AI guys for R888's in here...

[AI#97]

Well, I measured an RA1 and an R888 static unmounted and here are the results.

RA1 bead to bead measurement is 9.25", section width is 10.5"
R888bead to bead measurement is 10.0", section width is 11.25"

Those of you right on the cusp of track width beware...you just gained 3/4" in track width... I know I will be illegal with all of my current wheel inventory that clears my brakes.

[RichardP]

That's good information but I would suggest that the important measurements should be taken with the tire mounted on a rim at the proper pressure on the car with the car sitting on the ground. Unless you are in CMC. Then it's whatever loosey-goosey thing you want to make work...


Richard P.

[AI#97]

That's good information but I would suggest that the important measurements should be taken with the tire mounted on a rim at the proper pressure on the car with the car sitting on the ground. Unless you are in CMC. Then it's whatever loosey-goosey thing you want to make work...


Richard P.

I agree, but the rim being the same, the results might not be the full 3/4", maybe 5/8" or so but I also think that 9.5" rims are a necessity to take advantage of the additional width (and weight!). I am starting to consider 255's with a shorter sidewall, less weight and probably the same width of the current 275 RA1... I haven't mounted one of these tires yet but I only currently have about 1/4" of sidewall clearance to my coil over... figure a proper 9.5" rim and additional tire width...I might be close to 74" just to get it to all work?! :shock:

[Mason]

Matt,

After we talked about this on Saturday, it occured to me that Frank had already burned through a sent of R888's when he ran them for the enduro.

So, Frank, can you offer any insight into overall width versus the RA1's? You're running 9.5" wheels, correct? Track width?

[cobra132]

I am running 9 inch wheels. I will check the R888's against the RA1's and let you know as I have both mounted. FMR

[Mason]

Thanks Frank,

Matt hasn't slept in weeks from worrying about this! :)

[BSharp]

http://www.aicmctexas.com/forums/viewtopic.php?t=1363&highlight=

[AI#97]

Thanks Frank,

Matt hasn't slept in weeks from worrying about this! :)

I am sleeping just fine since I won't have to worry till 2010! ;)

[AI#97]

http://www.aicmctexas.com/forums/viewtopic.php?t=1363&highlight=

I recall Bud's first outing on them as having a SERIOUS tire rubbing problem on the front fenders....but they looked sexy.

Bud, are those 9" or 9.5" rims....?

[BSharp]

http://www.aicmctexas.com/forums/viewtopic.php?t=1363&highlight=

I recall Bud's first outing on them as having a SERIOUS tire rubbing problem on the front fenders....but they looked sexy.

Bud, are those 9" or 9.5" rims....?
9"

[cobra132]

R888's are 5/32 wider than RA1's on the same 9 in wheel and same pressure. Measured with wheel not on car, re not loaded. FMR

[AI#97]

R888's are 5/32 wider than RA1's on the same 9 in wheel and same pressure. Measured with wheel not on car, re not loaded. FMR

Frank, GREAT info. Any chance you can bring that set to ECR? Seems you are the ONLY guy in the US of A in AI that has mounted and run on the R888's.

It would be outstanding if we could NASA TX to allow a few extra "test sessions" so we can give some input to National AI directors about the tire and such. Also, if anyone has a 9.5" rim, we need to mount and measure the width compared to an RA1. Apparently again, we are the only ones even close to doing this and figuring out our problem with track width for next year.

So far, between the data Frank has given, Bud and several other reviews about the tires "walking around a lot", it sounds like the R888 is more of a "balloon" type tire requiring a ton more air pressure, or wider wheel as it has a softer and pinched sidewall. This is going to affect spring rates and shock valving too... :cry:

Anyone who has a portable Data Aquisition, it would be great to bring it to the track and do some testing if Frank is cool with being the test bed!