Does anyone know what influences the way a bike climbs besides the weight of the bike? I have ridden some really light and stiff bikes that climb worse than others that weigh 2-3 pounds more, and I am curious what those differences are and what bikes you think are the best climbers?

Fit matters a lot. If they bike doesn't fit you well, it is hard to get a rhythm going when climbing. On a flat road, you just need to worry about side-to-side balance. When climbing, especially when standing, fore-aft balance has a big impact on your performance.

The stiffness of the rear triangle and bottom bracket area makes a huge difference. A stiff bike feels like all your power is going right into the road. A softer bike feels like you are pedaling on soft asphalt and your energy is being eaten by the road. Bike frame design is very tricky. Some get it right, and some don't. Weight is not nearly as important as power transfer. Power transfer is an issue all the time, even on the flat.

some non-frame potentials: gearing, wheel weight (rotational weight on climbs is tres important).

i hear that r3's are amazing.

It's not the bike, dude. It's you that makes the difference.

For me, I like very stiff bikes. I have a Cervelo Soloist Team and a Trek Madone. They are both very stiff for me (145 lbs)

The reach to the bar tops is important so you can get a good pull on it while seated. Get back in the saddle, drop your elbows, and keep the bike from shooting out from under you by pulling on the bar tops. If the bars are too close, this feels really awkward. Too far away actually feels pretty nice in this position, but ruins every other part of your fit.

I haven't fully quantified it yet, but I've got another climbing position for moderately steep stuff (10% or so) where I can sit up really high, roll my hips forward a bit, and it suddenly feels like I'm using completely fresh muscles all of a sudden. I get to do this for about 1 minute, and then it's over, back to being tired again.

Frame stiffness is a personal preference thing.

If anyone saw this guy on the final stage of the Paris-Nice race on Versus TV on Sunday, now that is how to climb! https://www.velonews.com/race/int/articles/11902.0.html

Yes, very impressive display of climbing. Kind of reminded me of Armstrong in the out-of-the-saddle power drive.

Some cyclists recently recommended a climbing position where you grab the bars along the top, right on either side of the stem, and visualize driving your butt straight down onto the saddle in order to stabilize your hips & lower core. I've never quite been able to figure out if I'm doing it right, but my wife now swears by it.

Yeah, it's something like that. It's a very strange feeling, and I can't replicate it all the time. It's like having 5 nitro power-ups in that Off-Road arcade game from the 80's. It doesn't last long for me.

+1

Otherwise, maybe a more relaxed, upright position so you can breath better, or a compact gearing setup...

Found some clips on YouTube.com.

https://www.youtube.com/watch?v=u61BF_9sZBE
https://www.youtube.com/watch?v=UEoHpxFgNDA

That's awesome. Thanks for digging those up.

Thanks.

There's actually more clips from other stages if follow the links. In any case, youtube.com is just amazing.

Love my R3 and I was never a climber, really still not. But the R3 is making all the difference in the world for me. I felt like I was pulling a trailer behind me on my Lemond.

Sweet videos! Those videos show him staying loose and flexible when climbing out of the saddle and his upper body became rigid once he was standing.

I use a variety of positions throughout the climb, depending on the length and type of hill. I tend to shift between positions slowly and I could probably learn to do it more often to stay powerful for longer stretches.

whenever i want to get pumped, esp for climbing, i watch this:
https://www.youtube.com/watch?v=DQDjqAkLUB0

That one is so evil with two unclippings.

Rotational weight on a climb doesn't hurt you any more than weight anywhere else. In fact, since rotational weight smooths out the speed fluctuations *slightly* it is actually better than weight somewhere else.