Replacing Rings on a Riveted Crankset?

[Eugbug]

My MTB has a riveted triple ring chainset/crankset and I need to replace it. It is a Suntour SR 180 XR with 24/34/42 teeth. My bike is 21 speed.

Two questions:

1 : Is it in any way feasible to drill out the rivets on the chain rings and replace with discrete chain rings?

2: I have looked online to see what is available in cranksets. The specs of some products indicate that they are suitable for 9 speed. So does the crankset have to match the rear sprockets? Does this have something to do with chain ring spacing?

[nfmisso]

1. no, and more expensive than buy a replacement crankset.

2. I have a 10 speed crankset running with a 7 speed freewheel and 7 speed chain - works smoothly and quietly.

This one will like work fine for you; I would bet your BB, cassette/freewheel and chain needs replacement if your rings do.

[1FJEF]

Yep, under $40 gets you a nice selection. Here's a couple.
http://www.amazon.com/SUNTOUR-CRANKSET-SRST-XCT-175x42/dp/B00DMKK53M/

http://www.amazon.com/Shimano-M131-Crankset-170mm-48/dp/B003ZMDJW6/

[cny-man]

Don't know if you still need help, but it's easier to answer question if you provide the model of bike you have and what problem you are having (wear, gear range?). You would indeed have to purchase a new crankset, and the arms alone might not be compatible with the bottom bracket length, so you might need the BB (bearing/spindle) as well.