Anyone know how much a new sprocket cost for a Dahon D7 ? I found this on Amazon but have no idea if it will fit my bike:

https://www.amazon.com/cassette-13-26...5585376&sr=8-2

Yes, that will fit. You can find cheaper at various places. One is here https://www.bikeman.com/store/merchant.mvc? where they start at about $18.95. You should be able to find SRAM cassettes in the teens. Maybe Nashbar.com as well.

Thanks for the info. If sprockets seem to cost almost the same as a chain, does it make sense to replace both the same time? I have around 5000 miles on my original chain/sprocket and am wondering if should replace both or just the chain? The sprocket is showing signs of wear as some teeth are very sharp and pointy.

one thing to consider, though, is whether or not the Dahon D7 has a freeHUB or a freeWHEEL.



https://www.sheldonbrown.com/free-k7.html

It looks to me that the D7 on the Dahon website uses a cassette (which mates with a freehub) instead of a screw-on type freewheel.

In either case, unless you have the right tools, you will have to take it to your local bike shop. They can tell you whether or not you have a cassette or freewheel.

..and those things is cassettes, not sprockets. Not to be mean or anything, just a wery important detail..

I have a 2007 dahon D7 and believe it uses the cassette. But my 2004 Boardwalk is a freehub. For tools, I assume this is the main one I'll need:

https://www.amazon.com/Tacx-Sprocket-...5601624&sr=1-3

Replacing both at once makes very good sense. A new cog in a freewheel or cassette will wear more quickly if used with an old chain.