MARVIN2006

cassettes some have 11-23 t ,another 11-30 t , other have11-32 ,or 11-34 ! what is

the difference ? do more teeth on firts gear means more easy to pedal up hill ?

thanks ,M , St

JunkYardBike

Yep. Larger sprocket on the rear means you need to pedal a greater distance on the front gear to move the wheel the same distance you would with a smaller rear sprocket. Less force required, but you will be pedaling more revolutions.

Sheldon Brown's gear calculator: https://sheldonbrown.com/gears/

wmelton

What does the "T" stand for (11-23T)? I've noticed some cassettes have it and some don't.

masiman

I think just an abbreviation for (T)eeth.

San Rensho 

To understand the "teeth" on a freewheel you need to understand gearing. If you divide the number of teeth on the chainring by the number of teeth on cassette and multiply by 27, that gives you the "gear inches" or gear size that everyone refers to when they talk about gearing on bikes.

To put it in perspective, most one speed bikes, cruisers etc., have about a 70 inch gear. On a multi speed bike, thats about a 52 tooth CR and a 20 tooth cog. A really big gear (hard to pedal, flats or downhill only) is about 110 inches, which translates into a 52 tooth chainring and a 13 tooth cog. A fairly small gear (easy to pedal and to use going uphill) is around 45 inches, which roughly translates into a 40 tooth CR and a 23 cog.

Sheldon brown has a gear calculator and chart that are very useful.