Gear ratio effect on stopping/skidding

Wet, slick tar is better, grass is too slow and too lumpy. Course it's softer if you're a gumby and stack it ;)

lpg 46x17!

If God rode fixed, he would ride 46x17.

No way! God would at least know his prime numbers and run 47x17 so he could change out the cog and still have loads of skid patches on the tyre.

Krishna runs 47x17 too I'm told.

Here's a thought.

On my pub Peugeot I've got Vittoria Rubino 25s, the back needs changing. i guess i should go for 23s this time for skids sake?

I like Rubinos alot btw.

Flinging your nuts against your stem is also an excellent way to test if you've tightened your quill enough. Or not.

On my pub Peugeot I've got Vittoria Rubino 25s, the back needs changing. i guess i should go for 23s this time for skids sake?

I can't remember enough about coefficients of friction to tell whether a smaller surface area with with higher weight PSI skids better than larger area with lower PSI

smaller surface = less resistance

It must be i reckon, that's why i get skitty handling turning hard on 23s, but less so on 25s.

"Standard friction equation

The standard equation for determining the resistive force of friction when trying to slide two solid objects together states that the force of friction equals the coefficient friction times the normal force pushing the two objects together. This equation is written as

Fr = ?N

where:

* Fr is the resistive force of friction
* ? is the coefficient of friction for the two surfaces (Greek letter "mu")
* N is the normal or perpendicular force pushing the two objects together
* ?N is ? times N

Fr and N are measured in units of force, which are pounds or newtons. ? is a number between 0 (zero) and ? (infinity).
Applies to static and kinetic

This equation applies to both static and kinetic sliding friction. Static friction is the friction before an object starts to slide. Kinetic friction is the friction when the object is actually moving or sliding.

Static friction and kinetic friction have different coefficient of friction values.
Independent of area for sliding hard surfaces

An interesting result of this equation is that in the case of sliding friction of hard surfaces, the friction is independent of the area of the surfaces. In other words, it is just as difficult to move a 1 square-cm object as a 1 square-meter object, if they both are pressed to the surface with the same amount of force.

This is not intuitive. You would think that there is more friction when the surfaces are larger, but the friction equation states otherwise. You can verify this fact with experiments.
Soft, adhesion, rolling and fluid

In situations where the surfaces deform or there is molecular adhesion, the friction is not independent of the areas in contact. In these cases surface area usually comes into play. This is also true for rolling and fluid friction.

When solid surfaces are soft and deform or when one material is a fluid, the shape of the solid object may be a factor.

Although the standard friction equation still holds, the coefficient of friction may have area, shape and other factors included in it."

it is.

although when you start skidding you move from rolling to sliding, so as long as your wheel is not rolling at all the size of the tyre does not matter, but you will have less resistance stopping it from rolling, and starting it rolling again if you ride 23s as opposed to 25s

yeah so 23s then.

haha.

but we all knew that already. wide tyres are for off road.

I think there is still an unresolved issue regarding molecular adhesion between my stem and balls though
:0

well i had 25s for bouncing over potholes, which they do ok at.

miro_o I think there is still an unresolved issue regarding molecular adhesion between my stem and balls though
:0

baby powder them up, it will reduce this and jock itich

I can't believe i'm taking advice about my balls on the internet!

miro_o I can't believe i'm taking advice about my balls on the internet! from Chris Crash

fixed.

p.s. dont do what i say.

squag so what about the Frisco kids?, like from mash. They dont lean forward at all and just skid away with ease.
I presume they'd have lower gearing for all those hills though

When you get good at skidding it's not that hard skidding without leaning forward, with about 69-70 gear-inches.. also it gets easier when going faster.

edit: oh, and i agree with others that say don't skid on grass, try something less dangerous like wet granite, easy to skid on.

skoota wet grass. easy and soft.

Not a great idea, in my experience. I broke two ribs by skidding on wet grass. It was slippy that when the skid started to goa fraction sideways it just flipped and dumped me, hard, onto my rib cage. oww.

haj [quote]squag so what about the Frisco kids?, like from mash. They dont lean forward at all and just skid away with ease.
I presume they'd have lower gearing for all those hills though

When you get good at skidding it's not that hard skidding without leaning forward, with about 69-70 gear-inches.. also it gets easier when going faster.

edit: oh, and i agree with others that say don't skid on grass, try something less dangerous like wet granite, easy to skid on.[/quote]

its all about weighting, forward for distance, and ease of starting, over the seat for quick stops. its easy to keep skidding once you have started, so start forward and lean back to scrub more speed, then you will get used to skidding closer and closer to the seat.

yeah and when the weighting is right your skidding feels light on the back wheel you can almost pedal backwards...

What frame is that?

A friend is after one (after spotting one in a shop window on holday) but forgot the name of make.

if you speaking about the one in the Kanye West pic, is the Cinelli VIGORELLI

http://www.cinelli.it/scripts/prodotti.php?Id=1&lang=EN&IdBici=459

if you speaking about the one in the Kanye West pic, is the Cinelli VIGORELLI

http://www.cinelli.it/scripts/prodotti.php?Id=1&lang=EN&IdBici=459

Sorry, forgot to attach the picture.

It looks great - would you recommend it though? And how much?

no idea mate, sorry.
for the price just google for a while, them finished item in ebay and more or less you can make and idea of the price

Dang: it's about £500 (=/-) by the looks of it. Beautiful looking frame though.

I've been riding London streets for nearly 10 years now and finally invested in a fixed wheel. A cfew months ago I finally bought my fixed wheel bike from Brick Lane Cycles (their own frame / no logo) as I was on a bit of a budget. Still a fantastic bike though for a first time rider.

I have a question: I would like to start collecting parts and build up my own bike very slowly (a few parts on each payday).

I'm gonna check out loads of second hand shops for a cheap but okay looking (light) steel frame. Is there any thing I should be weary of when doing it this way?

Cheers guys

i also found the first time i could finally skid was on wet slick concrete. it's also quite important to slightly unweight the back wheel as you do the push/pull thing i find (lift bum up a bit). now i can do it fine on dry thanks to my contis too :D

and doing it on a sloped road/concrete helped a lots.

grass is a lots of fun to skid too.