Singlespeed & Fixed Gear - Brakeless!

I went to my local bike shop yesterday and used their stand and tools. I changed my cog so i have a lower gearing now. I also changed the fork and put my track fork back on.

What an effing beyotch it can be to take a lockring off. Grrr.

Having a lower gearing really helps with skidding and stuff. I went from 77 gear inches to 72. while i can't tell a huge difference in terms of pushing on flats, i can tell a difference climbing and skidding. What a relief, it feels really good.

Also, I am now able to bust impromptu (sp?) skids, meaning i can do those short sexy quick skids instead of setting up, getting way low, and skidding way long.

word.

how is it going fast, can you still go as fast as you could, or do you find yourself spinning out too much?
im on 86.5 inches, i can get to 30 and then i start to spin out and bounce on my seat :D

Funny. I just started thinking about getting a new fork so I could add a brake to my Gios. It soon may be my only bike, so I would be riding through some hairy downtown traffic. Plus I'm rolling on tubulars......
Good luck!

get a helmet. please.

how is it going fast, can you still go as fast as you could, or do you find yourself spinning out too much? im on 86.5 inches, i can get to 30 and then i start to spin out and bounce on my seat :D

You should actually gear down and work on your spin or take a look at your cranks. That's only about 120 rpm which is pretty low when you consider that your target cadence should be around 90 rpm (which is around 23 mph at that gear) for optimum efficiency and power.

With some conditioning, you should be able to hit 150 rpm without too much trouble. That's around 39 mph on that gear.

i can go at 23 fine, but 30 is a bit to much. i dont think its my spin technique, coz ive been riding for a couple of years all the time...
i have 165's but so does everyone?
how do you work out the rpm to mph?

Another question, how do you calculate gear inches?

you get someone else to do it http://www.sheldonbrown.com/gears/

i can go at 23 fine, but 30 is a bit to much. i dont think its my spin technique, coz ive been riding for a couple of years all the time...
i have 165's but so does everyone?
how do you work out the rpm to mph?


see: http://www.analyticcycling.com/GearCadenceSpeed_Page.html

TIP...

What were you running front and rear gear wise?

Me? 48 x 15

Another question, how do you calculate gear inches?

= (Chainring teeth / Cog teeth) x Rear Tire diameter (this varies with tires and pressure)

From 44x15 to 44x16

question. have you guys heard anything about it being easier or more to dfficult to lock up the rear depending on the combination of teeth on cog/chainring. I'm not talking in terms of a high gearing.

i can go at 23 fine, but 30 is a bit to much. i dont think its my spin technique, coz ive been riding for a couple of years all the time...

Your technique won't be as tight as it should be if you've been mashing that gear the whole time.

I top out about 38 mph ona 77" gear and I know there are folks here who spin faster than me, too.

question. have you guys heard anything about it being easier or more to dfficult to lock up the rear depending on the combination of teeth on cog/chainring. I'm not talking in terms of a high gearing.

heard? nope
mathematically, i dont see a reason for it... still force vs work... crank length, though, would make a difference

There is a skid patch zone. I remember being baffled by it. Without rotating the tire it will only skid on certain places depending on the gearing. Ken Cox's 48x18 thread has a post about halfway down. I remember reading that link, but it seems to be down now.

edit: link to thread (http://www.bikeforums.net/showthread.php?t=103530&highlight=skid+patch)

Your technique won't be as tight as it should be if you've been mashing that gear the whole time.

I top out about 38 mph ona 77" gear and I know there are folks here who spin faster than me, too.
that is pretty amazing...

set me straight here, i'm not hip to yall's skidding, but from the title it sounds like you just lock up your rear wheel and skid to a stop. Why, if i am correct, would you increase your stopping distance by skidding all the while not having any brakes?

the number of skid patches isn't going to affect the easy/difficulty of skidding, just the resultant tire wear. skidding difficulty seems contingent upon two things -- difficulty of your gearing ratio, and, not unimportantly, the friction coefficient of your tire to the surface you're riding on. that is, looser or wetter surfaces (or frozen) will be easier to skid on. also, the slicker your tire, the easier it will be to initiate a skid. i had this michelin axial pro on my gitane's rear wheel for a little while, and i lost traction a few times just mashing up a paved hill.

question. have you guys heard anything about it being easier or more to dfficult to lock up the rear depending on the combination of teeth on cog/chainring. I'm not talking in terms of a high gearing.


