Spinning up hill problem
 

I realize the optimal cadence to ride uphill is 90+rpm

I usually ride flats around 100-105: it just feels natural for me to spin realy fast

but once I hit the climbs, ah man, It goes to around 70-80. I drop to my 42 chainring and the biggest cog in the back and I am mashing

is this cause the grade is just pretty high? usually around 4%+ this happens. or maybe i am just unfit and have no strength whatsoever

A 4% grade would just be a moderate climb and shouldn't get you into trouble.
On the other hand a cadence of 70-80 on a climb is not bad, you might just need to get used to the lower cadence on that climb and as fitness improves you might be able to spin a bit faster.

Ok, ill tell u what man, I gotta use my 30x26 on the 28% grades near where I live lol now THAT's normal ;)

90 is a fast cadence for climbing. Most people use a significantly lower cadence. Why do you think that 90+ is optimal for you?

I'm a spinner too (100-105 rpm on flat terrain), but my cadence slows to 70-80 on hills. It happens.

because on the flats I always ride atleast 100rpm naturally

Never rode up a hill at 90rpm in my life. I don't even think it is desirable, if I tried to do that on a significant climb I'd be destroyed, my HR would go through the roof. If I have the gears to climb at >70 I'm a happy rider.

So how do the elite professional riders do it? is it just really strong leg power and/or EPO (well, of course, for most riders at the least)? I don't get when these people on forums or youtube say it is best to climb at 90+RPM when it is near impossible without years and years and years of training and/or EPO

It isn't about epo. It is about having power to burn.

fast cadences are excellent for the legs, they minimise muscle fatigue. But they are hard on the heart and lungs, they demand that you can cope with massive aerobic demands. This is no problem for the pros with their huge VO2 maxes. We are a different breed of cat. And even the pros don't really climb steep hills at > 90 rpms. Not many of them, anyway.

Reasonable article:

http://www.bikeradar.com/fitness/art...matters-16394/

In summary:

"The legs act as a more effective blood pumping system when the cadence is higher – if you hit a faster cadence the heart output increases [7]. For the same power output (200Watts as used by Gotshal, 1996) higher cadences make for better muscle blood flow, and in-line with reduced muscle strain data, it makes for better endurance. At 200 Watts (around 20mph) if you spin 100rpm your strain works out at just two Watts per rev, whereas at 60rpm your strain is over three Watts per rev."

"However, elites are known to pedal faster than beginners, and with more oomph on the down stroke of their pedal action [2]. The exact reason why pros get more force down through the pedals is not clear. But (unsurprisingly) it seems to be due to their muscles, which contain higher blood capillary density and the type of muscle fibres that can only really be built up through years of endurance training – not to mention hill climbing, combined with fast riding in groups that allows high speeds and low effort. This produces high pedalling power and the ability to spin fast."

..It's not really about VO2 Max at all - you can easily have surplus vo2m and be unable to spin at that speed. It's about the muscle system and providing it with optimal support. Most endurance cyclists will have a preponderance of slow twitch muscle fibres, and then they'll have have developed masses of extra blood vessels. This makes spinning a great metabolic payoff for them - they're playing to the (extremely non-typical) strengths of their muscle type. If they increase wattage per stroke - which is what happens when a lower cadence is used - then they'll engage fast twitch fibres, which they are low in and which don't "refuel" as well.

I think it's mostly because most non-pro riders are over-geared and don't have low enough gearing to spin up a hill. I can spin up a short <3m hill at 95-100rpm but that's because I'm putting out high power. Going up a local 15min hill at around 7% I don't have low enough gears to spin that high or I might try.

One difference between a hill (or indoor bike trainer) and the flats is the inertial load at the cranks is significantly lower for a hill so it feels quite different. Most people naturally select a lower natural cadence with a low inertial load. Yesterday I was pedaling with a stiff tailwind (very high inertial load). It felt like I was pedaling slowly but when I looked down my cadence was 105. Conversely, on a hill an 80-85 cadence 'feels' fast.

I may look into getting a new cassette and rings, probably just getting a whole new crankset, so I am not mashing 9-10% grades on my granny 30x26, I know cobo used a 32x36, that could be interesting

Interesting, so I guess the only reason that the inertial load matters is because one can not apply even power during the entire pedal stroke. So during the dead spots the pedals will slow down much more when going up hill compared to the flats and the natural thing to do is dropping the cadence going up hill.

Or perhaps it's much easier to apply even power around the stroke at a lower cadence.

So it's all about tactics between you and your opponents. On a multi-pass ride or race, if you have a higher aerobic limit you would do well to pedal a higher cadence than your opponents, hoping to have more in your legs on the final climb. You would also train that way. If you know your aerobic limit is lower and it's a mountain-top finish, you're screwed.

OTOH if it's a finish 30 miles after the last pass and you have a lower aerobic limit, you'd do well to pedal your favored rhythm and try to shelter until the last pass, then attack and see who comes with, so you'd practice your descending and flat skills. That's me. So you have to figure out your most efficient cadence for the amount of climbing to be done.

If less climbing, probably a slower cadence, even as low as 70 might be best. If a lot of climbing, then faster, whatever you find it takes to leave you with glycogen in your legs going over the last pass. You have to ride a lot and experiment. On short days, like just a one hour climb, you can pedal just a little more gear than you can continue to turn seated, then stand and accelerate when you slow. Then you'll be cooked, but maybe you can sit in the rest of the way.

Anyway, the optimal cadence to ride up hill is not 90+. It's whatever gets you to the top of the last hill the fastest. Train and experiment with different cadences.

As others have pointed out, many people will choose gearing to minimize steps between gears rather than to achieve some optimal climbing cadence. Which way to go will depend on the mix of climbing, flats, and descents. You're not going to choose the same gearing for STP and the Death Ride, even though STP has climbs.

Pro rider, Amgen Tour of California stage 1, 8600 ft of elevation

http://app.strava.com/activities/53898268

Cadence in 80 to 90 range, whether it's a flat or a hill.

Same guy, stage 2: still 80 to 90; drops into the 70's during a final segment with double-digit grades

http://app.strava.com/activities/54069310

A different guy, stage 1:

http://app.strava.com/activities/53899791

90-100 on flats, 80-100 on hills. Averaging 90 through the steep part of Cole Grade (9-11%. Most non-pro-riders here would either pedal out of the saddle or walk.)

Same guy, time trial stage:

http://app.strava.com/activities/54793795

100 rpm on all flats and all shorter hills. Drops to 75-80 on the killer 12% hill in the end. I'd guess that he is out of gears at this point. That would make his lowest gear on his time trial bike 39/27 or 39/28. Judging by his stage 2 track, he has 39/30 or 39/32 on the road bike.

This is a guy that averages 5.83 W/kg during his (nearly 1 hour long) time trial. If you can do 3 W/kg for an hour, your ideal lowest gear is proportionally lower: 39/58, or 34/51, or 30/45. You can see the problem.