Chicken Strips. What Happens When The Contact Patch Reaches Tires Edge?

[Corey]

I only ride on the street (no track). I am running Bridgestone BT-023's. I have chicken strips. They are rather lean strips, but I kind of like that I have them. They make me feel like I'm not pushing harder than I should.

Here is my question. What exactly happens when the tire to road contact patch moves beyond the edge of the tire? I realize there is a critical point where you will lose traction and it is probably different for every tire (and compound). I am more interested in knowing how worried one needs to be as they approach the edge of the tire and how much you really have to play with once you get there?

[Rush2112]

As you approach the edge of your tire you have about the size of a credit card that is in contact with the road. This is what is maintaining control of you & the bikes mass. At 45 degrees lean angle you are exerting 1G of vertical force and 1G of lateral force on the tire contact patch. At this point most, and as you lean more eventually all, of your tire's grip is being used to corner the bike; very smooth, small inputs whether steering, braking, or gas is all you can ask of the tire. Exceed available grip in the front and you low side, slide the back and it can go either way depending on your response... worse case, you slide the rear & chop the throttle and the tire hooks back up hard and you high side painfully...

For the most part, VFRs with modern tires will out perform most riders... best advice, take rider training classes like Total Control and learn your limits safely. If you are asking this question and you only ride the street and you haven't had training... which it appears you haven't since you're asking the questions... don't push it.

As Kimball said, "If you are riding safely, having fun, and at the end of the ride you are still smiling... then you are riding correctly..." or something like that.

[Corey]

I have been riding on and off for 35 years (more dirt when I was younger, mostly street now). It is one of those things I learned at an early age and have just done for so long. I never had any formal training. I couldn't tell you the function of every part in the motorbike, but I do know how to make it go. I guess I just want to learn more and whenever a question comes to mind I just ask it. Otherwise I tend to forget it.

I know asking such a question makes me appear as an amateur (and my "worried" comment probably didn't help), but I don't mind asking "stupid" questions. It is the only way I learn. I guess I am more interested in understanding the science of it really. And my chicken strips aren't going anywhere.

[trjerm]

I'm getting older, but normally riding on the street I have approx 1/8 " chicken strips (unless riding Icehouse Rd. regularly), but did a track day on my VFR RR @ the start of May @ Sears and they were worn to the edge and bubbly/ sticky and they felt secure ( PP3's). It was a blast, 1st time out on Sears in 39 yrs.

[Earthshake]

To a certain extent, it depends on the tire profile. Some tires I have worn right to the edge and some I have not. Any modern sport or sport touring tire that I have used will give grip to the very edge. By that point you run a genuine risk of touching hard parts, which may want to lever your bike off the ground. At a recent track day, my traction control saved my bacon when I tried to ask for more than the tire had left to give. However, at that lean angle I was beveling the pegs rather significantly.

[Switchblade]

Depends on how much chicken you have left .

There are all kinds of varibles with street tires but slicks now that another matter .

Roll On ..

[Mohawk]

With a properly designed tyre, the contact patch size will NOT shrink & may in fact get get bigger as you move towards maximum lean.

Sports tyres tend to have steeper profiles that help turn in & they generally have a larger contact patch as they are leaned over, due to tyre carcass deformation under the additional loads imposed, assuming the correct tyre pressure is used.

A chicken strip does not mean anything other than the tyre has never made contact with the tarmac at its very edge, this means nothing. The proper tyre for any bike should still have a small strip once the pegs or hero blobs touch down, i.e. a degree of tyre in reserve. This stops you riding off the edge of the tyre !

Touring or sports/touring tyres generally have a more rounded profile, this gives a larger contact patch when upright, but generally no increase when leaned over. Due to this rounder profile, they can often reach the tyres edge at maximum bike lean. Its all down to the profiles & how the rider rides, upright or hanging off.

If you go to a dealers with a tape measure &/or watch any racing, you can see/check that the foot pegs & case edges/exhausts on sport bikes are higher & set further back, this allows a higher angle of lean & the rear set foot pegs move the lowest point away from the center of lean, thus gaining a few more degrees of lean potential. So if you imagine there is a fixed relationship, between the tyre & the wheel spindle, then more lean demands a tyre with a steeper side profile, to ensure you don't roll off the edge before reaching maximum lean. Sports bikes can reach 60+ degrees of lean, sport tourer maybe 55 max, tourers even less.

So a sports tyre on a tourer will usually have a bigger chicken strip, than the same tyre on a sports bike, all things being equal, as in same rider & 95% of lean used. Plus if you hang off you naturally lean less, so for the same speed/bike/tyre combination, you may have more of less strip left than the next guy.

When I used to do a lot of track days on my CBR600F4, the guys I used to ride with would have no strip & claim all sorts of manliness (hence the CHICKEN strip), but me & my 10mm strips on the rear was faster than them round any of the tracks we played on, so don't EVER get suckered in by the chicken strip BS :)

YMMV as will the size of your strip :)

[checksix]

On a VFR you'll run out of ground clearance before you run out of tire. I'd be more concerned about the former.

[f3racer]

On a VFR you'll run out of ground clearance before you run out of tire. I'd be more concerned about the former.

This is waaay true. My bodywork is on the groud in this picture.

[TNRabbit]

This is where you run out if tire edge on the Michelin Pilot Road 4 tires. Think your VFR has the clearance to hit these angles? LOL

[iamzombie]

As has been said, you'll be dragging bodywork and/or pegs and/or exhaust long before you reach the end of grip on a modern sport/sport touring tire.

