| Author | Message | ||
     M1combat |
I am considering which tires to buy next for my XB12R. I don't think I want to go with stock... After reading "Twist of the Wrist" this weekend I am thinking that maybe I shouldn't get the Sportec M1's that I had planned on. Keith says that if you aren't comfortable with getting to the limit of adhesion on state of the art tires, maybe try some that will slip easier so that you can get the feel for it. I assume he would then have you go to the state of the art once you get comfortable with the sliding itself. Any recomendations of tyres that will have good characteristics for turn in and drive but a lower limit with a predictable slide? I will be using these as my daily driver tyres and for track use. As soon as I wear them out, I'll be going to the Sportec M1. (Maybe I'll just go for the sportec's first??) | ||
| Racerx1 |
Comfortable with sliding? I'd say buy the stickiest track tires you can, and with all your extra money you saved from not having to buy bodywork/frames/wheels/ambulance rides due to overheated street tires on a race track, buy a Honda XR100, mount a buell blast rear tire, and head for the nearest dirt lot for the time of your life. If its good enough for Kenny Roberts... | ||
| Frankenstein |
I just put on M1's on my XB12 and just the fact that handling has improved significantely it was worth the switch. No standup on trail breaking, very fast into the turns - that's how the whole bike should have come stock. | ||
| Blake |
For dual street and track the new Pirelli Diablos are rated well. I agree with RacerX1 though. Street tires on the track are asking for trouble once you really start to push things. There just is no comparison between the two. Like night and day. | ||
| M1combat |
I'm not asking for recommendations for good street tires... I'm asking for recommendations for good "track use" tires that have a lower limit WITH a broad useable slip angle so I can learn how to slide on pavement. I grew up on dirtbikes (I reckon I literally gained about 6-8" of my overall height at least ON a dirtbike), I can slide. I want to learn how to transfer that knowledge to pavement. I'm not comfortable with taking a set of top shelf tires to a racetrack and trying to find their limits. From what I know of cars and their race tires, I would imagine that the race tires on a bike are similar in the fact that the "edge" is probably pretty sharp. I don't want a sharp edge. I want something that when approaching the edge will give me plenty of warning (no matter where that edge is...) and be able to maintain traction to a greater slip angle. If the overall level of grip isn't quite as high... Fine. just as long as the slides are predictable and they don't drop me to the pavement as soon as I've gone 2 degrees past their optimal slip angle (Which, as I understand, top tier race tires will do as they are designed to... operate at a fairly specific slip angle and, of course, will operate at a higher LIMIT). I'm not concerned with speed yet. If I can take a corner on a race tire at 80 and be safe to 82 that's great, but if I can get a tire on which I can take that same corner at 70 but be safe to 75 because it has a more broad slip angle I consider that tire better for learning how to slide properly. Basically, if it's like a race car (and I imagine it is, if I'm wrong please correct me) then a race tire will have a higher limit but a MUCH more narrow margin for error near that limit. I would like to have a larger margin for error. I don't necessarily want a "street" tire, but a good predictable tire. Maybe a harder compound race tire as they generally tend to be a little more forgiving. Any suggestions? | ||
| Shazam |
For the XB A great track tire, that I have found to be VERY predictable with regards to sliding, has been The Michelin Pilot Sports. They have more of an ellipse to their cross section which translates to a sharper(more abrupt) feel in your transitions but offer a lot more of a contact patch at steeper lean angles. I think what you are looking for is something that goes from traction to slide smoothly so once you realize it has let loose, (you'll feel it in the bars regardless which end it is) you can get back on it without fear of monumentally abrupt changes to your suspension or direction. The H2's are the track version, same profile different compound and as much as I love these tires(H2's) on the track (I think DaveS will concur) they are absolute shit on the street. Try the regular Pilot Sports, This statement:" will be using these as my daily driver tyres and for track use." rules out the H2's I am by no means an expert, just relaying my experiences......YMMV | ||
| Blake |
Dunlops are noted for their more forgiving behavior in a slide scenario. Suggest you learn to negotiate the track to within 8 seconds of the outright lap record before you even think about backing the thing in or spinning it up coming out of corners. For 99% of us, sliding on a road bike means crashing on a road bike. | ||
| Wyckedflesh |
If I could get within 8 seconds of the outright lap record I would be a VERY happy camper Blake. I haven't come that close to a track record since I stopped racing all the time. | ||
| Blake |
See my first reply.
