I just bought my first tri bike (woohoo!). It comes with a 52/36 crankset and an 11-25 cassette. Should I replace the crankset with a compact 50/34? I understand the 50/34 is better suited for rolling hills (which are the types of races in my schedule), vs. the 52/36 for flats. Thanks for the advice! -- Pablo
You might try just swapping cassettes to an 12/25 or 12/27. It will get you very close to the same gear ratio as a 50/34 with an 11/25 cassette.
It's also a lot cheaper and easier to do.
You're basically looking for higher RPM at a lower speed (high cadence while climbing).
This is a great resource for figuring out which setup you want to run.
52x36 is a mid "compact" crank. A regular crank is 53x39. A 11x28 or 12x28 cassette should give you plenty of gearing unless you are racing Savageman and Lake Placid. However, I race with 50/34 and 12x27 cassette, and the extra gearing helped at Lake Placid.
Thanks for the advice. As it turns out, I have an 11-28 cassette. It sounds like between the 52/36 mid compact crank and the 11-28 cassette I should be good for rolling hills (Louisville, Raleigh)? -- Pablo
The way to find out is to go ride.
If you find yourself really wishing you had one more gear a lot in rolling hills type of rides, you can usually get another gear or two with a hardware change. I don't mean the Savageman course (everyone wants more gears) but what you ride most often.
Here's my setup:
TT Bike - 50/34 with 12/25 in the rear. In my low gear I'll spin out (100+ cadence) at 32.7 mph and when climbing in my high gear I can maintain 80 rpm at 12.7 mph.
Road Bike: - 50/34 with a 12/27. In my low gear I'll spin out at 32.7mph and when climbing in my high gear I can maintain 80 rpm at 11.6 mph.
As you can tell they're almost identical. My road bike is much lighter and a geared slightly better for climbing. My TT setup was for Mont Tremblant last year and I switched to compact (50/34) chainrings specifically for it. I like it so much I may just keep it a compact.
One thing to note, if your crankset is a 110 Bolt-center diameter (BCD) you should be able to just swap chainrings from a 52/36 to a 50/34 without actually having to change cranks. It's a lot cheaper. If it's a 130 BCD you'll need to replace the crank.
Hope that helps.
Or you just can go train harder.
And for my fixie: