Ok, so I was riding around on my Specialized Langster today (like everyday) and I was having a TON of fun skidding around, until I happened to wear through the rubber to the mesh. So it was off to the LBS (Providence Bicycle) for me. I got there, bought a new tire and pedaled home (very cautiously). I also was in a hurry to get the tires swapped because I was going to go the drive through tonight. Well, I guess that I didn't seat everything properly so I ended up blowing the tube . And I had to ride my old "Hobo SS" Schwinn World Sport to my friends' appt. Well, that was a VERY interesting experiance. I was so nervous because there were a couple of times when I went to slow down (not using the break) and my legs whipped around backwards because of the free-wheel. Also I have SPD pedals & shoes, but I couldn't get them off my Langster, so I had to ride with the old school, weighted steel pedals . Well, wasn't THAT fun, not. Anyways, it was a VERY interesting ride, and sure enough it ends up that we didn't end up going anyways and I had to pedal my @$$ home after all that.

I'm thinking of taking the rear wheel from my langster and putting it on my schwinn for now, even though it'll be a 27x1.25 in the front and a 700x23c in the back, but at least then I'll have my pretty little fixed gear, and none of this coasting crap .

Well, never mind on the thought of switching wheels, the link/tooth spaces are different. I just tried it and sure enough the chain won't sit between teeth. Grrrr, oh well, I guess it's a 27x1.25 freewheel for now

ohhhhhh....im telling teh internet that you used underline for non-linked text!

it was for emphasis, it's ok for emphasis, if it was a link on the other hand, then I would have also changed the font color.

Why don't you just fix the flat?

Sounds like you may have a skid patch problem. What size chainring and cog are you running? If you're running something like 45x15, then you are skidding on the same part of the tire everytime. It might be something to look into.

Some guy had a decent site about skid patches and how to calculate them but now its 404'd. send me a personal message if you want to know more, or maybe you already do know, in which case, I hope I'm not being patronizing.

https://www.bikeforums.net/showthread...t=skid+patches

This is what you mean.

That pretty much explains skid patches. You don't want to wear through the same part of the tire every time you break.

how feasable is it to patch this? (see picture) It would take at least 3 patches to cover it. would it be safe? or would it just be more feasable to get a new tube?

edit: I'm running a 48-18

just buy a new tube and save your patches for a last resort when you're out on the road.

I figured, but that does mean that I have to ride the evil bike tomorrow to my LBS.

With the skid spot thing:
48/18 = 24/9 = 8/3 = 2.6666666666
Just wondering though, if I divide 48/18 I get a number with a decimal, doesn't that mean that the wheel goes around a non-even amount, making the spots where you stop pedaling slightly different each time (in my case it goes an extra two-thirds around each time). I don't know much about it, but I may just be drawing completely incorrect conclusions.

3 skid spots with that ratio.

If I were to jump to a 17-tooth cog then I'd have 17 spots right? So I may just do that to save tires/money in the long run.

Yeah, your math is right, but its that "slightly different each time" part that gets you. In your case, there are only 3 spots where that decimal amount can take you.

First, the math for calculating skid patches:
Take your two numbers and find the largest common factor (in this case its 6. 6 is the largest number that both 48 and 18 are divisible by). Then take your cog size and divide by 6. 18 divided by 6 is 3. That is how many skid patches you have. (this is assuming you skid with the same leg forward each time. double that if you skid with either leg forward).

The idea is is that every time you turn the front crank one full rotation, it spins the back cog. when you go 48 teeth around in front, it spins the back one around 48 teeth as well, in this case that is 2 2/3 times (as your math showed). 18 + 18 + 12 (12 being 2/3 of 18). its that 12 you should be concerned about.

If you look at your cog and just pick a tooth and start counting out those 12, you'll hit the spot where your cog will be after one rotation of the chainwheel. Rotate your chain wheel again, and you will go around 2 more times exactly + another 12, so count out another 12. Repeat and repeat. You will see that there are only 3 spots that the number 12 will fall on. That means there are only three spots where your cog is always stopping, hence 3 skid patches.

My awesome drawing may help, or may confuse the hell out of you.

Oh, and yes, if you go to 17, problem solved. Having either number prime will give you the maximum amount of skid patches (aka equal to the amount of teeth on the cog).

ok, thanks for clearing that one up for me, I've tried to read and understand the stuff on the forums about skid spots and I've been COMPLETELY lost, that helped out a lot.

And I love your drawing, it's very, ummmmm, technical