First, let me preface this by saying, I am still new to the myriad nuances of multiple chainrings/cogs, and derailleurs (I've been a fixed-gear rider for waaaay too long).

I bought a used road bike. It has an 8-speed cassette and a triple crankset. When I got the bike there was a 10-speed chain on it. This was doing nothing but causing shifting problems with the front derailleur. I swapped it out for an 8-speed chain. Now everything seems to be running like clockwork. However, I've noticed a few spots (scrapes marks) on the large chainring where the chain has rubbed during shifting.

Is this normal? Or perhaps the 8-speed chain is too wide and should switch to a 9-speed chain? I have no idea what speed (8 or 9?) chain the crankset was intended for.

Thanks.

Yeah, that's normal. Cranksets usually aren't really picky about 8, 9, 10 speed chain.

Only get a 9 speed chain out of necessity.. like having a 9 speed cassette.

the scraping is part of forcing it up and over the big ring to Up shift ..

its invisible to anyone on your right , Dont over think it..

Scrape marks on the inner face of the outer ring are normal, since the chain rubs there during the shifting process. Chain marks anywhere else on the rings may happen because of the chain dropping, or other handling related events.

It wasn't because of the wrong chain, nor does it matter either way. Enjoy the bike, make it work well, and don't obsess over it too much.

BTW- anticipation a possible future post. Chain marks on the top of the chainstay are par for the course on derailleur bikes, either from chain dropping, or chain slap on bumps. You can keep protect the stay with a "chainstay protector" or accept some cosmetic damage as normal.

I've been running Sram 830 8sp chain on 9sp xtr for a while now. I'm tempted to try one on my 9sp 105 bike.

It is Narrower.. KMC is adequate .. their quick link works well..

Thanks for the input, everyone!

So far I'm really enjoying having the gear options, and learning about maintaining and adjusting my derailleurs--I haven't had a geared bike in over 10 years. I like having the gears so much I think my fixies are feeling lonely in the garage.

Good points about chainslap, FB.

Mrblue, if you didn't adjust chain length check out Sheldon Browns chain length article. It results in shortest safe chain length.

What is interesting is that whomever rode the bike before I owned it must not have used any other chainring aside from the middle one (since that was where the chain was when I bought it). Before I started riding the bike the chainrings were absolutely spotless--not a scrape, scratch, or anything.