Originally Posted by
bonsai171
Hi,
I'm currently running a 53/39t Shimano 105 5700 drivetrain on my road bike, and plan to do some serious climbing this year. I've done 14-15 % climbs with this gearing (mostly shorter climbs), but in this area, you can climb 100 ft for every 10 mi ridden. Would it be beneficial to go with a compact crankset?
Would it be possible without changing derailleurs/shifters? Got a 11-28 cassette in the rear.
Dave
It depends on how strong you are.
For reference: I regularly do climbs over 12% sustained and peaking between 15 and 20%. A particular climb I do at least once a week is 3km long, min gradient is 15% and max 20%. I'm running a 50/34t with a 11/32t cassette. I can climb them with this gearing, but I must admit that using the lowest gear I'm around 50rpm and 95% of my max bpm on the hardest parts. I'm seriously considering using a 11/34t cassette, although I'm not keen on the increased gaps between sprockets and have been holding back because of this, since such climbs, although frequent, are only a "short" portion of my rides.
I can do the same climbs using a 28 cassette, but my legs feel knackered afterwards since it forces me to either pedal standing up at a really slow cadence or ride at a higher speed which I find it difficult or impossible to sustain, especially in hot weather.
Sometimes I also use the 34-32 low gear on more modest climbs, maybe around 12%, when they are long and I feel my legs tired because I've been riding for long, or I've been riding hard.