New Build - Gearing Decisions

lewishamilton

I know this comes up every so often but wanted your opinion.
I'm building myself a carbon bike (not specifically for racing although I have done one or two triathlons. I'll use it as my summer bike and also anytime the roads are clean and dry).

I currently have a compact 50/34 12-25 cassette, which is ok, but I would prefer to have a gear or two more to prevent me spinning out at high speeds.

I'm getting a Sram groupset and have the option of 50/34 or 53/39 and cassettes 11-23, 11-25, 12-25, 12-27.

I was thinking about getting a 53/39 with 12-27 cassette OR 53/39 & 11-23?

Am I being really naive, or is it much of a much (I've looked at the sheldon calculator and it may as well be in arabic).
Also, can I run a short cage with the 53/39?

Wheelspinner

Should be fine with short cage derailleur with any of those cassettes.

You'd be best running an 11-25 with your existing 50/34 overall. That will give you an almost 9% longer top gear than you already have, but keep your low range advantage.

Trying to drive a 53/11 is something pros do downhill. Even 53/12 is damned hard work unless you are on the downhill side of an Alp.

Monty Dog

And the point of asking the same question on both here and Buying Advice is?

lewishamilton

Was offered the groupset yesterday and am picking it up tomorrow. I posted in both forums to hedge my bets and hopefully get more advice...I also thought the topic fell under both categories