I just bought a fixed crankset off ebay, but the chain size was not listed as either 3/32" or 1/8". http://cgi.ebay.com/ws/eBayISAPI.dll...ht_2010wt_1139
The teeth fit into my road bike's chain, so I'm assuming that the crankset is compatible with 3/32". However, they were marketed as "fixed", which are 1/8". How can I measure the crankset to make sure it's 3/32"?
If the teeth fit your road bike's chain, it's 3/32". End of story. If it were 1/8" the chain would not fit at all.
If you want to measure, get some calipers and measure the thickness of the chainring's teeth.
All my bikes.
What type of cog (3/32" or 1/8") are you running? If you have a 1/8" cog, you can run 1/8" chain on either type of chainring.