# HO Urethane Rear Tires



## Sir Slotsalot (Jan 23, 2010)

Discover what the bigger scales are running on. Urethane rear tires have great grip and do not collect dust or debris like silicone. Urethane maintains grip during the race and requires less cleaning between heats. Here's the link:

http://www.slotcarexpress.com/Products.html

Just click on "Tires"


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## neorules (Oct 20, 2006)

Sir-- whats the I.D. on the urethanes for ho?


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## Sir Slotsalot (Jan 23, 2010)

Neo,

I have two profiles for Tomy & BSRT cars, designed to press fit on a .275" dia slip-on style hub. For AW T-jets, I have tires designed to press fit on a .1875" dia hub. Trying to "mic" the actual i.d. of a soft tire can be a little "sketchy" with just a caliper and the naked eye. Sizes and applications are explained in detail on the web site. Hope this info helps you.


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## neorules (Oct 20, 2006)

Do they fit on a. 250 hub and come out smaller without slipping? How a bout a .237 hub? will they slip? I had been to the website and came away with these questions.


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## Sir Slotsalot (Jan 23, 2010)

Sorry, I don't have anything for .250" dia or smaller right now. I may in the future if the demand is high enough. Thanks for the look anyway.


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## slotbubba (Jan 28, 2010)

I'm really hoping somebody will start testing out urethane coated sponge tires.....might be the next "big" thing.

Anybody been doing this?


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## alpink (Aug 22, 2010)

Rabbit Racing was until Willy died some time ago. I don't think Harvey is interested in making tires. please, let us NOT get into a discussion about the brief period when Zach took over the fine Rabbit Racing name. we need to further the hobby not destroy it. perhaps Harvey has some of Willy's notes around and will make them available?


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## slotbubba (Jan 28, 2010)

Did Rabbit make them only for the magnet cars? 

Yeah...we need to move ahead that is for sure.

I would love to see urethane coated sponge for Tjets.


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## tjetsgrig (Nov 1, 2009)

Harvey gave me a set to try out on my outlaw tjet a few years back, from what I can remember, they performed well.

JS


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## Sir Slotsalot (Jan 23, 2010)

Have added a "tall" profile for drag cars since the last post.


http://www.slotcarexpress.com/Products.html

Just click on "Tires"


Slot Car Express is a proud sponsor of Hobby Talk


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## Hornet (Dec 1, 2005)

Kewl Kihm:thumbsup:

Does anybody know the charactistics of a urethane tire.
Do they get firmer like a slip-on silicone tire,the more you stretch them,or do they stay roughly the same firmness??

Basically does the durometer reading get higher the more you stretch them

Rick


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## Mexkilbee (Apr 17, 2008)

From what I've experience with the 1/32 urethane tires, the more on and off, the rim, the looser the tire gets on rim. In most cases, Tire splits before this is noticable. Urethane Tires are more fagile in this on & off rim operation than silicone tires.
The HO urethane tires I have used (stock sized T-Jet) where fine on stock or single flaged rims. but did have the tendency to rip/tear going on double flanged rims. Once on, I learned to leave them on. If I had to take off, I went about it knowing they would not survive, if they did....bonus. 
(KRD Tires, I believe. great grip like PVT/AML silicones, but more give for drifting around the corners)


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## Hornet (Dec 1, 2005)

Actually looking for info on their hardness factor.
Do they get harder when you put them on a bigger rim.
A slip-on silicone tire gets firmer when you put it on a bigger hub.
Ie: on a 250 size hub they're classed as soft,put that same slip-on silicone tire on a 300 diameter hub,and it becomes a lot firmer:thumbsup:


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## Sir Slotsalot (Jan 23, 2010)

Rick,

My tires are made using a 40 durometer material. I don't believe they get harder when stretched on an over-sized hub. That feature is a "plus" as it helps maintain traction. I personally leave tires on the rim until they expire. Slip-on tires are "easy" on the budget. I keep a good supply on hand for replacements.


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## tabcomary (Jun 2, 2010)

To split hairs, durometer measurements are taken on material samples in an un-stressed state. Once you put the surface of the tire in tension by stretching it over a rim (notice that the diameter gets larger), you no longer have the same material state. 

It would be interesting to measure the durometer hardness for several tire materials in both their stressed (actually the "apparent hardness), and unstressed states (mounted & unmounted) to see how the value changes. 

I have an old durometer, but I am not very good at using it. I will practice-up a bit after the holidays and attempt a few tests to see what the relationships are for a few different tire materials.

Merry Christmas & Happy New Year Everyone!


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## Sir Slotsalot (Jan 23, 2010)

I was going to "get into" that with Rick but you beat me to it. LOL! Some test criteria would be great. Look forward to your efforts. Happy Holidays!!


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## tabcomary (Jun 2, 2010)

I was just reviewing some of the test procedures. HO tires are probably too small to get reliable measurements on. I have some fairly thick 1/32 tires in a silicone compound, and in a urethane compound. They will probably be the test items. Two different compounds on 3 or 4 different mandrel diameters, reporting mandrel diameter, tire diameter and durometer reading. That sounds like a full day's work. Expect it in early January!


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## Hornet (Dec 1, 2005)

LOL,it does sound like work,but it'll sure be appreciated:thumbsup:.
Thanks
Rick


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## tabcomary (Jun 2, 2010)

My attempts to measure tire hardness have not gone well. I expect it is a combination of an inexperienced operator, old equipment, and inconsistent materials. I am trying to find a more modern tester, and an experienced operator to see if I can get more consistent results. Sorry for the delay!


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## Hornet (Dec 1, 2005)

Thanks Tab.

Your efforts are very appreciated:thumbsup:
Rick


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## Zagabond (Feb 3, 2008)

Is anyone offering these new tires for a standard tjet hub?


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## Sir Slotsalot (Jan 23, 2010)

There are slip-on urethane tires available for JL/AW T-Jet hubs that measure .1875" dia x .2125" wide. The mounted tire diameter is .400". Available from Slot Car Express:

http://www.slotcarexpress.com/HO-Tires.html
[email protected]


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