenau tires (racing)
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Matching rims are available from:
http://www.discovolantemoto.co.uk/wheels/morad-non-valanced-rims/prod_143.html
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Another source for other Heidenau tires and rims are here:
http://www.emot.nl/webwinkel/index.php?act=viewCat&catId=47
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Addendum: I forgot to mention that the Heidenau 2.25x18 M3 tire comes in non-racing (NOT H-rated) and a racing version (H-rated). Be sure to get the right one. The tread pattern is 70-ish but don't fear - it works, although I'd trim the tread down some to reduce centrifugal forces a bit. Note that they recommend a 1.60 or maybe a 1.85 rim. I originally thought that was too wide, but they spec 1.60 minimum.
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H rated tires are only good for up to 130 mph so they are definately what you should be using if you expect to go 115 mph. Not sure where you got your 175 mph figure from but that is not an H rated tire. 175 mph requires either a Z or W rated tire.
Yes I understand about the ratings. That's what I mention.
I just don't think I need 130mph tires to run under 100mph
I will look into those tires. Thanks so much for the help
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they make a 17 inch race tire too?
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The tire requirement isn't based on what you think you can run. The requirement is based on the record in each class. If you bump the class record above the rating for the required tire you'll also bump the tire rating requirement for every vehicle in that class.
Pete
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Guys,
something to ponder, Cars get 150MPH on H rated Tires in the SCTA and 175 in the ECTA. why only 130 in Bike Classes? different construction?
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The tire requirement isn't based on what you think you can run. The requirement is based on the record in each class. If you bump the class record above the rating for the required tire you'll also bump the tire rating requirement for every vehicle in that class.
Pete
im sorry im new but i dont really understand what you mean.
the record in any of the classes that im looking to run in is under 70mph. maybe one or two are in the under 80mph range.
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There is only one 125cc record under 70mph p-pp
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Fred, it looks like you and I both got caught out by not checking the top of the page. This is an ECTA post. :? :? :?
Pete
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OOPs, I hate it when that happens!! :roll:
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Yeah I was just going to check my rule book for the 2009 records in the small cc classes.
Also I'm looking to run in the four stroke class too.
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Is your bike a 2 stroke or 4? While we can run up in displacement, fuel w/ a gas bike, blown if NA, modified or MPS with a production bike (yeah I know, right coast only), I don't think one can cross enter 2/4 (only ECTA recognizes that distinction). Good luck with your project. I can't find anything over V rated tires for a 19" 90/100; but I probably couldn't afford them anyway.
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I am a four stroke and only plan to run in four stroke classes
I'm having a hell of a time finding H rated tires that will fit either a 1.60/1.85 x 18
Or
1.40x 17
Wheels
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Just follow the rules, they are there for safety - YOURS. We encountered the same problem but resolved it with Avon's, available here in the states. Wave the tire rating rule for someone and watch the insurance company fold up its tent should something happen. You can have one hell of a lot of physical damage and broken equipment at under 70 mph or under 100 mph. Sorry if this rubs you wrong but this thread has no point to it. The RULES rule. John Ritter
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The tire requirement isn't based on what you think you can run. The requirement is based on the record in each class. If you bump the class record above the rating for the required tire you'll also bump the tire rating requirement for every vehicle in that class.
Pete
so since the record that im running against is under 70mph any tire is good? (rules say any motorcycle tire under 70mph)
but my plan is to run more then 70mph and i dont want to run faster then my tires are rated for (i feel thats unsafe)
or can i run 115mph rated tires in the class and take the record and be safe and with in the rules? but then that means the next runs against that time will NEED to run the H rated tires
please understand that im not trying to cheat the rules or run a set up that is unsafe.
my goal is to understand what the rule is and then see how to build to it.
but that being said i dont think it would be right to make the 70-130mph motorcycle guys run H rated tires as i feel that over kill and hard to find in the right sizes
the BT39ss tires would be nice but are RACE tires but not H
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Jag,
The Avon's will solve your problem. They are "H" rated and that is with a tube or tubeless. We had the same problem as I stated above and I had difficulty finding a tire that would work with a tube because our wheels are spoked.
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Race Tires would have a higher speed rating than a "H" street tire, so if your speed /class requires H rated or better... the race tire would be fine as I read the rules.