Can you see my confusion? The tires don't provide the margin, the rider does. You need to decide whether you want track tires that are made for racing, or street tires that can survive a short stint on the track every now and again. You don't want to run track tires on the street. Street tires are a compromise on the track. Learn how to go fast, then and only then start to think about how to go faster. Chances are that even with street tires, stuff will be dragging well before you reach the limits of tire adhesion. | ||
| Austinrider |
I'm gonna chime in here. I use Metzler Sportech M1's on my XB9. I take my bike to the track and ride on those same tires on the street. I have not had a problem with lean angles or sliding (except for when Im scrubbing off the edges of the tires on the track and they slip a bit and catch again). The tires hold up great. Im probably about an inch from dragging a knee still. I dont think my tires will have any problems with slipping when that time comes. Are you saying you want a tire that you can ride on the road and also the track, a tire that will give you the maximum lean angle on the track and still be usable on the road. Maybe I just dont understand the question. edited by Austinrider on January 07, 2004 | ||
| Shazam |
At no time during my exposure on the track have I intended to slide the tires.....My post was not intended to help you find a tire that will slide just that when it has happened to me it has been a non-event (I take that to mean forgiving......) a hair raising scary as shit non-event. Blake there is a lot of subjectivity in that 8 second statement..... | ||
| M1combat |
From what I have learned about car racing, the tires are the MAIN bottleneck given reasonably equivalent drivers. I can only relate this with four wheels but I am hoping that some of you here (probably most of you here) that have more experience on two wheels will see the correlation. When you reach the point at which a tire passes it OPTIMAL slip angle it is also generating it's greatest amount of grip. The moment you cross that line, not only are you exerting MORE force on the tire, but you also begin to have less and less traction. This becomes a bad situation quite quickly (It's even worse if you have wings as the distance from the leading to the trailing edge of the wing increases, thereby lowering the effective AOA of the wing). Things go very wrong VERY quickly. The more grip you HAVE to begin with, the quicker you LOSE traction on the other side of the envelope. Going over the edge of the envelope is OK, but only if you are comfortable and familiar with what to DO (Re-distribute weight). If you are not (ME, on a motorcycle) then you better hope that your tires have a very broad usable slip angle because you can explore the SAFE edge of the slip angle and be confident in the fact there is quite a bit (compared to a race tire) of usable slip angle left before the tire gives you the finger. Yes, the tire will indeed give you the finger at a lower speed than the race tire, but it will accept a greater range of slip before it does. Because I don't KNOW how to slide, when it happens I'll be reacting for the most part, and using a good deal of my concentration. Once I get it figured out, I'm perfectly down with grabbing an extra set of tires and wheels and mounting qualifying rubber and seeing just how much rubber I can lay down in one drift (Knowing that optimal slip angle is best, and drift is just fun). Here's another way to put it... The tires I am looking for are a bonfire. Slick race tires are a LIT MATCH. You can be 10' away from a bonfire and feel the heat. You need to be close to a match to feel the heat. In which case are you about to be burned? Especially when the flame of the match is a good deal warmer (read more lateral G's) than the bonfire... Anyway, if that made any sense... Well, we probably both need to concentrate on lucidity  . The thing is, I have experience with Metzler Perfect's on my Honda (Which is old and I need to rebuild the forks so I never really tried to push it) and the stock tires that came on my 12R. A tire like a Sportec M1 or a Pilot Sport may just be exactly what I'm looking for, but that would mean that I am trying to explore the limit on a "treaded race tire". That doesn't seem to ME to be the best way to learn to slide. After all this, keep in mind that I tend to go absolutely NOWHERE near the limit on streets. Mostly because around here there are large drop-offs and ROCKS everywhere... Excellent roads though... | ||
| Wyckedflesh |
Car tires and motorcycle tires are 2 VERY different animals. That is like comparing apples to oranges they are both fruit just like tires are made of rubber but from there things go very wonky. As to the Pilots there are different levels of the Pilots based on compound. The street version is what is being recommended which is a STREET tire that can take OCCASIONAL track use not the other way round. | ||
| M1combat |
