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Discussion Starter #1
Recently fitted a new Pirelli Supercorsa SC2 200/55 to my bike and I almost never see the Traction Control light come on

Bike Spec: 2016 GSX-S1000F, full system, K&N air filter, Remapped (correct fueling, optimized ignition, restrictions removed), -1/+3 gearing, Ohlins GP rear shock - Not been on a dyno yet but feels a lot faster than standard.

In the last month/1200km I haven't seen the TC light once (or felt it slip), I don't drive slowly and I used to see the light a lot. Last night i managed to get the light to come for a short while with a full WOT standing start with heavy rain and a slippery road using TC3.

Is this

a) because a combination of 200/55 and Supercorsa SC2 is incredibly grippy

or

b) The 200/55 has a 5% larger circumference which may mean the rear wheel has to go 5% faster before the traction control notices?

Are the front and rear speed discs the same as the front and rear tyres are 4% different in circumference

But otherwise really happy with bike like this!
 

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Recently fitted a new Pirelli Supercorsa SC2 200/55 to my bike and I almost never see the Traction Control light come on

Bike Spec: 2016 GSX-S1000F, full system, K&N air filter, Remapped (correct fueling, optimized ignition, restrictions removed), -1/+3 gearing, Ohlins GP rear shock - Not been on a dyno yet but feels a lot faster than standard.

In the last month/1200km I haven't seen the TC light once (or felt it slip), I don't drive slowly and I used to see the light a lot. Last night i managed to get the light to come for a short while with a full WOT standing start with heavy rain and a slippery road using TC3.

Is this

a) because a combination of 200/55 and Supercorsa SC2 is incredibly grippy

b) The 200/55 has a 5% larger circumference which may mean the rear wheel has to go 5% faster before the traction control notices?

Are the front and rear speed discs the same as the front and rear tyres are 4% different in circumference

But otherwise really happy with bike like this!
after putting s21 and a 55 rear i dont see my tc light come on at all now unless wet, on the standard tyers it would flicker like a christmas tree
 

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always fun to try different setups hey?

Recently fitted a new Pirelli Supercorsa SC2 200/55 to my bike and I almost never see the Traction Control light come on

Bike Spec: 2016 GSX-S1000F, full system, K&N air filter, Remapped (correct fueling, optimized ignition, restrictions removed), -1/+3 gearing, Ohlins GP rear shock - Not been on a dyno yet but feels a lot faster than standard.

In the last month/1200km I haven't seen the TC light once (or felt it slip), I don't drive slowly and I used to see the light a lot. Last night i managed to get the light to come for a short while with a full WOT standing start with heavy rain and a slippery road using TC3.

Is this

a) because a combination of 200/55 and Supercorsa SC2 is incredibly grippy

or

b) The 200/55 has a 5% larger circumference which may mean the rear wheel has to go 5% faster before the traction control notices?

Are the front and rear speed discs the same as the front and rear tyres are 4% different in circumference

But otherwise really happy with bike like this!
Sounds that you are having some fun experimenting (you know better than some that hasn't tried the 200, you answer your own question, and apparently the bike can handle it, hopefully nothing is affected negatively) !
Nice to hear different points of views.;)
 

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Sounds like they perform better, and just with the name Pirelli I'd expect as much, looking on their site the list the SCII as having the best poor-road performance amongst the Supercorsa line.

You'd have to measure the actual final tire circumference and compare front:rear ratio of stock to current config to really know how much difference there is. Considering traction control is meant to operate only when needed and while cornering and with various wear patterns... I don't think the new profile is too much error. TC also self calibrates at 3mph on every start-up. If anything, I'd expect it to trigger too often, or error out at the 3mph.
 

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I would say it mostly down to better tires. The stock tires IMO were junk, mine were about to the chords after 2500 miles. A taller tire should in sense make the rear speed sensor turn faster which should make the TC kick in more, but the extra grip from the taller and better tire over compensates. But my TC light stays on since I turn the dang thing off.
 