Charles
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I'm also building a small bike, and found some tires that are H rated that will fit my application.
I looked at one today, and didn't see any rating on it, so I didn't buy them. My question is, how/where do I find this rating on the tire? I expectd to see something like 56H, or similar, but saw nothing.
Kenda claims that they're H, but it's a long drive to Maxton, and I don't want to take any chances.
Thanks.
Edit: Its the Kenda K671, and I would be running the same size front and back. They are not marked for position.
http://www.kendausa.com/en/home/motorcycle/street/cruiser-.aspx
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most of those tires are h rated.
speed ratings are listed in the tire size.
e.g.--100/90h-16
franey
if there is no h on the sidewall, i would find another tire.
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The Heidenau 2.25-18 M3 racing
Is not only H-rated, but is designed for 50cc road racing, where speeds get up to 120mph or so. Also, don't forget that regular tires are usually made for big bikes and are a lot heavier with more plies than needed for 50-125cc bikes. Look at the weight carefully. This site:
http://www.emot.nl/webwinkel/index.php?act=viewCat&catId=47
also has Heidenau 3.00-18 K65 racing, 2.75-18 K45 racing, 2.75-17 K56 racing, 2.75-16 K55 racing and some others. The M3 is the only one I know specifically to be H-rated.
Rims are at: http://www.central-wheel.co.uk/rims/morad_rim/morad_rim.html
There are probably a lot more sites in Europe that have stuff for itty bitty bikes like my Harley Hummer.
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Tom!
Is that Trebor Crunchhog driving your avatar?
Is that from Automobili Cyclops Spa? Is that a Cyclops with the XBS-V1 the world's first V1 engine?
Where is Piero Martini when we really need him!
(http://sbiii.com/autopix/cyclops/smcartt4.jpg)
Piero Martini demonstrating full use of Cyclops' air brakes while leading the team in Cyclops Super Sports coupes-made out of magnesium Cinzano signs -- to a 1, 2, 3 LeMans victory. II Cyclops At LeMans August 1960.
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Yep. Cyclops is the only car to win the Indy 500, 24 hours of Le Mans and every other race worth winning. Thanks to the wing for downforce/traction it is easily in the 400mph class at Bonneville and is suitable as a taxi in New Delhi. My Works Harley Hummer will probably be using some of the Cyclops advanced technology as soon as I can dig it out of the debris in my garage.
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I still prefer the Pignatelli
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Tom,
Thank you for the links, they are what I wanted before buying the Avons but could not find a source in H rated. Job well done.
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I'll have to have another look at those Kendas.
I can't imagine they'd list them as H rated, and they wouldn't be.
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most of those tires are h rated.
speed ratings are listed in the tire size.
e.g.--100/90h-16
franey
if there is no h on the sidewall, i would find another tire.
Bought one today, and they look good for the money.
There is no H in the size, but beside the sizing, it says 54H, so they should be fine.
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most of those tires are h rated.
speed ratings are listed in the tire size.
e.g.--100/90h-16
franey
if there is no h on the sidewall, i would find another tire.
Bought one today, and they look good for the money.
There is no H in the size, but beside the sizing, it says 54H, so they should be fine.
yes, they should be fine.
franey
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I am a four stroke and only plan to run in four stroke classes
I'm having a hell of a time finding H rated tires that will fit either a 1.60/1.85 x 18
Or
1.40x 17
Wheels
Newbie, same 17x1.4 wheel dilemma. 3-1/2 weeks till opening day, and an unused set of P-rated Michelin's mounted up. Duro has some skinny 17's but none in the US, or on the Google. Has any one found a suitable 2.25/2.50-ish 17?
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I think the Bridgestone BT45 is the tire of choice for narrow wheel road racing.
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I think the Bridgestone BT45 is the tire of choice for narrow wheel road racing.
That puts a 100-width tire on a little Honda SS50Z. Not what I was hoping for.
I changed my class from 125 to 175, but even the M/G-125/4 was likely to break 70, so a one-pass weekend.
I saw what I think was 22/2.50-17 dragster tires on both wheels of a racer when at Maxton, 2 years ago. Legal for both wheels?
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Not sure, why don't you call the ECTA tech official?
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no rear drag tires.
not sure about a slick front on the rear.