I wasn't talking about the patch zone bit, though i do know about it. And i know about gearing and friction in terms of skidding, wasn't talking about that either. This kid yesterday was trying to tell me that regardless of gearing that certain ratios make skidding easier/more diffiuclt because of the tooth combinations. This made no sense to me either...just checking in to see if anyone else had heard this shet.

sounds like crapola.

really, if you could have read that one link that is busted. I think that might be the deal.

ow well.

question. have you guys heard anything about it being easier or more to dfficult to lock up the rear depending on the combination of teeth on cog/chainring. I'm not talking in terms of a high gearing.
nope, i've never heard of something like that. the only thing that i've heard concerning different combinations is that with a smaller cog and ring the bike will feel harder and more direct, and with a bigger cog and ring more soft and smooth. i think sprinters usually run smaller combinations because of this.

My 2 bobs worth...

46:18 is 69 gear inches.

I worked in SF running 69GI and was fine, except for the Taylor See-saw. Raced MT6 and came 3rd.

Seems to work awright.

Skidding is a blend of frame geometry and inches. But you knew that;)

Tomorrow is week 3 no riding.

set me straight here, i'm not hip to yall's skidding, but from the title it sounds like you just lock up your rear wheel and skid to a stop. Why, if i am correct, would you increase your stopping distance by skidding all the while not having any brakes?

These crazy people have no brakes on their fixies... They like it that way. So skidding, which is not an effective way of braking is still their best emergency brake, because they can't apply enough backpedal force while still pedaling forwards, retaining the pedals. Their deceleration would be roughly similar to acceleration; loooong stopping distance. By locking up the rear wheel, that decreases somewhat and looks cool at the same time. Still crappy braking if you ask me, so brakeless fixers have to anticipate dangerous situations and not go too fast if they want to stay alive. Respect to all of them.

the number of skid patches isn't going to affect the easy/difficulty of skidding, just the resultant tire wear. skidding difficulty seems contingent upon two things -- difficulty of your gearing ratio, and, not unimportantly, the friction coefficient of your tire to the surface you're riding on. that is, looser or wetter surfaces (or frozen) will be easier to skid on. also, the slicker your tire, the easier it will be to initiate a skid. i had this michelin axial pro on my gitane's rear wheel for a little while, and i lost traction a few times just mashing up a paved hill.

Ok, so I don't quite get how it doesn't affect easy/difficulty (though I have no doubt you're right I just want more information). I happen to ride on a 48X16 (which according to that chart has 1 skid patch). So like by this theory, if i understand it correctly, when I skid i am always skidding on the same part of my tire causing uneven wear on the tire (assuming no rotation). ok, so wouldn't it be that with more patches, there are more possible positions for your feet creating a larger margin for error? I mean with 1 patch, your feet could not be in any other place than they are on that one patch. but say, with a 48X17, there are 17 patches and wouldnt that create more than one precise set up for your feet? say, reversing your feet etc?... maybe i am misunderstanding what a skid patch is... but i dont really get this at all (well other than the fact that I want to change my gearing sometime in the near future).

if you always skid, for example, right foot forward, feet at 3 and 9, and have one skid patch, every time your feet are in that position, the same part of the tire is touching the ground... 2 skid patches, the wheel has two positions it could be in when your at 3 and 9... etc, etc, etc...

maybe i am displaying superior math skills (if you think i'm serious, i think you have problems, haha) but lets take the 17t cog which has 17 patches for most of the chainwheels... i have trouble believing that feet at 3 and 9 have 17 different spots on the wheel to be regardless of chainwheel size... but once again, i have clearly superior math skills so take my logic however you wish.haha

color me ignorant but i don't know why this thread is titled "brakeless" when all we're talking about is gear ratios and skidding.

color me ignorant but i don't know why this thread is titled "brakeless" when all we're talking about is gear ratios and skidding.

Because if i posted a new thread about skid patches i feared it would be moved to general cycling discussion

I never ride with a computer, but sometimes I ride with people who have them :c) From that I know I can do at least 27 mph on the flats with a 42x16 (69 gear inches).

From that I know I can do at least 27 mph on the flats with a 42x16 (69 gear inches).

That's a cool 131 RPM's. Spin to win!

It's not very difficult to deflate your tube and shimmy the tire an inch in either direction ocne you start to notice skid patches.

but, golly gee, then the label on your tire won't be placed above the valve!!!

skid patches work by hoe thw number of teeth on the cog fit into the number on the chainring. with 48*16 the 16 fits evenly into the 48 (3 times) which means ony one skid patch. If the number of teeth on cog doesnt fit evenly into the number on the chainring then you try fitting the teeth on the cog into the number of teeth on chainring times 2. if this doesnt fit then times 3. the number of times you must multiply the number of teeth on chainring to find a fit is number of skid patches

It's not very difficult to deflate your tube and shimmy the tire an inch in either direction ocne you start to notice skid patches.


Isn't it easier to just loosen the rear wheel and change its position relative to the chain by a couple of cogs? And then the label on the tyre WILL be at the valve :)