Some people are wondering if Shimano chainrings are compatible with Truvativ/SRAM/FSA crankset. If Shimano’s chainrings have the same chainring Bolt Circle Diameter (or BCD) as your crankset, then the short answer is yes.
For example, if your bicycle crank is compatible with BCD 64/104 chainrings, then any chainrings with BCD 64/104 should be compatible with your bicycle crank.
But with the Shimano middle chainring (with BCD 104), there may be one problem, because, in around 2008, Shimano changed the “ears” of the middle chainring, and although BCD is still the same, the middle chainring may be incompatible with your crank. And you can face this problem, even if you have old Shimano cranks. But you can fix that with the help of a file or a dremel.
The first and third chainring doesn’t have this problem and fits fine.
New chainring doesn’t fit?
I was trying to build a new budget touring bike and wanted to use some old bicycle parts that I already had. I had a good Truvativ bottom bracket and a Truvativ crankset which was missing one chainring – the middle chainring. Having found an inexpensive middle chainring from Shimano with BCD 104, I bought it.
But it did not fit, but after that, I looked up information on Google and found a solution to the problem.
Shimano Chainring on Truvativ/SRAM and FSA Crank
If the Shimano chainring you bought is not compatible with your Truvativ/FSA crank (but it has the right BCD), then you will need a file or a dremel, and CD/DVD marker.
The thickness of the tip of my CD/DVD marker was about 1mm. Put a mark using a CD/DVD marker on the “ears” as shown in the photo, this will help you control the curve of the “ears” and not to cut any excess material.
Now you must cut this mark with a file or a dremel. After you’re done, attach the chainring to the crank, look at how much more remains to cut and apply new marks. It is necessary to cut off about 2 mm on each ear, but after cutting 1 mm, further, control the cut and do not hurry to cut a lot at once.
That’s how the chainring looked after the cut.
Done. It fits perfectly.
I hope this helped. Have a good ride 🙂