Bicycle Mechanics - New Chainrings: Am I overthinking it?

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pbd
11-19-11, 02:39 PM
Picked up some new chainrings for a song. Current set-up is Rival 50/34 compact (110 BCD), and I picked up a set of Red Black take-offs, also in compact 50/34 110BCD, so I know they will work. The current chainrings have ~1500miles on them, not worn out or anything, but I've been told the stiffer Red rings would improve front shifting, and for how cheap I got them I think they look cooler too.

So I want to go ahead and put these new chainrings on. Chainring bolts are allen heads on both sides, easy enough. Grease the threads, check. Torque spec 8-9 Nm, simple. Don't even have to break the chain. Seems...too easy.

Is there anything I'm missing here? I think I'm just overthinking it. Like the chain, should I replace it? It's measured something like ~.5% "stretched", not worn out by any means, but is it "worn into" the chainrings? Maybe wait until the chain needs replacing anyway (which is no fun at all when I have shiny new bike parts)?

I should probably worry less, but could I get some reassurance anyway?

Thanks

jimc101
11-19-11, 02:43 PM
Replace, don't replace, the choice is yours, if you have shiny parts, it's a shame not to show them off.

As for the chain, if it's only got 1500 miles on it, should have a lot of life left in it, would only replace for cosmetic reasons in your case.
davidad
11-19-11, 06:05 PM
The test for chain replacement is to measure it with a ruler. 1/16" wear in 12" of chain is replacement time. I hang my chain after I clean and dry it and measure 4' of chain. 1/4" in 48" is time for a new one.

MudPie
11-19-11, 06:50 PM
Pretty much you're done. Torquing the chainring bolts is a detail most probably ignore. Mechanically you're fine. Regarding the chain, I'd compromise and perhaps break it and clean it well in a Simple Green bath. And while you're at it, pop off the cassette and clean that too. It'd be a nice clean drive train!