Bike Forums - FSA chain ring replacement

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FSA chain ring replacement

My new chain consistently slips on forceful pedaling. Looks like I have a worn middle chain ring (39T) on my FSA Gossamer triple crankset. I’m having a hard time finding that particular chain ring for the Gossamer series. It seems not any 39T ring will work well. Anyone else run into this situation?

Any 39T ring might not be of the same bolt pattern or have the shifting aids (lift pins, ramps, shift gates...). I take it your LBS hasn't been tried yet? Andy

Exactly. My LBS installed a generic 39T only to find it shifted poorly. They realized the “switching ramps” that come with Gossamer chain rings were missing. The problem might also include incorrect or missing lift pins and gates, as you say.

They’re in the process of locating a ring that has that and will work well. I had thought simply ordering a Gossamer 39T for the FSA triple would be the solution, but easier said than done.

The triple cranks have their middle rings designed for better shifting (with the aids I mentioned) for the granny to middle shift. The double ringed cranks don't need these aids as there's no shift up and onto the 39T ring. That the shop either didn't know this or didn't explain it to you speaks to that shop's knowledge base or their lack of communication motives. We interchange a number of brands of rings on various cranks with little issues when the spec are matched right. We do like to use the same brand rings whenever as the first choice but find some brands shift better then others, even when all have their shift aids. Shimano is still what we call the golden standard. The race face rings shift very well too (and what I personally use on a number of my bikes including our tandem). Dimension and Origin 8 are house brands from major wholesale suppliers and also shift well. FSA is among what we feel are the worst shifting.

Tell your shop that QBP shows both FSA and Shimano 39T 130 bolt pattern rings in stock right now. Andy

Ok thanks Andy, good information. I’ll chat with my LBS and see what 39T they ordered. I think now they originally really did know about the shifting ramps, as they explained how that works to me when I brought my bike in for repair. It looks like the exact 39T with compatible ramps was just not used.

As a note and correct me if I’m wrong, but it seems triples can be more of a headache in repair and adjustment than might be worth it on a cross bike for the granny gear benefit. The derailleurs also seem more touchy and tricky to adjust and fine tune. My second Tricross from a year later is a double, and I’m not sure I really miss that granny for the type of cycling I do.