Why do my knees hurt when cycling? And then suddenly not hurt...?

Thanks for the comments... * My seat is significantly higher than it was following another AskMeFi. I can't recall if my legs end up straight, but the saddle is now high enough that I can't touch the ground with my arse on the saddle and the bike upright. That made it a hell of a lot easier on my back. * I honestly don't recall if my bike is a Mountain or Hybrid but my wife swears she bullied me into buying a hybrid. But... * It's always had what I would call road tyres on it - wide and smooth with tread cut into it instead of knobbly. SUV tyres, not Land Rover ones. :) * 70-90 RPM sounds bloody high, and I'm definitely nowhere near that rate. I'm not actually sure I'd be able to manage that sort of speed. * I know my structure is buggered up, so it's quite possible my knees go out rather than up and down.

Decimask: That depends on how high the bottom bracket is on the bike. Whether you can touch the ground from the saddle is a function of bike design, not whether you've got the saddle too high or not.

http://ask.metafilter.com/210565/Why-do-my-knees-hurt-when-cycling-And-then-suddenly-not-hurt#3036848 I can't recall if my legs end up straight, but the saddle is now high enough that I can't touch the ground with my arse on the saddle and the bike upright. That's too high. (I'm also an overweight cyclist) Lower it a bit. The other comments about cadence are solid though. It took me a while to get used to the idea, but it really is all about cadence. When you change gears, find the gear combination that lets you keep a steady pace.

Fellow overweight cyclist here! The general advice about seat height and adjusting your cadence is great. However! While I know from personal experience that spinning at a good, knee-friendly cadence can feel really silly and wrong ("Shouldn't there be more resistance from the pedals? Shouldn't I be working harder? And I'll bet I look ridiculous pedaling so fast and furiously!") and takes some time to get used to, that doesn't mean you have to push yourself to get to 90 RPM. 90 RPM may be the ideal cadence for a fit cyclist, but it's not what those of us who aren't in that category need to aim for. Just start out with a higher cadence than you're currently using--if that means going from 40 RPM to 50 RPM, so be it. Then as you start getting used to that, try adjusting it some more until you find a good balance. And it is all about balance for us. The same techniques and metrics that work for racers and other lighter, leaner riders don't necessarily work for us. The way I understand it, high gear/low cadence puts stress on the knees, and low gear/high cadence puts stress on the cardiovascular system. Racers often choose to put the bulk of the stress on their cardiovascular system because their bodies can handle it. My 260 lb ass? Not so much. My heartrate monitor would go nuts, and my doctor would be most cranky. So I try to find the balance between keeping my knees happy and not having a heart attack. You might also want to look at whether your knees are moving too much laterally--do they point outward or inward when you pedal? If so, that's putting more stress on your knees than proper straight-up-and-down form does, so try to maintain that form. If you find it too difficult to do so, you may need Knee Savers (or a similar product) to adjust your pedal position slightly. A good fit from a good bike shop can help a lot, too. You might also want to check out the Clydesdales/Athenas forum at BikeForums.net. That's what male & female riders over a certain weight class are called, and there are a lot of us! I've found it helpful to be able to talk to others about the stuff the leaner and lighter riders don't necessarily have to deal with. Take care of yourself, but do keep going! I went from sheer terror of getting on the bike to short, flat, 3-mile rides like you're doing to 20- 30-mile weekend rides, some with hills I would have previously considered literally impossible to ride up. There is a joke in the cycling world that "it never gets easier, you only go faster," but it really does get easier, more quickly than you'd imagine if you keep at it.

Those higher RPMs quoted should be easier for you, because you should be in an easier gear to compensate. Struggling up hills in too high of a gear might seem like a better workout, but if you drop to a much easier gear you'll feel much better and burn the same amount of energy in the end. Low and slow is how I take my hills.

You need to adjust your saddle height.

Take your bike to a good shop and get fitted properly. Simply adjusting the seat isn't enough. I had all manners of achy this and hurting that until I finally got a proper fitment. It's even a possibility that the entire bike itself is sized wrong for you (it sounds like it might be slightly too big). This is exactly why you should stay away from WalMart bikes and go to a reputable shop that'll get you fitted the way you need to be.

Have you gone into a bike shop for a proper fitting? I was a pretty regular bike commuter and after awhile decided to try a hybrid. I ended up not liking it for a number of reasons but I also felt pretty good on it with minor adjustments but halfway through my regular commute, my knees would be screaming. I took it back in and asked for a fitting (my bike shop has two kinds, a basic fitting and a more intense one where they swap out seats, handlebars, etc., and dial everything in). But the basic fitting was enough to stop the knee pain. I ended up returning the bike because, it turns out, I like to commute on a road bike, not a hybrid. Secondly, when you're at the bike shop, talk to them about your gearing and the trouble you are having. They may have some tips for you for using your gearing optimally or they may look at your setup and recommend bigger or smaller chain rings. Also, don't worry about having to stop halfway up a hill. Eventually, you'll make it!

Also, if you're just starting out cycling then there's no shame whatsoever in stopping on the way up a hill when you run out of puff! Your body needs a bit of time to adjust to the new demands you're putting on it. If you keep track over time you should find that the distance you can go without stopping increases. How quickly depends on the individual...