question about B spec tires. (not looking to buy)

[dshane]

I just recently purchased Dunlop Q2s for my 09. And now I'm hearing about B spec tires and how they are made for heavier bikes like ours. Should I be concerned about not having B spec tires on my bike? I'm a little tire challenged.

Thanks for advance.

Dave

 

[not2shabby]

No. A lot of peeps run the non B spec. I've got regular PR2's on now. The only thing is the rear might wear out first, but actually the front seems to be going south first which is unusual for me.

 

[dshane]

No. A lot of peeps run the non B spec. I've got regular PR2's on now. The only thing is the rear might wear out first, but actually the front seems to be going south first which is unusual for me.

Thanks for the quick response.

 

[Geezer]

I found the PR2s run just fine without the B spec. OTOH, Pirelli Angels have an E spec which is reported to give more miles than the normal Angel. I have an E spec in the garage but have not spooned it on yet. Don't know about the Dunlop Q2s. So, my point is, it depends on the tire.

 

[NMRoadRunner]

If you run 2 up, or loaded, and travel alot of miles in a short period of time (fast), you should run the B spec tires. The side walls are designed for this type of riding while loded. I won't run anything else, It's a little more $$$, but I'm worth it. :yahoo:

 

[ShinyPartsUp]

Unless you run 2 up or are loaded heavily for high speed most of the time, you likely won't notice much. Wear might (or might not) go faster. YMMV.

 

[FJRay]

What is different about the B spec. They say it is heavier but it carries the exact same weight rating as any other 180 sieres tire. I don't see how it can be for heavier use if it isn't built stronger and it seems it should have a higher weight rating.

 

[Geezer]

What is different about the B spec. They say it is heavier but it carries the exact same weight rating as any other 180 sieres tire. I don't see how it can be for heavier use if it isn't built stronger and it seems it should have a higher weight rating.

For PR2s, the B spec has two additional plies. I don't think it adds much weight, but may stiffen the tire a bit and help it hold it's shape under stress.

 

[not2shabby]

I think B spec tires are primarily designed to lessen the weight of your wallet...

but seriously, all that stuff about 2-up, loaded down is what they say. I've done a trip with the wife unit and all the crap she could stuff in the bags and topcase and had no issues.

 

[wheatonFJR]

What is different about the B spec. They say it is heavier but it carries the exact same weight rating as any other 180 sieres tire. I don't see how it can be for heavier use if it isn't built stronger and it seems it should have a higher weight rating.

For PR2s, the B spec has two additional plies. I don't think it adds much weight, but may stiffen the tire a bit and help it hold it's shape under stress.

So...it's not a safety thing if it has the same weight rating....it's a feel/performance thing.

 

[dshane]

What is different about the B spec. They say it is heavier but it carries the exact same weight rating as any other 180 sieres tire. I don't see how it can be for heavier use if it isn't built stronger and it seems it should have a higher weight rating.

For PR2s, the B spec has two additional plies. I don't think it adds much weight, but may stiffen the tire a bit and help it hold it's shape under stress.

So...it's not a safety thing if it has the same weight rating....it's a feel/performance thing.

Okay thanks for all the replies.

So if I'm getting this correct, it's a wear and performance issue, not a safety issue. That was what I was concerned about. Thanks again for all the responses.

 

[ionbeam]

So...it's not a safety thing if it has the same weight rating....it's a feel/performance thing.

A great deal of tire life is related to tire temperature. Generally speaking, a stiffer sidewall tire will run cooler and have better tread life at some expense of ride comfort. When a B or E spec tire is mounted on heaver motorcycle it should result in roughly the same tire carcass performance as the non B/E on a lighter motorcycle. One Forum member noted that when he purchased a non E Diablo and inflated it to 6-8 psi over maximum rating it got the same tread life as the E and saved him a whole $14 over the E spec. The over inflation stiffened the sidewall and may have reduced contact patch, both of which will let a tire run cooler. The down sides are that the smaller contact patch will concentrate wear and it exceeds the pressure rating of the tire carcass. Having had a total and instant blow-out deflation that is something I wouldn't want to go through again.

Just one data point (can't draw a line from just one point...), I purchased only one tire from a dealer in decades and the dealer screwed it up. I had ordered an E spec Strada but got the standard Diablo Strada. As the way life usually works, I had to use that tire because I didn't have the time to exchange it. I have run three E spec Diablos to end of life and have gotten ~12k miles from each. I only got 5-6k miles from the non E spec. Even though the overall tread depth of the E is fractionally less, the tire carcass is entirely different from the non E resulting in much better overall tire life. I couldn't tell the difference between the non E and E until near the end of life of the non E where it was plainly worse than the E.

 

[wheatonFJR]

Okay...with ionbeam's post above...with a non-B, your safety would be the same, but you would run through tires more quickly.

 

[BwanaDik]

Is the "B" rating indicated on the tire and where? Or is it a matter of faith of getting the B spec when you order them?

I hadn't realized there was a difference. We're almost a half ton up when fully loaded on a long trip and I think I'd pay a little more in this case to simply "feel better".

 

[HYCLE]

I mostly ride 2up and overload the bike most of the time.

I have had people comment that my rear tire looked underinflated with the standard pr2.

I now have the B spec tire and with the same air pressure it deflects less from the weight.

I haven't noticed any less traction or grip in the corners with the B spec tire.

My engine rpm is also lower for the same road speed, indicating the rolling radius of the stiffer tire is larger.

I wonder how much fuel gets saved over the life of the tire?

For my riding, I think I will stay with the B spec tire from now on.

If your not riding with 600 lbs on the bike, at triple digits, 2up while dragging pegs at 60mph, then the standard spec should be just fine.

YMMV

 

[NMRoadRunner]

2 up fully loaded, running fast into a downhill sweeping turn in the mountians, an oncoming cement truck hogging half of your lane, and your ass end starts wollowing and you can't change your turn radius quickly enough, I would call this a safety issue. You can get a good set of popular brand B spec tires fro $250.00 delivered

 

[BwanaDik]

If your not riding with 600 lbs on the bike, at triple digits, 2up while dragging pegs at 60mph, then the standard spec should be just fine.

Huh, when where you behind me? :lol: :lol:

 

[johnny80s]

If you really want to know about the tire you could just call Michelin. They have an 800 number just for people that have questions about their products.

Call Us

1-800-346-4098

8 a.m. to 5 p.m. (M-F)

(Eastern Time)

 

[Miles Krase]

Just put a set of Bridgestone BT-023 GT's on Friday. Basicaly the 'B' spec, and only available in our size front and rear, imagine that. I had Pilot Power CT2's on prior. The new ones feel soooo much better in the corners 2up than the Powers. Not sure if it was just having new rubber or not, but it just felt so much lighter and nimble thatn it ever has, solo or 2up. JMO.....