Originally Posted by
cwcaesar
I have a couple of monster hills near where I live. (Monsters to me, anyway.) My hill climbing gear is 39x27, and one one of these hills I can only manage a cadence in the low 30s for a certain stretch. It gets to about 18% grade for 80 to 100 meters. Most of this hill I can usually get a cadence aroung 40. This particular hill is not quite a mile in length, but it absolutely kills me. As soon as I get past this, I have miles and miles of great cycling roads, so I would love to be able to tackle this hill more easily.
I looked at the online calculators and for the same climbing speed, I would only gain about 5 or 6 rpm if I switched to a compact crank with a 34 tooth ring. Is this enough of a difference to worry about? Would I pick up some speed doe to the easier gear?
If I did get the smaller cranks, should I hang on to the larger ones incase they were needed down the road? Or just sell them to offset the cost?
I know losing weight would still be the best remedy, but I just live in a very hilly section of the country. I don't want to hurt my knees from mashing on the pedals at too low of a cadence. What would you all recommend?
You want to put your muscles to work and at some point slow cadence is just part of it, but too low a cadence will strain your knees more than your muscles, and eventually slow your process to fitness goals.
Cadence of 30-40 is just too low.
Need the right tool for the job: that's a 11-34 or 12-34 cassette, a long cage RD, and a compact crank (50-34). I'd say to do it in steps, first change the cassette and RD, but since most likely you'll need a new chain, might as well change the crankset to 50-34 and be done with it in one swoop.
Ratio spacing mentioned is overrated IMO, range is the issue and compacts give you as much range as you'll possibly need. 50-11 or 50-12 gives you plenty of flat/downhill terrain speed (downhill, bodyweight will make you gain speed faster than any spinning so unlikely to outspun 50-12 or 50-11 unless you turn into a downhill demon).
Unlikely to outgrow the set up: If fitness improves to the point that the 34-32-30 cogs stop being used (with cadences 60 and above) you simply change the rear cassette back to the 11-27 you're currently using (no need to do it, just noting that it'll work fine with the long cage RD).
Good luck