Hmmm, I suppose I see you point about the tires themselves being very different but... You still have a contact patch, wear characteristics, Grip levels modified by pressure and temp, patch deformation, those wiggly little lines that tell you how much slip you are using (hint hint), and forces applied to the tire patch. I undersatand that the tires AND how they WORK are quite different, but the song remains the same. They are used to attach you to the road. I am interested in being attached to the road with certain capabilities. The mechanics of exactly HOW these thigs happen is unimportant. The fact that they happen is what is important. Some race car tires offer less overall grip, but are very predictable in their handeling characteristics. Other race car tires offer more grip, but the edge of the envelope is very sharp (most good drivers prefer these, but it also depends on the track, I would think you would want a very forgiving tire for The Ring and a very sharp tire for Monza). This must be the case with bike tires as well. I need one that offers less overall grip, but a large arc of usable slip angle. It would indeed be a "street" tire as I'm not interested in wearing them out in 300 miles. My issue with a top shelf superbike "street" tire is that the limit will be so high that I really can't hope to approach them for a long time myself... I'm not that good. So, if I can get a tire that will be suited to my capabilities I can learn more in less time. | ||
| Blake |
"OPTIMAL slip angle"  That's a new term for me in the world of moto road racing. You are overanalyzing. Learn to ride on the track first. You don't want to slip on asphalt. Your "treaded race tire"s are not racing tires unless specifically so designated... such as "Michelin Pilot Race M2". The tires that come on the bikes are street tires, not track tires. Racing tires also have tread, not near as much as street tires, but they do meet DOT requirments. There is little difference in the performance of racing DOT and racing slicks. I would think that the tire that provides the best grip but still meets your requirment for street use would be the best choice. That way you don't need to worry about slip. That said, Dunlop racing tires seem to allow sliding in a more forgiving manner than other brands. Ben Bostrom liked that quality about them. I have no idea about the performance of street tires. Basically, if you are leaned over hard apexing a turn and one of your tires lets go, you are going down. There is little to no room for error there. If you are coming in hot on the brake and the rear tire breaks loose, you can easily feel that and adjust and keep right on going; same goes for breaking the rear loose or "spinning it up" upon exiting a turn. That can be recognized and ridden out or corrected. What you are asking for though does not exist. What you are asking for depends more on the chassis and rider than the tire. Most any top quality name brand track capable tire will work. The rest is up to you. I'm no expert, but I've put over 1,000 miles lapping a track and have reached the point of lost traction on a few occassions. I try to avoid that. I've still 12 seconds off the track record. I have friends who are 5 seconds off the record who don't slide their bike around. They of course are running racing compound tires. Just ride. | ||
| M1combat |
Hmm, Maybe then, the Dunlop's are the way to go. Have you read Twist of the Wrist? Sliding is a tool that can be used to your advantage. As far as slip angle goes, I assure you, ANY time you are not traveling in a straight line, you are inducing a slip angle. Every tire has an "optimal" slip angle that is defined by where the tire makes it's greatest amount of grip. It's not exactly "sliding" yet, but slipping. It's because the tire is reasonably undeformed when the rubber lays down, then THAT section of rubber travels to the rear of the tire patch, it is now in a different place than it used to be when compared to the section that is now being laid down. This is caused by the fact that the tire is working to accelerate the bike. It's called deformation. When sitting still, turn your forks left and right and pay close attention to the contact patch and sidewall (maybe have someone else do the turning?). The tirepatch will deform. The tirepatch does almost EXACTLY the same thing when you are moving, except that the deformation starts at the front and only moves one way as opposed to the center staying where it is and the edges being pulled upon. ALL tires are designed to perform at an optimal slip angle (not slide angle, slide is after slip. Slip is in between grip and slide, slip is GREATER than slide AND grip). Race tires operate at a greater maximum level of grip, but generally have a much more narrow range of that sweet slip angle. Street tires have less grip, but are capable of operating "well" over a larger range of slip angle. As far as your last paragraph, "lost traction" is after slip. This is why I want a wide range of usable slip angle so I can feel it when I get near it, and have say six to eight degrees left before the tires actually give up. On a race tire I will feel it, and because I am not familiar with it, I will exceed the usable slip angle before I figure out what to do and... well... I guess there's always the NEXT track day... well, maybe... In any case, I figure if Keith Code recommends doing this, it's probably not a bad thing. I will slide a bike someday. I would rather use a tire that is "easy" to slide to learn HOW to slide than just accidentally slide one day on a tire that takes a good deal of skill to slide properly and lose everything. | ||
