Used Tires?

[raysigh]

 

So I'm a track novice in B group, and was surprised at how quickly S22's get to the edge of the tire. I've been told that I can lean past the edge of the tire so I had more lean angle to go. However, I do really want to try Q4's as I was told by pretty much everyone at the track that that's what I want.

Is it a really bad idea to slap on a set of these used Q4's? They're $30 a set front/rear... I think the rears are at or damn near the wear bars..

Edited November 30, 2020 by raysigh

[scat2me]

Is it worth the risk?

[mossrider]

Spring for a new set first. This way you can make an accurate, informed decision about Q4's based on new tires and with peace of mind. If it turns out you like them (not everyone does) then look at take offs from a reputable source. There's  a big difference between good 'take offs' and 'used tires' too.  Low lap take offs from a racer that runs 10-20 laps then springs for new rubber out of pocket, through sponsorship or from tire certs is a great source for cheap, good rubber. Tires that have been replaced at or past the wear bars by a racer/track day guy because he's cheap or getting nervous about them is a no-go. 

Those tires in your pic don't look too bad for reference but they are getting to end of their life. Sometimes you can get lucky and get them for nothing directly from the source but $30 is cheaper than $300 I get it. Just do yourself a favor and try a new set first to help you make an informed decision. Bridgestone S22's are a fine tire as are many other models from all of the common track tire companies, you really should try them all. And it won't hurt you a bit to get more experience before delving into more advanced arena's like this. Have safe fun.

$.02

Blue Line Racing

 

[M. Hausknecht]

I agree with Mossrider. Moreover, keep in mind that track-used tires can be "worn out" for track purposes even with plenty of rubber remaining. This is so because flat bands can be worn into tires from an oft-used lean angle. Put your palm on the tire, is the profile flattened at any point?  If so, the tire will have "suddenly" less grip when leaned over further than the band.

Edited November 30, 2020 by M. Hausknecht

[klx678]

Isn't it more about the heat cycles with track use?   Even if they look good they may be "worn out" when the rubber compound is considered.  Or is that just a myth?

[raysigh]

28 minutes ago, klx678 said:

Isn't it more about the heat cycles with track use?   Even if they look good they may be "worn out" when the rubber compound is considered.  Or is that just a myth?

This is also what I thought.

[raysigh]

The main reason I want to switch to the Q4's is because of tire profile. After the first session on the S22's I was at the edge 

This was at lean angles less than what I was at on the road before on Michelin Pilot Road 4's and Dunlop Roadsmart 3's. After seeing that the entire rest of the day I was scared to lean it over more - even though, I've been told that I can lean beyond this point? 

[mossrider]

Just now, klx678 said:

Isn't it more about the heat cycles with track use?   Even if they look good they may be "worn out" when the rubber compound is considered.  Or is that just a myth?

Here's the mini course in tires.

'Heat Cycles' are basically a thing of the past for modern tires. Technology has made heat cycling a non issue in the past 5-10 years and even that is changing as the manufacturers roll out even newer tech track day tires that require no warmers.

Once upon a time there were racing slicks. And there were D.O.T. or Street tires. They were both raced, albeit in different classes, usually in Supersport (street bike class) and Superbike/GP (race bike). Race tires required electric warmers to use safely as they needed to be pre-warmed to a higher operating temperature to function as designed where they offer higher performance benefits than D.O.T. tires. D.O.T. tires were exciting but sucked to race on. Warming D.O.T. tires did nothing but hasten their demise as they were designed to operate for great lengths of time at much lower temeratures than race tires. Overheat a street tire and it got greasy and would put you on your head. In exchange for lasting forever they could not offer the traction or handling of race tires. Racers would switch back and forth between slicks and D.O.T. street tires to race their bikes in different classes, sometimes swapping exhaust, airboxes, carb banks, and even cams at the same time. Sometimes SS races were Saturday. The swap took place that night and Superbike and GP races were Sunday for convenience. 

