Problem: DOT tires on Challenge wheels

Are you kidding? Get a new tire guy. I have run R6 and all kinds of slicks on 355c wheels and previous hoosier dot's and kumho's. I mount my own tires with my own machine. Ditch the water based tire mounting soap. Make sure they are not mounting the stiff beads with WD40. Use a dry mount non-water based tire mounting soap.

 

Your "tire guy" is a...um....perhaps should be in a different line of work.

The Challenge rim, and the stock rim, and the Hoosier tire all have the same bead shape, as required by Federal Law. (DOT approval doesnt happen without it)

The R6 is designed as a race tire, and sold as a race tire. The sidewall will leak small amounts of air, because light weight is more important to a real race car than the convenience of checking your tire pressure every month or so.

Fill up your tires to the recommended pressure, and spray soapy water on the sidewalls. You will see little bubbles everywhere. This is just part of the price you pay for less rotating weight.

reference:
http://tinyurl.com/36eczr

Note that US and European standards are intentionally identical. The rim will usually have a "JWL" stylized logo in the casting.

JM

 

I have 355C rims with Michelin PS2 street tires and have not had to fill my tires for a year. Even after a track session.

 

I have Challenge rims with Pirelli P Corsas and have no problem.

 

Make sure that the tire size is correct for the wheel - each tire has a range of wheel widths onto which it is designed to fit, with one width being listed as the "ideal" width. E.g., a tire might fit 9.5"-11", with 10" being ideal. So make sure that the width is correct for your wheel.

Also, because low profile racing tires are so hard to mount, tire guys typically use a LOT of lube to get it onto the wheel. Which is fine, but try to make sure to clean off as much as possible before "popping" the bead onto the rim. This will help reduce the amount of tire "slipping" around the wheel.

Overall, I don't know of any reason why a properly fitted R-compound tire should not work well on the wheel, so I'll disagree with your tire guy on that point.

Get a large tub of water, and lower the wheel/tire into it. Look for bubbles to form where the leakage is occuring. Make sure that it's not a problem with the valve (leakage there is not uncommon, especially if it's a cheap crappy valve), and make sure you don't have a crack in the wheel itself.

But since it's BOTH rear wheels, and you've not had problems with the fronts, I suspect that you may have just ended up with incorrect tire sizing. What size are you running?

vty,

--Dennis

 

I have 2 sets of Challenge wheels. One set has street tires, and the other has Hoosiers, and neither set lose air.

 

Well, that size looks to be right.

The Hoosier R6 in 295/30 ZR18 has a rim width range of 9.5-11", and a Measured Rim Width of 10", so that should work well with your 10" rear Challenge rims. From tirerack.com:

>The measuring rim width is the industry standardized rim width upon which the tire must be mounted in order to confirm it meets its dimensional targets. Because the width of the rim will influence the width of the tire, a standard rim width for every tire size is assigned and must be used. This standardized measuring rim width allows all of the tires produced around the world to meet the same dimensional standards and therefore, be equivalent with regards to their physical size. The measuring rim width is sometimes referred to as the tire's "design rim width".

I don't know what else to tell you, aside from that I can't believe that it doesn't work. I'm strongly inclined that there is a problem with the installation, rather than a compatibility issue. Have you called tire rack? They can be very helpful in these situations.

vty,

--Dennis

 

I've run several sets of Michelin Pilot Sport Cup DOT tires on my Speedline Challenge wheels (225/40x18 front, 295/30x18 rear) with no problems whatsoever. My tire guy (Ernie Bello Motorsports Tires in West Palm) has never had any trouble getting the bead to seal.