Originally Posted by
cyccommute
You said “big bumps” in addition to downshifts. In my experience, downshifts aren’t where chain suck occurs. It’s on up shifts where the rear derailer doesn’t have enough tension to pull the chain off a damaged tooth…most commonly on the inner ring. “Dropping the chain on downshifts” is a different beast altogether and is usually due to poor derailer setup.
This is a large part of the problem with mountain bikes. They are set up for some sort of track or short distance riding. I use them over 10s to 100s of miles over terrain that is usually all up or all down with grinding uphills with little front shifting and fast downhills with little front shifting on the downhill side. The thing that a triple gives
me is the ability to climb
and the ability to actually pedal when gravity takes over. I don’t have to coast because I’ve run out of gearing on the downhill side.
Here’s a comparison of a modern
34/11-50 12 speed 1X to my ancient 44/32/20 11-40 10 speed 3x. The 1x spins out at around 24 mph. I can still pedal for another 6 mph. That comes in handy for rides
like this one where I hit a high speed of 35mph and had about 15 miles of pavement to ride before I could get off on to the dirt (on this ride there was about 5 miles of riding railroad ties which I wouldn’t suggest
)
In answer to
efriis@mac.com question, I do hate to say that triples are a part of history now. They really shouldn’t be. Not all bicycling nor all mountain biking is racing.
If I spin out the 34/10 on my XC bike, I'm likely over-biked for the ride anyway and should be on my 2x11 gravel bike anyway. Also my XC bike is a 10-50, once you account for 29" wheels, the 90 rpm speed becomes 27 mph vs the 31 on your triple. The 90 rpm cadence is slightly above 5 mph on the 34/50.
Massive climbing and descending on long rides are not foreign to me...I live and mostly ride in the mountains and my "flat rides" are still 75'/mile. Especially once we get into summer and the snow melts off the higher mountains, it's not uncommon to do 1 hour+ long climbs followed by 30 minute descents. My XC bike isn't purely for racing and my other MTB has never even been raced in its existence, so I think the 1x12 drivetrain is perfectly suitable for recreational riding as well.
I will clarify that my opinion of mtb'ing has changed as the bikes have become more capable. My most current XC bike has 120mm full suspension, dropper post, 180mm discs, etc...basically a waste of its capabilities to just slog on a fire road or paved road IMO. It's still fairly light/fast and a very efficient peddler, but my gravel bike is even faster/lighter for that sort of thing. Maybe a controversial opinion on my part, but that 2x11 gravel bike is just as dirt capable as any of the older XC MTBs. I guess some people may want even lower, but I've been fine with a 31-40 low gear up big "HC" Sierra climbs.