[timmythecop]

can someone please explain the difference in front vs back tyre strips. I always have twice as much unused front as rear, unless I am at Tmac, then both front and rear go to 1/16 of an inch to the end. I heard once the front chicken strips were more about braking than lean angle....

typical post TMac front

[Havagan]

http://www.maxxis.com/other-motorcycle-information/motorcycle-faqs

"Front and rear tires have different handling needs. A front tire has a more triangulated profile for steering control, while a rear tire has a flatter profile for bike stability."

can someone please explain the difference in front vs back tyre strips. I always have twice as much unused front as rear, unless I am at Tmac, then both front and rear go to 1/16 of an inch to the end. I heard once the front chicken strips were more about braking than lean angle....

typical post TMac front

[HighSideNZ]

I'm with Mohawk on this one.

There are so many different dynamics that go in to cornering speed and lean angle that road riders that move their weight during a turn will always have more of a strip left than a rider that doesn't hang/lean off the bike.

I'm of the thought that it is up to me to make the decision of where my maximum lean angle is.

With my bike I don't have the standard pegs, and my pipes are tucked up much more than stock, so there is no "witness" when things touch down until the centre stand hits.

I'd much rather have 10% safety margin and chick strips than no margin and a bike rebuild.

Ride to what feels comfortable to you.

Not what others say you should be doing.

[Belfry]

Mmmm. Chicken strips ... I like mine grilled:

[Rush2112]

.....I heard once the front chicken strips were more about braking than lean angle....

'Prolly something to that... as you accelerate out of turns the load on the front reduces and the back deforms more. Front tire sees most of its scuffing trail braking on the way in.

I think suspension geometry plays a role too... some bikes eat front tires and I get 50% more miles out of my front compared to rear

[dutchinterceptor]

Most of you guys are dragging your elbows, right? right?

[Dedofnite]

Haha! of course, Dutch! But only during the crash. Nice discussion. I'll add one thing... during my racing days, I remember always worrying about that "unused" strip of tread when going out on a new set of race tires for the first lap of practice, even though I had plenty of time to scuff them in on warm up. On the street bikes I got into the habit of always scuffing off the chicken strips right after installing new rubber. I just ride around in circles in out in the street, or a clean parking lot, in second gear with the outside peg weighted and inside foot skimming the street until I get the bike leaned right to the edge of the tread. It takes 1 minute and the strips are eliminated. Any one who has pulled out of the Dealership parking lot on new tires with a little too much throttle knows how slick that smooth rubber is. I would rather not risk having to lean to maximum during an evasive maneuver on the street and hitting that slick spot. And since I never lean my bike over that far on street rides anyway , no one has to know how chicken I am!

It's a win-win.

Ded

[Switchblade]

Yeah I have draged my elbow, with one exception , the bike is dragging its elbow also .

Roll On ..

[Rush2112]

Haha! of course, Dutch! But only during the crash. Nice discussion. I'll add one thing... during my racing days, I remember always worrying about that "unused" strip of tread when going out on a new set of race tires for the first lap of practice, even though I had plenty of time to scuff them in on warm up. On the street bikes I got into the habit of always scuffing off the chicken strips right after installing new rubber. I just ride around in circles in out in the street, or a clean parking lot, in second gear with the outside peg weighted and inside foot skimming the street until I get the bike leaned right to the edge of the tread. It takes 1 minute and the strips are eliminated. Any one who has pulled out of the Dealership parking lot on new tires with a little too much throttle knows how slick that smooth rubber is. I would rather not risk having to lean to maximum during an evasive maneuver on the street and hitting that slick spot. And since I never lean my bike over that far on street rides anyway , no one has to know how chicken I am!

It's a win-win.

Ded

I just quickly sand paper the outer edges of my tires after they are mounted so I don't have to worry about hitting the release agent during hard maneuvers... planned or otherwise.

[Dedofnite]

Yeah, but...

...that doesn't sound anywhere near as fun as riding in circles and daring your tires to slip...

Ded

[HispanicSlammer]

Most people ride on the street with higher tire pressure to preserve tire wear. Riding much slower the availability of grip is less but your not taxing it as much. Track riders usually ride 5 lbs less but heat up the tire much more and end up pressureizing the tire with heat. So the contact patch is generally about the same but the grip changes slightly due to heat. Pilot powers are rated to 50 degrees lean angle which no doubt you are not gonna be over that far on the street. Maybe on the track? I've seen motogp riders 61 degrees over and I am just dumbfounded. Getting to the edge is around 45 degrees lean on the rear. You have more grip beyond just the edge.

Sent from my SM-N900V using Tapatalk

[Dutchy]

You have more grip beyond just the edge.

Sent from my SM-N900V using Tapatalk

No motorcycles were hurt in making this!!!

[f3racer]

Most people ride on the street with higher tire pressure to preserve tire wear. Riding much slower the availability of grip is less but your not taxing it as much. Track riders usually ride 5 lbs less but heat up the tire much more and end up pressureizing the tire with heat.

Yeah i run 36/42 as the manual says on the street, but i run 30/30 on the track. My cbr600 race bike was set at 25/23.

[Beck]

It's kinda funny how the technical discussion can sometimes fall into the deep end when talking about "Chicken Strips"......of all things....

Just lean it as far as you are comfortable and what you think your bike can handle and don't try to rub off the strips with the road just for added pose value....