# Do tires slip when you take corners tight?



## csh8428 (Aug 2, 2007)

I come from speedskating and I had a question.
I've recently taken up cycling and will soon start racing.
In inline speedskating, if you're going too fast and take a corner too tight, you will slide out and most likely get some nice road rash. If it's indoors, you get a nice floor burn.

Bike tires have far more grip than skates as I've figured out. When I'm taking a downhill mid grade corner at 45mph there's not hint of slippage; whereas if I did that on my skates I'd probably leave most of skin on the asphalt.

Do road bike tires ever just "slide out" from under you?
At what speed/g force/angle does this happen?
What specific tires are more/less grippy than otheres?


Thanx,


Craig


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## Bocephus Jones II (Oct 7, 2004)

csh8428 said:


> Do road bike tires ever just "slide out" from under you?
> At what speed/g force/angle does this happen?
> What specific tires are more/less grippy than otheres?
> 
> ...


1) Yup

2) Not sure of the specifics, but more than you'd think

3) Race tires are generally more grippy but they wear faster.


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## California L33 (Jan 20, 2006)

csh8428 said:


> Do road bike tires ever just "slide out" from under you?
> At what speed/g force/angle does this happen?
> 
> 
> Craig


I've read that a bicycle can't stay upright if leaned more than 45 degrees. I don't know if it's true or not. It usually happens when you hit a patch of something other than road- sand, leaves, oil, etc. It is quite unpleasant.


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## wim (Feb 28, 2005)

csh8428 said:


> Do road bike tires ever just "slide out" from under you? At what speed/g force/angle does this happen? What specific tires are more/less grippy than otheres?


To paraphrase Jobst Brandt's piece at the link: Road bike tires do slide out from under you. They do so without warning and there's no recovery. But on dry pavement, slip-out occurs at about a 45-degree lean angle, which is far more than you could pedal through a corner without experiencing a pedal strike.

IMO, a 45-degree lean angle is also much more than most amateur riders are willing to lean their bike. Many will ride off the road to keep from leaning that much.

http://www.sheldonbrown.com/brandt/descending.html

FWIW, this piece by Jobst Brandt has sparked many an internet flame war. But Jobst usually knows of what he speaks.


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## exracer (Jun 6, 2005)

1. It depends on several things; condition of road surface, condition of tire, tread pattern, etc. On a clean dry road most tires stick pretty good. You have to pay attention to whether any oil has been dropped on the road by cars. 

2. It depends on you more than anything. How comfortable are you with the front end pushing slightly? Or having the back end break loose? Things can happen very fast. You have to learn what your tires are telling you. You need to develope that skill to recover if your tires do begin to slide. You also want to do all your braking while the bike is verticle. Braking in a corner compromises the amount of traction available for cornering. 

3. A race oriented tire (Continental GP4000 or Michelin Pro2Race) will wear faster but offer higher levels of grip and feedback.


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## csh8428 (Aug 2, 2007)

exracer said:


> 2. Or having the back end break loose? Things can happen very fast. You have to learn what your tires are telling you. Braking in a corner compromises the amount of traction available for cornering.


Yep, 
Found that out on my 2nd ride hauling butt down a hill at 45mph. There was a person who decided they were going to drive down the middle of the road instead of in their lane. I was coming out of the corner in the lane going with traffic(this in a neighborhood with no other cars around) locked up the brakes and had a nice little powerslide to avoide the car, but I stayed on the bike 

The 45 degree issue is interesting. 
Indoors on inlines, we can get much farther than a 45 degree angle of our skates, but as long as our body is ~45 or more we won't slip. This is on a polyurethan coated maplewood skating rink floor though, not outdoors. Outdoors is nowhere near that amount of grip.

One thing I have noticed(I'm also a speedskating coach).
Most people on bikes put their knee out to the side when they turn tight.
This is incorrect. If you tuck you knee agains the top bar and lean your hips into the corner, you get a much better apex and acceleration out of the corner. This is from the physics of skating. Many people put their hand down when their get on an extreme edge, but that actually slows you down(but it looks cool). Putting your hand down changes where your center of gravity is by putting if farther around from your hips.You will maintain your momentum much better if you keep you arms swinging. Same concept applys to cycling(physics is phyics). Putting your knee out moves the center of gravity farther away from your hips, and decreasing the amount of force you have pushing down directly through the tires By putting your knee out, you're putting the force more straight down which will decrease your grip and momentum.


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## TurboTurtle (Feb 4, 2004)

You want to lean just a little less than this - especially if there is a row of bricks across the street. - TF


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## IndyFabCJ (Apr 1, 2006)

Nice picture.


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## MR_GRUMPY (Aug 21, 2002)

I'm guessing that it was close to 40 mph. Downhill left turn, on the bell lap.


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## TurboTurtle (Feb 4, 2004)

"I'm guessing that it was close to 40 mph. Downhill left turn, on the bell lap." With only Jonas in front of him. - TF


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