Some Questions Fixie Beginner
 

Hey,

I'm from NYC and most LBS around here try to rip off people when it comes to Fixed Gear things. But to cut to the chase my questions is about cogs.

Since I am going to begin ridding a a fixed gear, which type of cog do you suggest teeth wise, and also how does the number system work on going up is more difficult or going lower?

Also, since I am planning on buying the cog from the milwaukee bike site, i was wondering which size should i get since i really dont know the difference between the 1/8 over the 3/32. i have a suzue flip flop hub.



-Dave.

Don't cheap out on your cog. Get something decent, Dura-ace, Surly, EAI. No need to blow $30 on a cog but don't be tempted to buy that $10 cog as opposed to the $20 Dura-ace one.

As for 1/8 or 3/32, that depends on what the rest of your drivetrain is. 3/32 is going to be easier to find chainrings for. This is the standard chain width for derailleur gearing. 1/8 is standard track gearing and until recently, most track stuff came in 1/8. There's no real reason to use 1/8 nowadays except street cred and tradition (which is enough reason for me to use it).

As for number of teeth....I have no idea what type of gearing you like to ride. Take a look at the rabbit singlespeed calculator or Sheldon Brown's gain ratio calculator to get a general idea. In fact...just take a look at Sheldon Brown's fixed gear page. It'll tell you lots of things I'm too lazy to type out.

higher the # of teeth, easier/less resistance the ride is going to be. aim for a gearing of around 70 for a beginner such as yourself.

http://software.bareknucklebrigade.c...it.applet.html

^^input your chainring size so you can see which cog will get you to around 70.

as for cog/chainring-wise, go 1/8th, main reason being 1/8 chains are half the price of 3/32's.

I would second the dont cheap out on a cog idea. 1/8th is what I'm running at the moment, its a little wider than 3/32, I heard somewhere once that its harder to throw a 1/8th but I have no idea if its true, I cant think of any practical explanation of why that would be. As for gearings I think 44/17 is pretty common, I rode a 40/16 for a while and liked it a lot. I suppose it really depends on your riding conditions, but 70 inches ish is a good place to start.

Really? All the LBS's are trying to rip you off? Where are these shops?

More teeth on a rear cog = easier ride
More teeth on a chainring = harder ride

3/32 is quieter than 1/8, but the chains don't last as long but they are obviously lighter. If you're going to buy a good cog, at least buy a good hub and lockring (dura ace) to match.

No amount of NJS gear is going to help you if you bought a crappy hub.

Most 3/32 will be road chains, and thus will be designed to derail easier to facilitate shifting. 1/8 doesn't have to worry about this. In practice it makes no difference if you have your chain tension setup right. This is pure speculation but 1/8 chains are heavier and thus bounce less = less chance of throwing it off the chainring/cog.

Where can you buy $20 dura ace cogs?

Your ideal cog size for you depends on your crank (chainring) size. You should ideally start off with about 70 gear inches which is like running a 16 tooth cog with a 42 tooth chainring, for example.

they can be found online or 3rd party. heck i'm selling a 16t BNIB with Lockring BNIB for 32$ shipped

I think bens cycle or milwalkee bicycle or whatever (its the same website) had some dura ace cogs for 20 when I ordered my cranks and bottom bracket there, sadly I needed a 17t and they only had 13-16t ones. :(

Edit: they are 18 dollars.
http://www.benscycle.net/index.php?m...th=188_190_487

Dura Ace tops out at 16t. I like EAI if you need bigger than that.

Oh dang, I didnt know. I found a nice beefy Surly cog on the cheap(ish) somewhere, it was on sale so I purchased. They seem to get good reviews and its just so I can mess around with my gearing and to match my 1/8 drivetrain.

The deuce you say!

The bigger the cog, the easier the spin. Mathematically: Chainring teeth / cog teeth gives you a gear ration. The smaller the number, the easier the spin. Make the number to small, you'll be pedaling like a mad man and going nowhere fast.

Gear ratio tends to be a my dick is bigger than yours game with the hipsters. Do yourself a favor and start out with something like a 42 or 44 in front and 15 or 16 out back.

Wow,

thank you guys for the input it has been a lot of help. i forgot one more question whats the story with bottom brackets, since i stripped my motobecane i really don't know what the bottom bracket size is I have looked at the axle thing but it just says s p 83 or something like that. Is there way to figure out the mm size Thanks a million honestly. gonna be the first on in my neighborhood in queens to ride a fixie =D

-dave

I believe your motobecane has an english bottom bracket, if that helps.

dear dave,

thank you for putting all your questions in one thread, even when you thought of new ones. i wish that more new kids were like you.

love,
conor

p.s. did you strip the threads on the frame? or just the bottom bracket? also, the length of the bottom bracket depends on the cranks you're using.

Oh ok, by bottom bracket size I thought you meant thread size in the bottom bracket shell of your frame. The length of the bottom bracket depends on the cranks, I think 107mm is pretty common and sugino uses 103mm a lot.

well i dont mean as in stripped like i cant take it out any more i mean as in i took everything off the bike remember seeing the motobecane cranks saying 170 but as in the axle part or bottom bracket w.e. that part is(sorry for the bike illiteracy) i have no idea but thanks for telling me that its an english part. at least that kills the part that i should not purchase an Italian Bottom Bracket.

Haha, yeah, those cranks are 170mm crank arms. If you are looking to keep the cranks, find out what cranks are on it and it should help people tell you what bottom bracket you need. If you have a motobecane messenger they come with truvativ touro cranks. I looked em up and it appears your best bet for a 42mm chainline would be a 107mm width bottom bracket.

Edit for clarity: you want a 42mm chainline because it is standard on track wheels.

Your bb is 1.37" x 24 TPI and some axle length which you can determine by just measuring your current bb The problem with BB length is that it depends on the crank you are using. So select the crank first then worry about the BB.
Bah with shipping it's no better than local.

trackstar or king kog is only going to be like $5 more expensive and you can talk to them about what you need.

but if you don't have $5 I suggest you take up banking instead of fixed gear bikes

Not to ruin your fun, but depending upon the vintage of the frame, your bottom bracket might be french threaded, which will make things much more difficult for you. Check your frame: if both cups tighten clockwise and loosen counterclockwise, it is french. If the non-drive side has the opposite threading, it is english.

I spoke to them already but i like to double check everything to make sure i dont mess up.

oh damn i never thought of that well to take out the whole bb you pin spanners.

Sorry, I thought you had already removed your bottom bracket.

Do you have any idea how old the frame is?

I don't want to discourage you, but vintage french bikes are often a pain to work with.

lol your not discouraging, i removed a the crankset and a part of the bottom bracket like one side i was able to take it off with a wrench but the other side i needed the pin thing as for age of the bike i dont think its that old. Man i hope im not getting annoying with all these questions.

Well, you seem to be doing something right. Most of the time we come together and flame people instead of helping them.

Back to your BB though, take the frame to an LBS and have them measure the width of the BB shell. If it's English, your BB options are very open. If not, well then, I hear you can use a Shimano UN-72 BB and replace the cups with custom Phil Wood cups to fit a French threaded BB.