| M1combat |
As far as worrying about slip (I think you mean slide though)... If I don't worry about slip at all, when it happens is exactly when I WILL worry about it. That also happens to be the exact time in which I REALLY don't want to worry about it. I don't like surprises at speed, they tend to cause wrecks. | ||
| Blake |
Then get the tire that grips the best. I don't see how having a tire that won't grip as well but will slip over a wider range is any advantage. It will not help you survive or go faster, especially if you ever plan on using actual racing tires. Motorcycle street tires won't last any longer on a track than medium or hard compound racing tires. If you are so serious about learning to push your bike on the track (cause that IS what you are talking about), you really need purpose built racing tires; it's that simple. Yes, I've read Mr. Code's book. I paraphrased him in my advice to you. Learn to go fast before worrying about stuff like sliding the bike. That is about last on the list of things to learn to help improve your lap times. Before that you want to learn... 1. braking points 2. shift zones 3. turn-in points 4. exit markers 5. smooth transitions from on-throttle to braking and vice-versa 6. staying smooth while trail braking and downshifting 7. optimum tire pressures and suspension setup Once you are expert in all the above, then and only then, should you think about sliding the bike around on purpose. You avoid surprises at speed by not pushing your envelope too much. Has nothing to do with the slip angle of the tire. It is self control and patience. Interesting commentary on the "slip angle". I'd not heard that discussed before. Again, the Dunlop D207GP racing tires had a reputation for providing a more controlled/intuitive slide than their competitors. Not the street tires, the race tires. | ||
| M1combat |
Alright, I see your point. Learn to go fast with what I have and at that point approaching the limit won't seem like such a daunting task because I will be comfortable with the speed. I suppose it's not the speed that "may" bother me but the lack of a cage. I guess I just don't feel quite as immortal as I did 10-15 years ago... I'm not too worried about falling either. One thing Jiu-Jitsu has taught me is how to do that, and as an added bonus I have a whole room full of Tatami mats that I can use to practice the "relax on command" theory. At any rate though, I am at least wise enough to know that from experience filtered by intelligence comes knowledge and wisdom so I'll take your word for it. I'll do some research into which top shelf sport bike tires produce predictable/intuitive slides and get those. Unless of course they are also known to do wierd stuff to an XB frame... If you want more information on contact patch deformation try www.corner-carvers.com. They are basically the "Badweb" of car suspension and most of them seem to like Mustangs and Camaros (with MANY suspension mods though) with a lot of M3, Supra, Datsun 510's and that sort of thing. They have a good deal of info on tire patches and such. I understand that car tires aren't motorcycle tires, but I would imagine there's not a WHOLE lot of difference. It's all about flat contact patches made of rubber on a wheel that's attempting to cause acceleration. I'm sure there are a few key differences, but I can't find much info on the physics of motorcycle tires... From what I've learned about car suspension though (from Corner Carvers), I can look at the XB suspension and see a FEW reasons for doing what they did. Most of it's still Voo-Doo to me though. I've been thinking of picking up a copy of both "Twist of the Wrist 2" and "The Soft Physics of Motorcycle Dynamics" this week for some light reading this weekend. Do you have any other recommendations for learning the physics of motorcycle suspension? I have read Marcus McBain's website also. edited by m1combat on January 07, 2004 | ||
| Jazzman |
I have been riding for a long time & blake you nailed the throttle full bore.If you don't know the machine you won't be able to even push it to its safe limits. | ||
| Apex1 |
M1, I believe that most of the "super-sport" tires (D208, M-1, BT-020, Pilot Sports, etc) out there will satisfy what you're looking for. They are designed to offer plenty of grip (although not as much as a race compound or slick), over a wide operating range of temperatures & lean angles. The result is a tire that will offer you plenty of what you're calling slip (not slide) with a decent margin of safety. Check out different the manufacturer's tire profiles: Dunlop D208ZR's seem to be a little flatter than some of the others. Hope this helps. | ||
