BFG Rival thread -- notes, comparisons, etc

Chuck Branscomb · **Posted:** Sun Aug 04, 2013 7:17 pm

When changing out the tires yesterday, I decided to take some pictures of the Rivals versus Continental DW, etc.

First up is 245 Rival versus 245 DW, both on 8.5" wheels (these are actually 245/40-18 Rival vs 245/35-19 DW):

Here's a look at the difference in mounted section width -- the Rival measured 11mm wider than the DW:

Next up is a real shocker, to me at least -- both of these are 245 Rivals, one on an 8.5" wheel and the other on a 9.5" wheel:

I said shocker since the "rule of thumb" is supposedly, quoting TireRack here: The industry rule of thumb is that for every 1/2" change in rim width, the tire's section width will correspondingly change by approximately 2/10". I measured the section width difference at 24mm (i.e. instead of 0.4" or 10mm):

Last up is a 265 DW vs 245 Rival, both on 9.5" wheels (265/35-19 DW, 245/40-18 Rival):

The 265 DW measured out 8mm wider than the 245 Rival:

Still super happy with the Rivals so far.

Steven Carter · **Posted:** Mon Aug 05, 2013 8:14 am

thanks, Chuck! Makes me wonder whether a 235 or 245 would be a better fit on a 17x9" wheel...except they don't make a 235 and the 245 is shorter than the 255. :lol:

I noticed at the last couple of events that I can run a pressure down as low as 29 before the tire rolls over onto the little sidewall triangle, but it definitely doesn't feel good or fast at that pressure. Seems to like 35-37 much better than 30-32 on my 2750# car.

Chuck Branscomb · **Posted:** Mon Aug 05, 2013 8:46 am

Yeah, I have clue really what the optimum pressures would be. I've been running 38F/36R hot pressures, and that seems to be working out well so far. I've never allowed them to go over 39 hot. Sidewall wear is not nearly as much of a problem as I would have thought for a stock class, strut car, but I am getting some good wear at this point (i.e. I should swap the fronts onto the rears if I was going to try to get max life out of these, but I don't want to pay the mount/balance just for that).

I have 28 "normal", more or less, autocross runs on them, plus 21 runs on the high speed 1:30 length course at the Performance Center, plus 12 runs at Michelin black lake in the rain. So 49 total dry "runs" although I probably should count the PC event runs with a multiplier of some sort.

noahfleming · **Posted:** Thu Aug 08, 2013 10:24 am

I just joined the Rival club!

Sadly, I did not take nice comparison shots of the 255/40/17 RS-3 vs Rival, but if I get a chance I'll do so. The Rival did seem to be ever so slightly further off the edge of the wheel, but maybe only by a couple of millimeters. No autocross runs on them yet, I just put them on to scrub them in and get some of the release mold compound off of them, but man they feel amazing while doing some invisible slalom testing :mrgreen:

Can't wait to see how they perform at Cherry Point on the 18th.

Steven Carter · **Posted:** Thu Aug 08, 2013 11:17 am

I would really like to hear your thoughts about them, also. Good to have two STR points of comparison esp after being on StarSpecs so recently. I keep them at 35f/37r. I don't *think* I have needed to spray them, but I did for the fifth and sixth run at ZMax out of habit. They were hot but not greasy feeling, and I could keep my hand on them a good 10-15 secs without feeling like it was burning hot. I should've used Jeremy's pyrometer to check temps but forgot....oh well.

The fact that Jeremy whooped up on me using old RS3s shows you (a) how much practice I need and (b) I think the RS3 may still be a very competitive tire. With you and he being so close after ZMax (then adding in the others) it will be a treat to see STR compete at MCASCP.

