190x55 on a 5.5" rim...the anomaly is Dunlop

I am writing this here on the forum for comments and am sending a copy to SR via their contact option.


Dec.2011 SR,p84:wide tires on narrow rims-again.

with all due respect, I believe your stance on this topic obviously lacks the particular experience with dunlop tires to make this judgement accurately, patronizes manufacturers, speaks down to those who are not afraid to try something new to learn and evolve, is generally too CYA, and is IMHO incorrect.

I agree that mounting a 190 tire on a 5.5" rim is generally a poor match, the key word being "generally". I have used a BTO-16(50) and a Power Pure (55)and both were steep sided, put too much stress on the front tire in terms of accelerated wear and crowning, manifested larger chicken strips on the rear than on the front, and had reduced stability at lean. I was ready to come to a conclusion similar to yours until a friend brought me a 190x50 Q2 to mount on his CBR6004FI(5.5"). As soon as I looked at the arc or profile of the tire, i thought it was unique, but of course you can't be sure until it's mounted on the rim. Once mounted, it looked like a good match in terms of the rounded profile being similar to the 180s as in no steep sides, just a nice gentle and constant arc to the edges of the tire. The first ride proved that the Dunlop 190 on a 5.5" rim is indeed a good match, no, it's better than a good match, it's a great match. Geometry is not an issue as the height is close enough to the 180x55 and after a thousand plus miles of twisties, the owner says this is the best tire he's ever experienced on his bike. Riding behind him only served to confirm his claim.

Meanwhile, I was nearing the end of a failed experiment(of 4000 miles) with a 190x55 Power Pure on a 5.5" rim. Definitely not recommended. Having mounted my friend's Q2 190 and witnessed the handling improvements thereof, it was a no-brainer for me. I chose the 190x55 because my bike was geared low and increases in rear height had worked well other than the above mentioned side-effects. I now have about 800 miles on the Q2 190x55 on a 5.5" rim and this is the unequivocally the best tire I've ever had on my bike which I've ridden for nearly 35,000 miles since purchase.

Members of your staff should try the 190/5.5"/Dunlop combinations so that you can more accurately evaluate general but untimely assumptions like, "higher steering effort,slightly slower steering and reduced stability",and relative to the 50,"it's lower profile, significantly exaggerates the disadvantages that arise from using the wider tire on a 5.5" rim,......".

I have noticed this CYA, patronize the manufacturers, talking down to riders in the past and can understand to some degree your modus operandi, but i would suggest that you can deliver more accurate information in a discreet way that will still speak to the truth while not upsetting the manufacturers.

thanks, motoman64  

The letter you refer to was asking if it was OK to use a 190/55 rear tire on a Suzuki GSF1250, based upon the fact that the spec tire for the AMA XR1200 class is a 190/55 Dunlop-- not if it was absolutely forbidden to use a 190/55 Dunlop Sportmax Q2 on a CBR600F4i or your bike (not stated what brand/model in your letter). You yourself characterize that after two failed attempts at trying different brand 190-size tires on your bike's 5.5-inch-wide rear rim, that the success of the 190/55 Dunlop Q2 is an "anomaly". We're hoping you're not insinuating that it's fine to use the 190/55 Dunlop Q2 on every single bike with a 5.5-inch-wide rim based upon just your two examples?

It would obviously be a logistical nightmare to test every single combination of motorcycle with 5.5-inch-wide rear rim/Dunlop Sportmax Q2 tire to make any sort of accurate evaluation. Thus, the "untimely assumptions" such as slightly slower steering and reduced stability actually are from our experience with that size tire on the majority of the bikes with 5.5-inch rims we've tried. It's not "CYA" or "patronizing the manufacturers"...it's making an informed statement based upon the experience we have with that combination (yes, we've accidentally mounted a 190/50 rear-- which is used on the Honda CBR1000RR-- on another literbike). And if we don't have experience with it, then we must rely on manufacturer recommendations until we see otherwise.

That said, it should be noted that we have used a 190/55 rear tire (a Dunlop D209GP A) in the racetrack test portion of a previous 600 comparison test, and we in fact answered a reader question regarding that fitment to the effect that all of the 600s (obviously fitted with 5.5-inch-wide rear rims) worked fine with that particular tire on the racetrack, where the aforementioned disadvantages are worth the advantage of increased side grip. In fact, the recommended fitment by Dunlop for that particular tire/application is a 190/55.  

I got the feeling that the mag response was talking down and lecturing like some of your comments above, and it would have been good to note your positive experience with the 209gp, especially since it is so exceptional when compared to most other 190s on a 5.5 rim. This, and the fact that dunlop prefers that rim for the 211s, should have clued you in that their other tires might have similar shape/profile/dimensions, and that this might be enough to re-evaluate your previously held negative stance on this match-up.  

Recommend for every single bike??? No, but the fact that dunlops 190s' exceptional arc/profile are perfect for 5.5" rims and might be worth some attention/acknowledgement and consideration from the experts.

How many dunlop 190s are being used on 5.5" rims is anyone's guess, but i'd be willing to bet that those who do use them will not go back to the 180s except for reasons other than handling like wear or rubbing chain guard.  

We're not "lecturing" (although admittedly, we're hoping you can learn something from this), we're stating facts. The following questions are only trying to get you to understand our response to the Suzuki GSF1250 reader's letter; it's not intended as such, but whether you take it as "talking down" is entirely up to you.