Then came the next generation of D.O.T. race tires, treaded tires that offered the performance of race tires. They needed to be heated with warmers lest you end up on your head. They utilized higher heat and offered near race slick levels of performance. But they wore out quickly compared to true D.O.T. street tires. We still swapped tires to race different classes but true GP bikes like the TZ and RS were disappearing about then too. Racing was changing again. About this time the modern Supersport bike as we know them today was becoming popular. Motorcycles were becoming too fast and powerful to race on street tires. We no longer raced on street tires except for the ocaassional damp track or endurance race where we thought the extended life or better siping offered an edge. The difference between Race Slicks and D.O.T. tires were almost nonexistent now. They both operated near 200 degrees and could lean to the moon.

Enter the modern 'hypersport' tires. Q3, Q4, S22, RS11, blah blah there are many others by all manufacturers. They self heat to operating temp with a trip around the paddock and offer really impressive traction, handling and wear. (Some folks will heat them for a few minutes but you have to be careful not to overheat them) Heat cycles mean nothing to these tires as they are designed to be abused and neglected under almost any condition (short of overheating) for many miles. 

Now cometh the Honda Grom et al and motorcycling as we knew it ceased to exist, lol. 

Anyway theres an over simplified time line/explanation of tires and heat cycles. I hope it helps.

$.02

Blue Line Racing 

 

[mossrider]

Just now, raysigh said:

The main reason I want to switch to the Q4's is because of tire profile. After the first session on the S22's I was at the edge 

This was at lean angles less than what I was at on the road before on Michelin Pilot Road 4's and Dunlop Roadsmart 3's. After seeing that the entire rest of the day I was scared to lean it over more - even though, I've been told that I can lean beyond this point? 

You're a good ways from maxing that tire sparky. My last supersport race (on DOT tires) I got beat by a guy running S22's. I was running Pirelli Super Corsa SC2's. No way I could lose right? Dead lock on that trophy. I demand a re-count, I was robbed, it was a l....never mind. 

That tire is wearing great. 

[raysigh]

33 minutes ago, mossrider said:

You're a good ways from maxing that tire sparky. My last supersport race (on DOT tires) I got beat by a guy running S22's. I was running Pirelli Super Corsa SC2's. No way I could lose right? Dead lock on that trophy. I demand a re-count, I was robbed, it was a l....never mind. 

That tire is wearing great. 

I have a theory about why I have a ways to go in terms of lean angle... Is it that once I get beyond the edge, yes my contact patch begins to shrink (also could depend on level of sidewall deformation). However, the amount of grip even with a smaller contact patch is not sufficient to begin slipping until far beyond that edge? There has to be a point where yes, the tire profile (which I've compared to my Dunlop Roadsmart 3's), will eventually shrink my contact patch to the point of slipping. 

Also, rear tires are wider than front tires because a larger contact patch is needed to handle the power. By this theory... then a 180 tire should provide excess grip from it's larger contact patch until no throttle, no brake, leaned over condition no? SO again, theory in my head says, even if I'm off the edge of the tire, I still have a ways OFF the edge of the tire before the rear lets go, and even then, it might be the front that lets go first from lateral forces anyways?

Either way, I should be feeling for grip by progressively taking the same corner faster/with more lean angle until I begin to feel slip. With a tire as solid as an S22, if I'm progressively increasing speed/lean angle, the slip should also begin progressively and with ample warning. I'm scared to crash again, as you well know mossrider. I went down first lap first corner on that brand new, cold S22. It was horrible.

Edited December 1, 2020 by raysigh

[raysigh]

 

39 minutes ago, mossrider said:

That tire is wearing great. 

You mean not overheating or cold tearing? I did actually borrow a temp gun for fun and got some temps in addition to pressures. 

Surface temps were about 120+/-2 front and 130+/-2 rear (center band) hot off the track.
Cold pressures put in were 30 front / 28 rear
Hot pressures were about 35+/- 0.5 front / 34+/-0.5 rear 

[mossrider]

Just now, raysigh said:

 

You mean not overheating or cold tearing? I did actually borrow a temp gun for fun and got some temps in addition to pressures. 