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Discussion Starter #6
A taller tire should in sense make the rear speed sensor turn faster which should make the TC kick in more, but the extra grip from the taller and better tire over compensates. But my TC light stays on since I turn the dang thing off.
Sorry, but you are the wrong way about, the taller tyre makes the speed sensor read slower not faster
 

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I would say it mostly down to better tires. The stock tires IMO were junk, mine were about to the chords after 2500 miles. A taller tire should in sense make the rear speed sensor turn faster which should make the TC kick in more, but the extra grip from the taller and better tire over compensates. But my TC light stays on since I turn the dang thing off.
cords showing at 2500 miles.....man o man you must be riding hard...holy cow....thats just crazy skill level :eek:
 

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I would say it mostly down to better tires. The stock tires IMO were junk, mine were about to the chords after 2500 miles. A taller tire should in sense make the rear speed sensor turn faster which should make the TC kick in more, but the extra grip from the taller and better tire over compensates. But my TC light stays on since I turn the dang thing off.
Sorry, but you are the wrong way about, the taller tyre makes the speed sensor read slower not faster
Actually you are both wrong. The sensor is fixed and doesn't turn and it reads just the same as it always has. It's the wheel speed relative to the front one which is different:D
;)
 

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The sensors basically read RPM of the wheel. Larger radius means larger circumference, means few rotations for the same distance. So the reading of the sensor, for the same road speed, is lower with a larger tire. If the front profile is unchanged, the ratio of readings front:rear is a higher ratio with a larger rear tire.

Basically, Chris is wrong, Paul is right, and I don't know if I'm interpreting all Beaker is saying correctly but it seems part right and part wrong.
 

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Discussion Starter #11
Actually you are both wrong. The sensor is fixed and doesn't turn and it reads just the same as it always has. It's the wheel speed relative to the front one which is different:D
;)
NOT wrong, The sensor is fixed but as the tyre has a bigger circumference it turns more slowly and thus "reads" the cutouts more slowly as they pass the sensor more slowly for any given road speed.
 

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I think it's a combination of both: (mostly) better traction, and potentially slower reading of rear wheel speed relative to front wheel speed.


Road speed (mph) is measured from the front wheel sensor so changing the rear tire size shouldn't affect the speedometer. A larger tire on the rear will make the bike see a different ratio of front to back wheel speed, and that ratio is what drives traction control. Larger rear tire = slower wheel speed at the hub for a given road speed or front wheel speed.


Traction control comes on when the rear wheel speed becomes some amount greater than the front wheel speed. If you lose traction under power in the rain, the rear wheel speed spikes relative to front wheel speed. If you wheelie, front wheel speed slows down relative to rear wheel speed.


A larger tire on the back could theoretically make the traction control system less sensitive, IF it doesn't have some kind of calibration built in to accommodate changes in tire diameter.


The stock tire is junk. I never felt confident pushing it too hard on either of my 2 bikes. 'Fortunately' they both got nails in them pretty early on so I didn't have to put up with the stocker for too long.


I have traction control set to '1' and I don't notice my light come on - almost never (it also doesn't rain here much). It does let the front wheel come up and maybe I limit how far before the TC kicks on.
 

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A larger tire on the back could theoretically make the traction control system less sensitive, IF it doesn't have some kind of calibration built in to accommodate changes in tire diameter.
The system does a self check every start at 3mph. I assume, but do not know, that it calibrates at this speed as well.
 

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doesnt a 55 bring the speedo error a little closer..by a few mph...or am i thinking gearing...i understand speedo measures at front i dont see how mph error would change but ...whats the bottom line...thanks
 

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doesnt a 55 bring the speedo error a little closer..by a few mph...or am i thinking gearing...i understand speedo measures at front i dont see how mph error would change but ...whats the bottom line...thanks
On bikes that read speed at the gear box, changing sprockets and/or rear tire size will change the error. But not on ours, zero impact. Only changes to the front tire would change speedo readout, or an inline corrector like Speedohealer.
 

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how about rpm...will it read a tad lower for same mph
Hmm, gonna work this one through as I answer, not certain off the top of my head. As far as units of measure and ratios, I'm just gonna pull some **** outta my ass, we're simply looking for how the ratio changes (higher or lower), so using real numbers doesn't matter, and bullshit numbers are easier to use. If there was originally some fixed ratio (there is and it depends on the gearing) between one rotation of the engine, and one rotation of the wheel, lets call it 2:1 engine to wheel; that ratio is unchanged by changing the tire size (but could be changed by switching sprockets). Lets also say the circumference of the wheel is 1, so every two turn of the engine is 1 full unit of distance traveled by the bike, so we also have a 2:1 engine rotation to road distance ratio. If the new tire has twice the diameter, then it has twice the circumference, so one full turn of the wheel is twice the distance. This means the new engine rotation to road distance ratio is 2:2 or 1:1. Over the same unit of time, this means the old ratio would have given 2 rotations per unit time to 1 unit of distance per unit of time; but doubling the tire circumference reduced this to 1 rotation per unit time to 1 unit of distance per unit of time.

So, yes, larger tire diameter means lower RPM for the same MPH.
 
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