Compact Double question

[preeder]

I'm about ready to make the big (HUGE) splurge and buy a Merlin Camena. I'm driving to Cleveland on Wednesday to do the test ride and make a final decision. Great bike, all Ultegra, extremely good price. My question--the shop owner has suggested a compact double instead of a triple on the front. His advice is that it will shift more smoothly and will be an asset with the small frame size and short chain. He's suggesting a 50/30. I use my granny gear quite a big on hills and at 53 am working to preserve the knees I was born with. Any opinions or experiences?

[Wendy]

I think most triples come with 30/42/52, so the small chainring wouldn't be any different.

[SadieKate]

You need to carefully look at the gearing on your current bike and do the math. There is a gear calculator on www.sheldonbrown.com you can use. You will need to know the number of teeth on your chainrings and your cassette. Changing cranksets can be a huge expense so you need to make a very informed decision.

So, the answer will lie in the combination of the chainring and cassette. You can't look at the chainrings alone.

You may find that the 30T is fine with a larger cassette.

[DeniseGoldberg]

I second SadieKate's recommendation - check the gear inches, and be very sure of your decision. I'd do the gear inch calculation on both bikes and compare the gears that you usually use on your existing bike with those available on the proposed configuration.

There is absolutely no reason that a bike with a triple shouldn't shift smoothly and quietly. I have a triple on all of my bikes - both road and touring - and they all shift perfectly and quietly. And a work friend bought a very high end custom road frame recently. He originally was going to get a double, but after thinking about it and realizing that he would like to take the bike the Europe at some point and ride in the (big and steep) mountains, he put a triple on the bike. (And before your LBS says something about a big "guy's" frame for that example, the guy I am talking about is small - maybe a little bit taller than me - I'm 5'5" - and has a small bike frame.)

I'd recommend not going with the double if you have any concerns about the range of gearing.

--- Denise

[Pedal Wench]

Are you sure about that 50/30? Sounds like an awfully big jump - could it be a 50/34? That's much more common.

[Adventure Girl]

Are you sure about that 50/30? Sounds like an awfully big jump - could it be a 50/34? That's much more common.

And will your front derailleur be able to jump 20 teeth? That's a lot! I agree. 50/34 is much more common. What cassette would you run? 12/25?