What would be the performance difference, if any, between using a regular crank and a 12-27 cassette for climbing or a compact crank with a 12-25 cassette? (Assuming the same front chainring configuration)
Has anyone switched and what are you thoughts on difference?
Thanks for the input.
With same chainrings, regular crank with 27 will provide easier climbing. Point of compact crank is to allow use of smaller chainrings (Regular 130mm BCD crank = 38 tooth smallest chainring, with compact 110 BCD, you can get 34 tooth (or maybe even smaller). If you don’t use smaller chainrings, there is no point in getting compact crank.
HH
For climbing 39 front 27 rear will be very similar to riding 34/23. In fact 1.44 vs 1.47 ratios. This means that you can go with a rear cassete of 23/11 and have much closer ratios. But if you want to climb very steep hills 34/25 will be easier for you than 39/27. With 34/27 you should be able to spin up the Everst - I find 34/25 way over geard.
Cost wise it is much cheaper to go 27 - and leave the front standard 53/39.
Top speed: if you have 50/11 it is faster than 53/12 but of course slower (obviously) than 53/11 which I doubt you could actaully push much.
I find that the front shifts much better when using 53/39 if I compare it with 50/34. If I shift from 50/25 in one go to 34/25 the chain falls off. My mechanic spent ages adjusting the system (FSA and Ultegra 10), but he can’t manage this specific shift - you might say who rides like this but I like to know my chain is always solid. However stupid I might be in a race.
Compaq crank - is it not called Hewlett-Packard cranks nowdays?
I prefer compact cranks.
The best way to figure it out is to run a gear calculator. It’s easiest to meadure it in gear inches for comparisons. eddie.
Where do you live and how much do you weigh?
Compaq merged with HP.
Remedy to that is the Third Eye Chainwatcher. I’ve never had a dropped chain since I put one on my ride.