Have you tried a Dunlop Q2 or a Sportmax GP N-Tec (apologies, my mistake; it was in our 2007 Bike of the Year comparison test, not the 600 comparison) on a Suzuki GSF1250? We haven't, which was why we recommended otherwise.

So because we had a positive experience with the Sportmax GP N-Tec on the CBR600RR (and on the racetrack, not the street-- that recommended fitment is for a DOT racing tire, not a street tire), that should automatically make it a point that should be mentioned on a completely different bike with entirely different chassis geometry? I'm still baffled as to why you think there should have been some sort of "acknowledgement" of this in the response to the letter pertaining to a Suzuki GSF1250. Besides the tire profile/steering geometry differences, you do know that it's not just lateral clearance (chain guard) that could be a problem, but longitudinal clearance (the swingarm pivot) as well?

As I stated before, we have mentioned and acknowledged that the 190/55 Sportmax GP N-Tec worked well on the 5.5-inch-rim-equipped CBR600RR. That you didn't read it when we mentioned this is not our fault. But we're not about to assume that just because the Sportmax Q2's "shape, profile, and dimensions" are similar to the D209, D211, and Sportmax GP N-Tec that it's an automatic "perfect" fitment on any bike with 5.5-inch-wide rear rim. Note too that Dunlop does not "prefer" that the D211GP-A be used on a 5.5-inch rim; the recommendation is basically saying it's OK to use on that size rim-- but the tire was originally meant for a 6.0-inch rim.

There are a lot of other factors in play with regards to how a bike will behave with a certain tire, and ride height is only one of them.  

Fitment specs Rear: 190/55×17 D211GP
Recommended Rim range (5.50-6.00), Best Rim (5.50),
Width (190mm/7.48?), Diameter (649mm/25.56?)
Available Compounds: 7614 Soft, 7704 Soft/Med, 6680 Med, 6838 Med+
Suggested Pressures: Hot on the warmers 23psi, or cold 21psi
Note: For street riding, follow the motorcycle owner’s manual for air pressure recommendations. For track or race use, optimal air pressures vary with track conditions but general suggested air pressures are above.  

You are correct there, my mistake, looking at outdated information on original D209GP tires.  

no problemos. since I had run two 190s with steep sides on my bike and then mounted my friends 190 dunlop on a 5.5" on his, i immediately noticed a stark difference in the arc of the tread. We chose the 190x50 because the height was close to his previous 180 which kept his gearing and geometry close to OEM. Within 50 miles, I was following him, he was riding like he hadn't been able to previously and said it was the best tire by far and i could see that this was true. I ordered a 190x55 Q2 even before my Pures were worn out because I knew it was a no-brainer that this tire was a revolution of sorts.I got about 800 miles on it and this tire on is the best for me since I bought the bike 30,000 miles ago. I run twisties and avoid straight roads and this 190/5.5" match flat rocks. None of the slow turn in, heavier steering, or lesser stability, just the opposite on all counts. Just couldn't believe you guys hadn't picked up on it, or at least open to  new possibilities, esp when it's such a departure from the norm and one that rendered you preconceptions invalid in my eyes since i had already seen and felt it. I started riding in 1963 norton and bsa, raced a desmo ducati for a bit, have been riding ever since and love it as much as when i started.  

I have a couple other minor points of contention regarding air pressure and  countersteering, but you might not be interested.

Anyway, enjoy you mag and keep up the good work. later.  

Ah, the air pressure and countersteering Pandora's Boxes...  

ya know what. pandora's box is *** Common sense, using your brain to listen, to see and to analyze the information objectively will lead you to the truth regardless of whether or not you want to embrace the findings.  It's more an unwillingness to persevere long enough to reach a reasonable conclusion which then must be tested and revised as required. Perseverance with determination will demystify a very high percentage of the enigmas of pandora's box and that IMO is precisely the job of those who choose to call themselves reporters.  

You feel maligned and self-righteous because your holy grail discovery of using a 190/55 on your particular 5.5-inch rear rim application wasn't mentioned in the response to the person with the Suzuki GSF1250, and/or hasn't been featured in the magazine to your satisfaction. As I've already explained, we couldn't recommend to the GSF1250 rider that he should try a 190/55 Dunlop Q2 just because we had good results with the D211GP N-Tec on the CBR600RR, or that the 5.5-inch rear rim is the specified width for those particular DOT race tires. And simply going by the fact that the profiles look similar isn't enough for us to just recommend to anyone with a 5.5-inch rear rim that the 190/55 Q2 is a "perfect" fitment.

We simply don't have time to go through the various combinations of tires and bikes to find determine if every single application is workable or not. There are a ton of variables involved, including the suspension settings and riding styles of a particular rider. And contrary to what you might think, our time is a very limited resource with the tiny staff and myriad magazine/website duties we have to take care of.

It's easy for you to postulate arbitrary accusations such as "an unwillingness to persevere long enough to reach a reasonable conclusion which then must be tested and revised as required" because you aren't here dealing with our workload. We can't be capriciously opinionated about the majority of our subjects and writing because we have the responsibility of riders following our every word and recommendation.

I use the term "Pandora's Box" because everyone has their own opinions about recommended air pressure, and most especially countersteering. People can go on ad nauseum about whys/whats/hows, dissecting it any number of different ways, and everyone has their own opinions about how we've covered it (obviously...). But I simply don't have time to endlessly debate those opinions unfortunately. Thank you for voicing your opinions, but judging by your last post, I think this thread has reached its end.