ANOTHER tire thread

[sixstring]

I tried the searh button! REALLY! But I'm still a bit confused:

So I've read that many people have used 150 rears whether the bike is a commuter or a racer. The most popular tires seem to be the Bridgestone BT-016.

Now, I was about to order a set of Michilen Pilot Power's in 120 front 150 rear when the shop owner gave me an earful about how dangerous it is because the 150s would give you less contact with the road. As far as I understand it, because the tires are pinched, they are more round. And because they are more round, you actually get LESS rubber touching the road.

So can someone in very simple terms, explain to me why is it that the 150s will perfom better than a 130 or 120 of the same model? I'm less concerned with the additional weight and flickability of the bike, and more concerned with grip and contact with the road.

Cheers

[Alex]

http://www.ninjette.org/forums/showthread.php?t=38470
http://www.ninjette.org/forums/showthread.php?t=34925
http://www.ninjette.org/forums/showthread.php?t=33262
http://www.ninjette.org/forums/showthread.php?t=15074

[sixstring]

Hey Alex,

I've seen three out of the four threads you've got there. The most useful being the first one.

I guess what I'm having trouble coming to grips with is conflicting reports of 150 rear tires improving your performance vs 150 rear tires blotching performance.

I mean the explination for 150 tires being rounded due to pinching which results in less contact with the ground makes some sense, althought its difficult to visualize. On the other hand it seems lots of racers use 140s and 150s.... and if they're performance is good enough for racing, its gotta be good enough for street use right?

I'll have a more in-depth read through the postings on ninjette.org but in the mean time, if anyone feels they can contribute to whats already been discussed, please do so.

[Alex]

150's crammed onto a rim made for 130's just don't fit well. They cause the profile to be taller and pinched with most tires, meaning that in some cases there will be less rubber than one would expect at certain lean angles. 150's are designed for wider rims. Your mechanic isn't blowing smoke, he's trying to keep you from doing something that just isn't recommended (going up 2 sizes on a rim that's barely wide enough for 130's).

That said, there are stickier tires available in the 150 size than in the 130 size, so for people who spend much of their time testing the ultimate grip at full lean, they may see better performance out of certain 150's in certain situations. Best case would be equally sticky tires in the proper profile, but that best case may just not be available.

Originally Posted by sixstring

On the other hand it seems lots of racers use 140s and 150s.... and if they're performance is good enough for racing, its gotta be good enough for street use right?

Two completely different animals. On the track there are things that don't matter very much. Like predictable wear, straightline stability (for the most part), comfort, etc. On the street there are things that don't matter very much. Like ultimate grip level, max lean angle, etc. At anything close to sane speeds, the ninjette can corner with its pegs and/or kickstand mount dragging on the ground all day long, with the stock 130's it comes with. Anything else is a bonus.

As you've seen in the other threads, there are some tires that work OK in that larger size, the most common one being BT-016 in 150/60/17. There may be others. There are some that do not work well at all in that larger size, such as the BT-003's. The good news is that the 003 is available in a 140, which is quite a bit closer to the stock profile.

These tire threads get, well, tiresome because at the end of them, many people are just going to put the widest darned tires they can convince somebody to spoon onto the bike because it's perceived to be more fashionable, no matter what the actual rideability or performance consequences.

[RaceBikeRentals]

150 rears are fine. 99% of street riders will never use the edge of the tire anyway. Smartest tire is the BT003RS 140, as Alex says. If you don't mind not having the phat look, its the way to go.

[sixstring]

Thanks for your reply Alex,

So if I understand you correctly, the reason why some people find 150s to be superior to the 130s is because there is a greater selection of 150 tires and some of them are made of better/stickier materials. In other words the stickiness of the tires compensate for the pinched profile.

So my only local option for 130 tires are the Pirelli Sport Demons. Can anyone comment on those vs the BT-016?

[sixstring]

I'll have to see if anyone dealers in my area carry the BT003RS 140

*edit*
If I go with the BT003RS 140, what front should I use? 110? 120?

[Alex]

Originally Posted by sixstring

So if I understand you correctly, the reason why some people find 150s to be superior to the 130s is because there is a greater selection of 150 tires and some of them are made of better/stickier materials. In other words the stickiness of the tires compensate for the pinched profile.

IMO, that's pretty much it. The only thing to add is that actual tire sizes vary from manufacturer to manufacturer, and even from tire model to tire model. I.E., even if two different tires are marked as 150/60/17, one may in fact be noticeable larger than the other. A "skinny" 150 seems to fit OK, while a "wide" 150 doesn't work well at all. BT-016's are an example of the first, 003's are an example of the second.

Originally Posted by sixstring

I'll have to see if anyone dealers in my area carry the BT003RS 140

*edit*
If I go with the BT003RS 140, what front should I use? 110? 120?

Any tire shop should be able to order whichever tires you like, and these are all available mail order pretty easily as well. I can't comment on the 110 vs 120 in front, other than it's unlikely the 120 will provide better performance. It will likely slow steering feel, as it will be a bit heavier. It's unlikely to rub the fender or cause any other clearance issues, even though the rim is sized for the 110's.

[RaceBikeRentals]

110 front

[Momaru]

I don't have a reference for the BT-016's or have track time (hope to remedy this summer), but the sport demons (110 front, 130 rear) beat the snot out of stock tires for street performance.

[kkim]

Originally Posted by Momaru

I don't have a reference for the BT-016's or have track time (hope to remedy this summer), but the sport demons (110 front, 130 rear) beat the snot out of stock tires for street performance.

which stock tires did you have?

[Momaru]

The Dunlop Arrowmaxes

[Alex]

I found the Dunlops to be fine, but like you I prefer the feel of the Pirelli's on our ninjettes. They feel much softer, with more of a solid connection to the road when leaned over. I'm not sure ultimate grip is that different between the two, but even now that the 130/17's for GT501's are available, I'll continue to use the SD's for the foreseeable future.

[Momaru]

My dunlops were constantly giving out on me in the rain on roads that the SDs stick to without missing a beat. Even went back to check for oil, etc several times thinking "that shouldn't have happened." That's on the top o' the list of what sold me on the pirellis.

[250rStar]

i have the dunlop gt501 on the rear a 150/70/r17 and it barely fits but it does!! haha and i noticed that it did put the rear up a little but after a day i'm used to it and it looks great feels great i still very much have the flickability that everyone says you loose so i don't know what they are talking about! it feels alot smoother then the stock tires and and feels like there is more grip when cornering. could be wrong but like i said it FEELS like it

[sixstring]

Hey guys,

So I had a talk over the phone with my regular tech, and he says the Pirelli 130s are the way to go. The BT003RS, while good for the track, isn't recommended as a road tire because it performs poorly in the wet.

He also echoed the fact that the 250 is limited in tire selections and told me to come to the shop some day, flip through the catalog and see whats available. In the mean time, he can get ahold of a Pirelli 130 rear but the 110 front is out of stock. Can I swap out my rear tire for the time being and continue to use my stock front tire until a new one arrives? Will there be safety issues?