in a couple weeks ill be getting my bike ready for an everest. I picked up a wolftooth road link and am planning on borrowing my buddies 11-42 cross cassette. my calculations show it working. I want all the help I can get, so that should work for me! if not, ill be getting a 34!

---

Ask me how much I love my Kiwami LD Aero Trisuit

Yes. This is simply a ratio of teeth, so if you're saying for example 1:1.21 for 34T front, 28T rear, then it's 1:>1 because the front is bigger than the back. 1:1 will occur when they are the same size and >1:1 will occur when the rear is larger than the front.

better to erxpress it as chainring/sprocket in my opinion. So for example using a 34T chainring:
Typical 11-28 cassette = 34/28 = 1.21
32T largest sprocket = 34/32 = 1.06
34T largest sprocket = 34/34 = 1.00
If your derailleur can handle say a 36T sprocket = 34/36 = 0.94

I used a triple equipped Specialized Tricross when I started cycling 9 years ago. It came with a 30T smallest chainring and an 11-32T cassette (MTB derailleur). That was about 0.94 too and allowed me climb some pretty steep gradients (15%+) when I was a bit heavier and a lot less fit than I am now. I didn't go very fast, but I could keep the pedals turning.

I disagree, on pretty much points!
Three main things limit your ability to climb.

1. Ability to turn the pedals (Adequate gearing solves this)
2. Ability to maintain grip at the back wheel (I've only had this problem at >15% on country road covered in wet leaves and moss)
3. Ability to balance if you can't maintain sufficient forward speed. (Gearing does not help here)

I can only see ability to keep the front wheel down being relevant on absurdly steep climbs over 25% and if you're trying to stay in the saddle.

Really for an endurance challenge, none of these is likely the issue. If I was doing a massive day of climbing, I'd want the option of a really small gear for two reasons:

1. I could keep the cadence up on steep gradients and thus reduce pedal force for the same power. While I like grinding up climbs, my knees tend to complain after a few hours.
2. Towards the end, if I was really suffering a bail-out gear offers the ability to get to the end albeit at a crawl.

Your assumption that it would take someone days to Everest if they need 30/36 gearing, neglects the probability that they simply want to allow a higehr cadence, not a lower power. if cadence goes up as the gear ratio goes down, speed can remain constant, for example:

A cadence of 65rpm with 34/28 gearing will produce the exact same speed as a cadence of 95rpm with 30/36 gearing (both are about 79rpm at the back wheel).
Power will be essentially the same aside from any differences in the drive train.

Finally a your suggestion that a shallower gradient would not require such small gear ratios is obviously true but neglects the fact that it would make the challenge harder in other respects. The total work that needs to be done will increase since both aerodynamic drag and rolling resistance will be greater for the same rate of climb, and rate of climb is the entire point. If I was to do an Everest attempt I'd probably look for a slope with gradients in the 7-11% range.