Skid Patch mystery
 

I'm currently running a 46x19 gear ratio, which should give me 19 skid patches if I'm not mistaken.

I've had my fixed gear for a little over a month, have ridden it quite a bit since then (around 5 long rides a week) and I'm a little confused as to how I wore a hole through my tire today.

I was skidding a decent when I first got it just to get the hang of it, as do ride brake-less currently. However, after the first week or two I stopped skidding everywhere, as I don't really have any need to stop on my rides (all rural roads).

I noticed that my tire was wearing very unevenly, and appeared to have one large skid patch with about 6-7 other smaller ones around the tire. Today on my ride I got a flat, went to look at my tire and the larger skid patch had worn through to the tube.

The tires were pretty cheap, and that would explain any premature wear. But my question is, why did my tire wear so unevenly? Is there something that I'm missing about skid patches, or was it possibly just really bad luck that I kept skidding in the same spot?

Thanks for the help!

What happens when you use a cheese grater on cheese?

You grate the cheese.

What happens when you use the asphalt on your face?

You asphalt your face.

What happens when you skid on one of you 19 spots?

You 19 spots one of your skids.

length of skid?

Pulling a gnarls barkley a block long will probably cause you to wear faster

skidding in general is wasting your tires.

Only time you need to skid is when your picking up chicks.

To stop there is a great tire saver. But im not telling you, Cause it would let you skid inifinte and no one wants that.

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Each spot has a 1 in 19 chance of skidding each time you stop. That doesn't mean a given patch will skid on every 19th stop. However, eventually, the randomness would nearly even out the patches. But it sounds like the patches were getting worn so quickly, one got worn through before it could even out.

A lot of the '19' patches are within a inch or two of each other, so it's kinda like 8 inches of your tire gets worn... From what I've noticed. When riding brakeless it helps when maintaining your drive train, spin your tire a couple cog notches so your are skidding on different parts of the tire. It will help you keep tires longer. Riding brakeless is fun no doubt but you don't need to skid every time you stop. Learn to back pedal and make smart decisions to keep that tire. I ride brakeless and go through a gator skin every 8 months... and I ride 6 days a week.

take the chain of and spin the wheel a bit every few weeks

...get brakes. If you are riding out in the country you aren't even getting street cred for riding brakeless.

I was running a soma everwear for a while, and with 17 skid patches I got a flat spot that annoyed me enough to ditch the tire while it still had life in it.

What happens is that if you skid in 1 spot and wear it any amount, you are now more likely to skid in that same spot if you try to start a skid anywhere within a few inches, cause the tire will naturally stop at where it is the flattest. It's not noticeable for a long time and if you never develop a flat enough spot to begin with may never happen, but all it takes it one tire stomp while going 20 and leaning back hard to avoid that car to start a flat spot

actually unless you can skid with either leg back you only have half of the skid patches so if you favor your right over your left for instance you only get 9 skid patches

Get a brake and stop complaining about ruining tires, brah.

Think about this for about five seconds, then reconsider its efficacy.

No, this is wrong.

educate yourself: http://www.allcitycycles.com/tech/gear_calc/

It might be worthwhile to rotate the chain a link or two around the cog though. Same idea as rotating the tire on the rim about half the distance between spots, but you probably have to take the wheel out to rotate the tire so that usually doesn't make sense. Too late now.

And if you have 18 possible skid patches, you have a 1 in 18 chance of hitting any particular one... but you might be out there on the statistical curve of randomness that just happens to get the same one 2 or 3 times out of 18.

Forty-six by 19 comes out to 63 gear inches; a very practical gear ratio.

At that gear ratio, you don't need to skid.

Stop skidding.

You can stop just as quickly by back-pedalling, but you will need to practice and learn how to do it.

I like 63 gear inches and ride that ratio on two of my fixed gear bikes.

Spoon brakes are the new brakeless anyway.... Brakeless was so 2006.

http://farm5.static.flickr.com/4078/...d40d335cf7.jpg

Pardon me if I'm being dense or slow, but how would rotating the chain do anything? I'll admit the idea of skid patches and the whole relationship between crank, cog, and tire was VERY difficult for me to grasp at first, but I think I understand it now.

Imagine if the cranks are parallel to the ground, the position of the cog relative to the tire is fixed, and will not change when you rotate the cranks. Do one full crank rotation and you will have a different spot on the tire facing the ground (the hypothetical skid patch of that rotation), unless of course your gear ratio only gives you one skid spot.

With the cranks in a fixed position, moving the chain on the teeth of the cog and chairing will not effect the relationship between crank, cog, and tire. Therefore your skid spots would still be the same. In order to "rotate" your skid spots you would either need to shift the position of the cog (not really possible without having it be too loose) or rotate the tire (relative to the rim, and therefore the cog) a couple inches (or maybe only one inch) in either direction.

edit:

having a rough time wrapping my head around this right now, but I think you're almost right. If you take the chain off of the chainring, then rotate the crank (no need to move the chain) that should change your skid spots. I think. . .

Best way to look at is imagining a 1:1 gear ratio with 2 skid patches, moving the chain a couple cog teeth will move the skid patch over a bit... thus extending the life of the tire.

Correct - imagine you have a gear combo with four skid patches (90° apart), and you rotated the tire 45° without moving the rim - now you'd have four new skid patch locations half way between the old skid patches.

You can do the same thing by moving the tire on the rim, moving the chain on the cog, or moving the chain on the chainwheel. In practice, any time you take the wheel out or change the chain you'll almost certainly not get it back in the exact same orientation anyway. This isn't really an issue for most people unless they skid a LOT... it's just fun to think about.

Skidding is a horribly inefficient way to stop, in addition to the cheese-grater effect that it has on your tires.

When you skid a tire, that means the tire has lost its traction or grip on the road, so you've lost most of your control. Even in a braked stop, a skidding tire means you've lost traction, and therefore lost the braking power on that wheel, so you have to let off the brakes a bit until you stop skidding and regain control.

Skid stops look cool, but they have a price -- greatly accelerated tire wear, plus a good chance at crashing because of lost traction.

Get some brakes, or watch your speed and learn to slow by back-pedaling. Also, be aware that brakeless bikes are okay on the velodrome track, but they're not legal on public streets and roads. Check your local laws.

Brakes seem to be the new brakeless around here. People have ridden safely for many miles and many years without brakes. If you're gonna ride brakeless get yourself a good rear tire (Gatorskin) and don't complain about tire wear.

You can ride brakeless without skidding if you gear down to 63 gear inches, learn how to spin, and learn how to back pedal.

Stop skidding.

It depends. Laws in Indiana (at least) only require that your brakes be able to lock the wheel on clean, dry pavement, which obviously fixed-gear riders can with their legs. I don't think there are actually many places that make bikes without brakes illegal to ride.

Brakeless bikes may not be legal but unless you have a full factory set of reflectors and a bell, your bike is not up to code anyway here in NYC.