Gear ratios and w/kg - Nate's list from #278

So Nate riddled off some numbers for chainring size and w/kg for mountain bikes last Thursday and it struck me.
I’ve been running a 34 x 46 eagle all season and I am only about 3.5 w/kg.
Am I crazy/stupid/ego driven/killing myself? or is the recommended 30-32 x 50 configuration he described where I should really be at?
I don’t really like spinning the 46 unless the trail is steep and I’ve been hammering for a while I figure if I reconfigured, I’d be sitting in the 4th or 5th cog anyway.
But i am fully willing to adapt if I think I can be more competitive. I certainly have room to improve in my midweek series.
Also, did anyone catch the science or source of Nate’s list?

The discussion is here

I think it largely depends on your terrain. If you live somewhere pancake flat, you probably don’t need the 50. I’m just a bit higher on the w/kg, but still a bit less than 4 and I use a 50 cassette on my XC bike as I’m in New England and we have a bunch of short punchy climbs that can be quite steep. However, on my trail bike I’m still on 11 speed so I only have the 42T and get by ok on that.

I think those chainring recommendations were opinion based not science. I don’t recall them quoting anything.

ETA: You could obviously change your chainring, not your cassette to get similar ratios as well (would be much cheaper if you want to try it out)

It depends on the trails where you ride. Do you have long climbs, or are they short and punchy? If the former, 32-50 would work better. If the latter, 34-46 may be fine (although my preference would still be for 32-50).

I think Nate’s recommendation is based on what works best assuming you’ll be riding longer climbs (like in Cape Epic, or Leadville).

Sorry, I forgot to qualify. Norther Utah, similar to the conditions they ride in Reno.

It also depends on the length of rides you are doing. For 1 hr races, you can probably power up a hill at 50-60 rpm just fine. But for Marathon XC (5-6 hrs +) the easier gearing + higher cadence helps to avoid fatigue.

I live in Colorado and do a lot of long rides with climbs. I really like the range of 32-50 for that.

This makes sense. I am probably not going to swap out the cassettes - I’m using that e*thirteen 46 and don’t want to have to mess with swapping those out, but a 30t chainring is probably a good kit option.
I think i did a 36/42 11-speed at 25 hrs of frog hollow last year and that seemed just fine to me for 175 miles and 18000 feet. But maybe I could’ve gotten another lap in with a better configuration.

Yesterday, I rode 23 miles and 3500 feet and figured that was just fine for 34/46. but it wasn’t a race.
My last race was 9 miles and 1550 feet and I suffered. So having a couple of chainrings in my kit to swap out is probably a good idea.

Yep - easier and cheaper to swap out a chain ring. You may also need an additional (shorter) chain.

Last year for Leadville, I swapped my 32 for a 30 and needed to remove a pair of links. The chain was a little too long and was “loose” in the 30-10 gear.

I’m back on the 32 now, as I find the 30-50 to be too low of a gear for technical singletrack. It’s so low that it makes it difficult to use a power pedal stroke to lift the front end and surge over a root or rock.

I don’t want to derail the thread but I’d be very interested in similar w/kg to gearing recommendations for road bikes, especially as someone contemplating European/mountain sportives next year (cv19 permitting, obviously).