| Blake |
Do you have any other recommendations for learning the physics of motorcycle suspension? Lots of time at the track, make and review detailed notes. Collin Edwards isn't fast because he studies the theory behind motorcycle suspension behavior, he's fast because he lives it. | ||
| M1combat |
Jazzman - If you learn the feel of "the limit" itself though, one could then apply that knowledge while using a more capable tire. It's my understanding that a tire that's capable of a good deal more overall grip compared to another should always offer a sharper edge than the less capable tire. I'll probably only truly know on my second set of race tires though. Apex - I'll take a look at the profiles and study some suspension physics. Blake - Will do, but not for a few more months . I'll bet you Collin Edwards HAS studied suspension theory though. | ||
| Evaddave |
M1, I have 0 track experience, so I might be way off-base here, but I had a couple thoughts to throw your way. Motorcycle tires have a different shape than car tires (duh). That difference means that as you lean the bike into the turn, the contact patch is "moving" with respect to the centerline of the tire. (i.e. in a left turn, the contact patch is more on the left side of the tire than on the right. When riding straight, the contact patch would be equally on both sides of the tire's centerline.) In a car, the contact patch is the contact patch, whether going straight or turning. At some point in a car, though, you will turn hard enough to deform the sidewall, and that will change the contact patch--typically making it smaller by lifting the inside edge. With a smaller contact patch, you'll have less grip, etc. I don't know how cycle tires deform at the limit of grip, but since the tires have a rounded profile, they wouldn't exhibit the sidewall deformation to the extent that the car tires would. Ok, enough on that. My other thought was that instead of getting tires with degraded performance, why not practice on a surface with degraded performance? You said you already knew how to slide on dirt; why not try gravel? Or wet pavement? (this is the Bad Weather Bikers' board, no?) Hey, it's winter. Maybe find some ice. My point is that you can go slower, and therefore you should have more reaction time. As you "get the feel" for it, you can then move up to faster speeds. | ||
| M1combat |
Well, I rode a lot of dirt bikes, and I grew up in Alaska so I have a good deal of experience on ice (w/o studs mind you). The problem I see with a degraded surface is that I couldn't make it consistent. Understood on the possible cause of less deformation, and I think another factor would be the much smaller mass of the motorcycle. Enabled through the elasticity and construction of the tire the manufacturers would still want to operate at a slip angle because you can get energy back due to the rubber's elasticity. | ||
| Mikej |
"Coos Bay, Oregon" Neat. Been there a few times visiting relatives and friends of relatives. Welcome aboard Jazzman.  MikeJ (Former Oregonian, now transplanted a few times.) | ||
| S320002 |
Dunlop tires have been the choice of "sliders" for several years. They are known for less abrupt transition into a slide and more control during a slide. Does that answer your question? | ||
| M1combat |
Pretty much S3... I'll look into them. | ||
| Blake |
Clarification... The racing tires, not the street tires. | ||
| M1combat |
Sooo, which street tires are known for producing controlled slides and having a high level of grip? | ||
| Mikej |
Probably depends a lot on your specific road surface conditions. Tire use in race settings can vary depending on the track, the weather, the bike setup, and the rider. Consider in this case that the ruler used to define the best choice is made of elastic. I like my Dunlops, but may switch to Metzlers or Bridgestones next. But then I'm not planning any track sessions. | ||
| Henrik |
There was a couple of interesting articles in Motorcycle Consumer News by Tony Foale recently. They went into detail about bike geometry, feel etc. Among other things graphed how MC tire traction acts around the limits. Well worth the read. Also had some insight into how the bike will feel just before it lets go - not that I have any illusions that I'd notice. But still nice to know  Henrik | ||
| M1combat |
I am assuming that's a magazine??? I'll do a search though. | ||
| Wyckedflesh |
http://www.motorcyclenews.com/advice/detail?sectionID=52687&documentID=6302&navI D=441 MCN tyre article...(UK MAGAZINE) http://www.mcnews.com/mcnews/ Afore mentioned Motorcycle Consumer News | ||
| S320002 |
Blake, I read a couple of articles sometime ago, I forget where, that claim the Dunlop sport bike street tires share many "sliding" characteristics of their racing cousins. |