Surface temps were about 120+/-2 front and 130+/-2 rear (center band) hot off the track.
Cold pressures put in were 30 front / 28 rear
Hot pressures were about 35+/- 0.5 front / 34+/-0.5 rear 

I mean neither. And an infrared temp gun surface temperature means nothing. We need the carcass temperature data and we can only get it from a pyrometer using a probe and checked at least 3 times across the width of the tire. I've compared both types of temps back to back many times to see if there is some correlation and there is but only after taking a thousand readings in a thousand differing conditions to develop a database and gain experience. I'd get 115 degrees infra, and as much as 190 degrees probed on longer pit returns. And 150 infra, 160 carcass on hot pit shorties. The surface of a tire can cool quickly spinning freely unloaded back to the pit whereas the carcass will hold heat much longer. Getting the tire into its operating range and keeping it there is what maximizes it's performance. A pyrometer is the only sure way to know. Otherwise you may well be dealing with hot and cold tear and other issues at some point. Get yourself a good tire pressure gauge and a pyrometer if you're going to spend any amount of time on track, you'll be glad you did and your friends will soon think you're the bomb. 

That trash you see on your tire is picked up off the track by the warm tire coming off track and back to your pit. You can pick those off the tire surface with your fingernail. You may have to pick a bit and dig at them because they really stick but they'll all come off. Those are neither cold nor hot tear, just gunk.  True hot or cold tear is actual micro damage to the tire and cannot simply be picked off the tires surface as it may appear. You will be able to grab them with your finger nail much like gunk but they will not 'come off' so to speak. Picking at those will reveal shallow, moon shaped cuts or tears beneath what appears to be loose rubber which is actually still attached to the tire on one side.  

That S22 will operate nicely at carcass temps you are recording but it is not a full race tire so you have to be careful about applying race tire standards to it. That tire would never stand up to the carcass heat (200 degrees) a race tire is designed to operate at.  At the same time a race tire would never last the 2-3000 miles that S22 would either. Hot and/or cold tear is manifested more subtlety. An S22/Q4/street tire is more durable than race tires which are actually quite fragile compared to street tires. It's more a question of it works or it doesn't. 

Having done tires for this long I typically feel the inside surface of the rim when the tire is on the warmers to check temp. If the wheel is warm, the carcass is too.  To warm up D.O.T. tires I take the long way to the track entrance then a warm up lap at track days (75% outlap to grid when racing) before hammering on it.  

[mossrider]

Just now, raysigh said:

Also, rear tires are wider than front tires because a larger contact patch is needed to handle the power. By this theory... then a 180 tire should provide excess grip from it's larger contact patch until no throttle, no brake, leaned over condition no? SO again, theory in my head says, even if I'm off the edge of the tire, I still have a ways OFF the edge of the tire before the rear lets go, and even then, it might be the front that lets go first from lateral forces anyways?

Either way, I should be feeling for grip by progressively taking the same corner faster/with more lean angle until I begin to feel slip. With a tire as solid as an S22, if I'm progressively increasing speed/lean angle, the slip should also begin progressively and with ample warning. I'm scared to crash again, as you well know mossrider. I went down first lap first corner on that brand new, cold S22. It was horrible.

Rear tire width on modern motorcycles is more a design feature than anything. Just look at Moto3 bikes. About the same hp as a stock fz, less than half the weight and the quickest corner times of ANY motorcycle, including Moto2 and MotoGP bikes even on those skinny bicycle tires. 

You are correct on the sliding tires. At some point as corner speed rises you will begin to run out of traction. Peak corner speed is an absolute finite number. At some point nothing can defeat the laws of physics and the motorcycle will go down. As you approach this velocity you begin to learn 'feel' (or crash if you don't).  Good track tires spread out the threshold of traction loss and give that slide warning as they approach total loss of traction. The key to learning feel is to enter that zone on purpose and not by accident. By this I mean with digital line and bike handling and with absolute repeatable control so you have adequate time to recognize it and react to it so you can learn to manage the onset of the slip (depending on whether it's front or rear tire) and make small, appropriate control inputs to correct for it and finish the turn at speed. As opposed to botching an entry and trying a hail marry that either works or does not and hence you learn nothing from the incident other than crash repair or underwear recovery. 