Gwen Habenicht · **Posted:** Thu Aug 08, 2013 1:16 pm

I've enjoyed reading this thread. We've been very pleased with the Rivals on the Audi. I've run them in L2 at several Pros and they've handled well. The Audi weighs 3200 pounds and we run pressures much higher than what you've mentioned here. Depending on the surface and weather conditions, never lower than 40F and as high as 70R. :shock:

We've also run hot laps with them to the point that you really couldn't put your hand on them and they continued to perform the same. We didn't keep an accurate count on runs with them, as we do with R Comps, assuming that we wouldn't need to, but they have many, many-well over 50-on them and they haven't fallen off, as far as we can tell, and we're still on the first set.

Steven Carter · **Posted:** Thu Aug 08, 2013 1:46 pm

Gwen Baake wrote:

We've also run hot laps with them to the point that you really couldn't put your hand on them and they continued to perform the same.

Good to know....thanks!

Chuck Branscomb · **Posted:** Sun Aug 11, 2013 4:52 pm

Gwen Baake wrote:

I've enjoyed reading this thread. We've been very pleased with the Rivals on the Audi. I've run them in L2 at several Pros and they've handled well. The Audi weighs 3200 pounds and we run pressures much higher than what you've mentioned here. Depending on the surface and weather conditions, never lower than 40F and as high as 70R. :shock:

We've also run hot laps with them to the point that you really couldn't put your hand on them and they continued to perform the same. We didn't keep an accurate count on runs with them, as we do with R Comps, assuming that we wouldn't need to, but they have many, many-well over 50-on them and they haven't fallen off, as far as we can tell, and we're still on the first set.

Wow, amazing that you guys are running such high pressures, so I guess it's hard to compare cross-platform. On the M3 when pressures got much over 40, I noticed more skittering up front in slow turns. The M3 weighs about 3550lbs, and it's almost perfect 50/50 plus add 195 for me in the car.

In the GRM test on a totally different car (89 Civic) with a much different size (205/50-15), they claimed "The Rival was more typical with peak performance at around 32psi - though both higher and lower pressures were not far off the clocks."

When Jim told me the TT was somewhat loose in the rear and liked to rotate, after I asked him if it was a plow horse, he didn't mention the rear pressures as high as 70!

Gwen Habenicht · **Posted:** Mon Aug 12, 2013 8:32 pm

Chuck Branscomb wrote:

When Jim told me the TT was somewhat loose in the rear and liked to rotate, after I asked him if it was a plow horse, he didn't mention the rear pressures as high as 70!

Actually, the 70 psi is extreme, but the car is very well balanced, and all three of us like it loose, but manageable. Now that the alignment issues are worked out, the Audi is a hoot to drive. As the "blond" of Grab & Go, and not the one who makes decisions regarding tire pressures, it seems to me that one can read all the reviews, but in the light of day, just trying different pressures...(on different surfaces, and in different weather conditions)in at least 5 psi increments, is the best way to find how the tires work on your car, and for your style of driving. Just my two cent's worth. (not actually worth the price, really.)

Chuck Branscomb · **Posted:** Tue Aug 13, 2013 8:30 am

Gwen Baake wrote:

Chuck Branscomb wrote:

When Jim told me the TT was somewhat loose in the rear and liked to rotate, after I asked him if it was a plow horse, he didn't mention the rear pressures as high as 70!

Actually, the 70 psi is extreme, but the car is very well balanced, and all three of us like it loose, but manageable. Now that the alignment issues are worked out, the Audi is a hoot to drive. As the "blond" of Grab & Go, and not the one who makes decisions regarding tire pressures, it seems to me that one can read all the reviews, but in the light of day, just trying different pressures...(on different surfaces, and in different weather conditions)in at least 5 psi increments, is the best way to find how the tires work on your car, and for your style of driving. Just my two cent's worth. (not actually worth the price, really.)

No, that's great advice to me anyway as I tend to be stuck in the realm of set it to what has worked (somewhat?) in the past and leave it there. With so few runs to try to experiment at any given autocross, I find it *really* hard to get much out of fine-tuning pressures when I'm just trying to remember and drive the course.

Good point on 5psi jumps though since if I was going to try to play with pressures at an autox, larger increments like that make sense.

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BFG Rival thread -- notes, comparisons, etc

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