Shinkers

Quick question, I may be starting a new project, and was wondering how many teeth you can add/lose on the rear cog with standard track dropouts, and still be able to use your existing chain without adding/removing links?

Also, the chainring and cog I'm running are 3/32. Would I be better off using 3/32 single speed specific chain? Or will any 3/32 chain work fine?

Thanks!

JeremyLC

I don't know the actual limits, but I get away with a 15t cog on one side of my wheel and an 18t on the other without having to change chains. I have a 48t chainring, so this setup gives the option of ~70 inches or ~86 inches.

TejanoTrackie 

For every cog tooth you add or subtract, the wheel's axle moves approximately 1/8" in the dropout.

Steev

Is that right? Isn't it every tooth adds 1/2" to the chain length, 1/4" to top and bottom therefore 1/4" movement at the drop-out.

TejanoTrackie 

Nope. It adds 1/2" to the circumference of the cog, but the chain only covers about 1/2 of the cog circumference, so you divide again by 2, which gives you 1/8".

DiabloScott

Also if you set the chain length on the larger cog with the axle as close to the BB as possible, you'll be able to go down smaller with your smaller cog because you'll have the most room to play with in the fork ends.

bowzette

I can use 14-18 with 46 chainring. With 650C wheel this gives me 80-63 gear inches.

Shinkers

Perfect. That's exactly what I'm looking for.

This is what I plan to do.

I'm hoping to be able to use a 16t and around 20t on the other (as big as I can fit...)

Thanks guys!

Shinkers

Oh, and does anyone have any input on using a multi-speed chain on a fixie/ss?

Next question, is there any benefit to using a crank set with an integrated chainring on the right crank (sorry, not sure if there's a technical term. Think Shimano Alfine cranks), or is using a chainring of choice paired with a spider and crank just as good?

TejanoTrackie 

A multi-speed chain is 3/32", so it can be used if the chainring and cog are also 3/32". The advantage of using a regular 3/32" single-speed chain is that the pins are a bit longer, such that they protrude beyond the outer chain link plates, making it a bit easier to assemble the chain.

There is no advantage in using a crank with attached chainring, since you cannot remove it to change the gearing or replace it when it wears out without replacing the complete crankset. Usually you find chainrings that are swaged onto the crank arm in cheaper cranksets, and better quality cranks typically use separate chainrings that bolt onto the crank arm spider.

Shinkers

That's exactly what I needed. Thanks!