Phew Ottawa, I will re-read that when I have insomnia.
Traction = adhesive friction per the MW dictionary. I simply don't get how pointing the grooves the other way on the front tire increases it. Why don't racers use them instead of slicks if the traction is so much better? Why don't all front tires on bikes (and cages for that matter) utilize the idea? I am surely overly simplifying but what can I say? I'm simple minded.
yeah that's your problem, you're oversimplifying this. track slicks and street tires are like comparing apples to oranges. first of all the track slicks use a much softer compound than street tires. you wont get the mileage out of a track tire that you will out of a decent street tire. just not going to happen.
second of all, track tires are developed with a specific purpose in mind, be it for a specific dry temp, wet surface, tight courses, long straight courses, etc etc and they change/use specific slicks according to the track condition of the time. street tires on the other hand are designed to handle a much wider range of conditions and perform across the board.
to complicate things farther, you also have to consider surface conditions and materials used in the construction. in most places you'll find better surface conditions with better materials as well as even better construction on the track and this is rarely ever the case on a surface street/highway. then theres the groves, tar snakes, pot holes, etc etc.
as for car tires and motorcycle tires, that's like comparing apples to grapefruit, completely different application and designs incorporated to handle the different stresses that are experienced.
when you look at the PR2's they're designed to handle not only wet and dry, but also mileage as well as everything in between. you just have to let go of comparing to slicks because it just doesn't work that way. you can take a set of PR2's and run them on the track, then ride home at the end of the day, rain or shine. doing the same thing on a set of slicks is well, slick and asking for a lot of trouble, more so if it's wet.
My cognitive ability is limited. I am not scared to admit it. I do know one thing though: Without data all we have is fucking conjecture. I can admit to not being a rocket scientist but you clowns also have to realize that I ain't gonna believe your Internet posting ass without some kind of data.
I don't dispute Michelin's response or expertise. I also don't dispute some of the engineering explanation of why it may be. What bothers me is that you guys really have no data but yet think you know something 100%. There are other proven, well-rated tires out there with the treads in the same direction (BT-023, for example).
The general premise that front tires on bikes or cars should give improved traction under braking makes sense to me. What doesn't is that a lot of front tires (bike and car) have the same tread up front. I don't need the answer and won't lose any sleep. Just don't tell me I have to believe something because an anonymous Internet poster says it's so.
Why? Everyone else clearly already understands it. Just ban me because I want to go outside and play in a real sandbox. There's a bug in my margarita.
You ask a question and get several responses, some opinions and some facts(assumed), and complain about it? Why bother asking in the first place? Are you expecting someone here to quote an encyclopedia for you? If you're going to bitch about the responses you get here, don't bother asking the question next time, do your research and if you feel like sharing the results post them for everyone's benefit.
I've read several design books for motorcycles. And pay a great deal of attention to any technical write ups anywhere I can find them, especially on tires. And trust me they aren't too easy to find. Quality car and car tire design books are much easier to get a hold of.
As for the slicks not having tread. Tread degrads traction on dry clean payvment. Plain and simple.
Road tires must have tread for legal reasons. And because tread does help shed water. Any kind of tread will help shed water relative to no tread at all. So priority, on sport tires, it placed on tread stability in the name of better wear and feel. On wider, flatter cross section tires one might see tread that faces "forward" but that is on bikes that likely don't brake has hard with the front tire (cruisers, heavy weight tourers). And have harder rubber that wears more slowly and deflects less (the less deflection from harder rubber is a guess) and due to the type of bike it is more likely to be used in poor weather.
I'm drawing some stuff. If I can get the picture to take or the scanner to work I'll try and put my thoughts into pictures. HOpefully it will make more sense then.
OK. See if anyone agrees with this. Hard to fit on one page. The logic kinda flows from top left, to top right, to bottom left, then bottom right and then the bottom note about deflection.
Note that the bike tire is unique compaired to a car in that depending on what your doing a different area of the tire is or is not touching the ground. Hard breaking only the center, mile braking and mild turning half way between the center and the edge is touching. Full cornering with no brakes one is on the outside edge. In my example on the left side of the tire. Though it shows on the right side because one is looking through the payvment as if the bike was riding across glass.
I remember thinking to myself once, "why don't the front tires on RWD vehicle get flipped around like on motorcycles to help with braking?"
Then I realized, since car tires are so flat the backwards tire would channel all the water to the center and essentially turn the front tires into skiis
"Security is mostly a superstition, it does not exist in nature: avoiding danger in the long run is no safer than outright being exposed. Life is either a daring adventure or nothing."-Helen Keller
Ha. If I had half the creativity that dude had I wouldn't be fideling around on motorcycle forums.
Oh well. I tried. Its not a question that would be easy to answer over the phone, let along on a forum. Only way to have a shot at it is face to face. With a big chalk board.
Ha. If I had half the creativity that dude had I wouldn't be fideling around on motorcycle forums.
Oh well. I tried. Its not a question that would be easy to answer over the phone, let along on a forum. Only way to have a shot at it is face to face. With a big chalk board.
Hey touring919, thanks for taking the time to draw that on my and others' behalf. I appreciate it. I don't want to belabor this thread, believe me. I do get some parts of the logic. I'd like to hear Bridgestone explain why the the BT-023 front tread faces the same direction as the rear. Some bike tires have tread in the same direction and others have it in the opposite. Pirelli Angel STs, for example, look more like my PR2s pictured. That's what doesn't compute in my feeble mind. If there were some generally accepted or proven priniciple of physics, or whatever at play here, then I would expect more tires to look alike. I get that slicks make for better traction in the dry and grooves channel water in the wet. Forget about DOT requirements (to cover wet and dry). And forget about other specialty tires, like say, off road tires.
Why do some bike tire manufacturers (of street bike tires) choose to "reverse" the tread while some don't? That was the original question and it unfortunately remains unanswered. Is it possible that Michelin and Pirelli have done more R&D and have data that suggests it really is better to reverse the treads? And Bridgestone is behind the curve? Will this thread help Bridgestone catch up LOL? If their next tire comes out with reversed treads they are gonna owe me!
Actually I probably shouldn't knock Bridgestone. As I look at their motorcycle tire website, I see that some of their tires (like the BT-016) do appear to have the front and rear treads reversed. Oh well
Actually I probably shouldn't knock Bridgestone. As I look at their motorcycle tire website, I see that some of their tires (like the BT-016) do appear to have the front and rear treads reversed. Oh well
its very well possible that they did research on some tires and not others depending on marketing/application. its also possible that some tire makers dont do any research. to directly answer your question, the only way for us to find out is ask several different tire companies why they do/don't have reversed tread because at this point we can only speculate since we dont know. what we say we think we know is the approach used for the PR2's and similar tires made by the same company since we got a "legit" response from the tire maker and that's all we have to go on at the moment. the logic makes sense and it actually works in real life.
so i dont know and i dont pretend to know. i think your speculation as to why some dont is pretty spot on.
My dad SWEARS by Metzler's.
Like, if he knew I was getting a different tire, he would be ashamed of me.
I don't get it.
Does he know that Pirelli and Metzeler are the same company? Many of their tires share the same compounds and carcass design differing only in tread pattern.
What I stated is the reasoning for why a front tire would have a "reversed" tread.
As for why a company would use a forward pattern...... That would be speculation on my part. Could be for better water evacuation. Or just because it looks right to the buyer. And their are 100s of other ORs to add to those two.
But the only people that really know specifically why a specific design was used on a specific tire are not going to talk about it here. If you meet one you might get luckly and they will spill the traid secret beans. Or at least the beans the other companies know about but us general enthusiast are still unaware of.
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