hi im looking into specs on a bike, and it seems that it used to be a 13/23 7 speed. so what does this refer to?

also is it possible to make it into a 13/21 7 speed?

thank you.

7 cogs on the cassette. Numbers are teeth in each cog.

https://www.google.com/products/catal...d=0CIsBEPMCMAY

https://www.google.com/#hl=en&sugexp=...w=1066&bih=532

Gearing can be modified in all sorts of ways. How you go about it depends on the specifics of each bike and what you want to accomplish.

Of course 7-speed means 7 cogs on the freewheel. Multiply that by the number of chainrings on the front and that tells you the possible number of different gears that you have.

13/23 Usually means that the smallest sprocket on the freewheel is a 13, the biggest is a 23. I used to have a 7-speed exactly like this. Probably has 13, 14, 15, 17, 19, 21, 23. In the past almost 20 years I've ridden mostly with 7-speed 13/21 freewheels and those work well for the average person in an area that is mostly flat. In digging through my old stuff I also found an old 13/24 freewheel and a 13/19 freewheel (called a straight block).

You can change your gears to be different than 13/23, maybe a lot different. Depending on the age of your bike you might have a freewheel or you might have a freehub with a cassette. You mainly need to buy a new freewheel or cassette with the gears that you want. How much bigger than 23 you can go depends on your rear derailleur.

really? you don't know what 13-23 means but you know what 13-21 means. IF you are not trolling then why are u asking this question?

^it was purely from the spec sheet. i compared it to the Opus V's and those were 13/21. thats why i asked if it was possible to just make it into that instead of 13/23. thats all.

oh sorrry.