I have found that some tires slide early and easy and offer a wide warning band yet still to let go suddenly when they do go. Other tires don't begin to slide until much closer to traction loss, offering a narrower band of warning but are very predictable and offer controlled traction and a predictable let go. It's kind of a personal preference thing that has to do with riding style, bike set up, desired handling goals etc. That's why I suggested earlier that you should try several tires. 

 We could go on for ever, sorry for the encyclopedia. 

[raysigh]

8 minutes ago, mossrider said:

Rear tire width on modern motorcycles is more a design feature than anything. Just look at Moto3 bikes. About the same hp as a stock fz, less than half the weight and the quickest corner times of ANY motorcycle, including Moto2 and MotoGP bikes even on those skinny bicycle tires. 

You are correct on the sliding tires. At some point as corner speed rises you will begin to run out of traction. Peak corner speed is an absolute finite number. At some point nothing can defeat the laws of physics and the motorcycle will go down. As you approach this velocity you begin to learn 'feel' (or crash if you don't).  Good track tires spread out the threshold of traction loss and give that slide warning as they approach total loss of traction. The key to learning feel is to enter that zone on purpose and not by accident. By this I mean with digital line and bike handling and with absolute repeatable control so you have adequate time to recognize it and react to it so you can learn to manage the onset of the slip (depending on whether it's front or rear tire) and make small, appropriate control inputs to correct for it and finish the turn at speed. As opposed to botching an entry and trying a hail marry that either works or does not and hence you learn nothing from the incident other than crash repair or underwear recovery. 

I have found that some tires slide early and easy and offer a wide warning band yet still to let go suddenly when they do go. Other tires don't begin to slide until much closer to traction loss, offering a narrower band of warning but are very predictable and offer controlled traction and a predictable let go. It's kind of a personal preference thing that has to do with riding style, bike set up, desired handling goals etc. That's why I suggested earlier that you should try several tires. 

 We could go on for ever, sorry for the encyclopedia. 

Ah yes. Our 180 tire is def not for the amount of power we have haha.

Is my assumption of contact patch beyond the edge of the tire correct or should I not even be thinking about it in that way. I'm just so stuck on judging the limit by something I can SEE vs feel right now - which I  realize isn't how it should be judged. 

[stickshift]

10 hours ago, raysigh said:

The main reason I want to switch to the Q4's is because of tire profile. After the first session on the S22's I was at the edge 

 

This was at lean angles less than what I was at on the road before on Michelin Pilot Road 4's and Dunlop Roadsmart 3's. After seeing that the entire rest of the day I was scared to lean it over more - even though, I've been told that I can lean beyond this point? 

Do you have the standard rear sets fitted? I do, and with the S22s I can’t lean past the edge of the rear tyre without seriously grinding out the standard foot pegs (feelers removed from them).

I notice that you have a stock rear shock. Depending on your weight it might be lowering the rear of the bike too much also, reducing your cornering angle.

Small point, but Bridgestone recommends 30/26 psi cold front/rear for S22 on track, has worked well for me:

https://www.bridgestonemotorcycletires.com/content/dam/motorcycle-tires/files/Track-Day-Air-Pressure-Chart-May-2020-FINAL.pdf

Edited December 1, 2020 by stickshift

[raysigh]

2 hours ago, stickshift said:

Do you have the standard rear sets fitted? I do, and with the S22s I can’t lean past the edge of the rear tyre without seriously grinding out the standard foot pegs (feelers removed from them).

I've got rearsets on there. I think the next grind point after that would be the sidestand extension.

I meant to try out 26 rear, but the tires never fully cooled down the entire day after the first session. Next time I'll give it a shot. 

[klx678]

On the topic of tire size, is there any good reason to not drop from the 180 to a 170 or even a 160 if suitable for the 5.5 rim for garden variety street riding?    This is on an XSR, not the FZ or MT.   

One reason for the consideration is spreading the tire a bit puts a bit more rubber on the road width wise, second reason is the price is lower.  After all in general street riding it is the center that wears fast.  I'll never see the edges like you guys do with the track days and racing.   I will just be wearing rear tires out in the middle.    Seems when I dropped from a 120 to a 4.10 dual sport tire on my 250 dual sport the spread of the narrower tire flattened the center a shade, putting more tire on the road and it has worn really well.  Opposite of what some might think.

[mossrider]

1 hour ago, klx678 said:

On the topic of tire size, is there any good reason to not drop from the 180 to a 170 or even a 160 if suitable for the 5.5 rim for garden variety street riding?    This is on an XSR, not the FZ or MT.   

One reason for the consideration is spreading the tire a bit puts a bit more rubber on the road width wise, second reason is the price is lower.  After all in general street riding it is the center that wears fast.  I'll never see the edges like you guys do with the track days and racing.   I will just be wearing rear tires out in the middle.    Seems when I dropped from a 120 to a 4.10 dual sport tire on my 250 dual sport the spread of the narrower tire flattened the center a shade, putting more tire on the road and it has worn really well.  Opposite of what some might think.

Normally one size up or down in tire size is no problem. Go more or and you can run into unexpected issues like ground, chain, swingarm or bodywork clearance or kickstand height issues so you need to be more careful. You also have issues with the 5.5" wheel width and most 160 series tires.

I've run 170, 180/55, 180/60, 190 series on my zed with no problems. 

You could try dual compound rears. But generally you're looking at 2 rears to every front give or take, on track or off.

 

 

[raysigh]

Some S22 photos

So unless the 190/55 (ZX10R) has a different profile than the 180/55, this guy is pretty far off the edge of the tire.

 

I also notice this type of wear pattern with the rubber pushing OFF the edge of the tire. Also indicating leaning beyond the edge?

 

Edited December 1, 2020 by raysigh

[mossrider]

50 minutes ago, raysigh said:

Some S22 photos

So unless the 190/55 (ZX10R) has a different profile than the 180/55, this guy is pretty far off the edge of the tire.

 

I also notice this type of wear pattern with the rubber pushing OFF the edge of the tire. Also indicating leaning beyond the edge?

 

The S22, like other tires, is engineered to meet the design criteria of its intended use. So although it appears to be past the edge of the tire, it is in fact, not. The fact that that rider has his elbow down (granted an admitted promo shot) and has the bike heeled over would suggest the tire works fairly well on track, with room to spare mounted on an FZ07. 

You are correct, the profiles are in fact quite different across tires and manufacturers. You will feel differences in handling, cornering, stopping and acceleration. Again why one should try several to see what they like or what suits their bike, their riding style or their specific set up.

Rubber accumulates at the edge of the tire because the tire does not touch anything there to scrub it off.

[klx678]

4 hours ago, mossrider said:

Normally one size up or down in tire size is no problem. Go more or and you can run into unexpected issues like ground, chain, swingarm or bodywork clearance or kickstand height issues so you need to be more careful. You also have issues with the 5.5" wheel width and most 160 series tires.

I've run 170, 180/55, 180/60, 190 series on my zed with no problems. 

You could try dual compound rears. But generally you're looking at 2 rears to every front give or take, on track or off.

 

 

Thanks for your response and input, I do appreciate it.

I figure I will do the 170 for sure if I can, but I've found some 160s are listed for 5.5 rims, which I would verify before doing one.   The profile on them is higher numerically and in the case of a 170/60 the smaller tire is numerically taller.  Reality may be different.

I'm just not sold on the need for the fattest tire one can stick on a bike.  If I went to spoke rims I'd do a 4.5 or 5 rear rim and run a 140 or 160.    When you're wearing a 2" section in the middle it really doesn't help to have the wide tire.   I also like a bike with quick handling, so the help there is nice too.   I've raised the forks 10mm and will be going 20mm when I do a fork kit.     On my old 550 Zephyr I went to a 110/70 on the front, raised the rear about 2", which took it from "truck" to near as quick as my dual sport was.   Near perfect.    

[fzar]

On 12/1/2020 at 11:36 AM, raysigh said:

So unless the 190/55 (ZX10R) has a different profile than the 180/55, this guy is pretty far off the edge of the tire.

No. Not at all, hanging off the bike pretty well, but a long way from exceeding the tyre profile taking PSI into consideration.