what is the difference between..
 

Someone who is "mashing" and someone who is spinning in the same gear?

Is it just the extra muscle that the spinner has that stops this damaging their knees?

Thanks

Daven

One is going uphill and the other is going downhill ?

I'm not sure I'm following you. Mashing refers to using a big gear with low cadence. Spinning is an easier gear with higher cadence. You really can do both in the same gear. If you are spinning (say 100 rpm) in an easy gear and wanted to mash, there isn't enough resistence to mash and you slow down. Often people refer to the two as different techniques to go the same speed.

If they're in the same gear, the difference is that the masher weighs twice what the spinner does, and is going half or a third as fast. You can't really compare.

One has a stiff tailwind, the other has a stiff headwind ?

Hmm, what I am trying to get at is that people are comfortable in different gears, what makes mashing for one person in a certain gear worse for the knees than for another person who is happy to spin in that gear?

I mean they must both have to push down on the pedals with the same force, but one person is happy to do it much faster. Does the extra muscle take strain off the knee?

EDIT: post changed after I replied !!

They aren't applying the same amount of force per stroke.

It's force x rpm.

The spinner is applying less force more often.

The other guy is trying to pop his knees.

:)

Ok, you are really asking about cadience. Theres a secret about it, that if you can spin like 100 rpm or more theres some power in there you would not have otherwise. Its a tradeoff of how to make power. N reps at a given force or 10xN reps at 1/10 the force. Its hard to describe, but you know the effect of a flywheel spinning at a high speed, and how its energy can be released, its using your legs in motion as a force instead of just the pushing force of the muscles at low speed. The ratio of slow twitch and fast twitch muscle you have will tell what works best for you.

I think what you're missing is that "mashing" implies "pushing hard". If the same person is able to "spin" in that same gear on the same terrain, then if they slow down and do it slowly, they're not really mashing. If I go pedal my single speed around at 5 mph on level ground, that's not mashing. If I get on a hill where I can only go up it at 5 mph, then I don't really have a choice of speeds, either, so spinning isn't an option.

I think that possibly you do not understand gearing/leverage.

Can you pick up 150 lbs? No? How about 50 lbs? If yes to the second but not the first, try lifting 150 lbs by a straight rope over a single pulley, then try it with a pulley block giving a 3 to 1 advantage.

Put another way, do you normally "Mash?' That is, pedal up hills at 30-50 revolutions per minute? Yes? Now force yourself to try it at 90rpm. Even if you can do it at 30-50, you will find that the wear at 90 is less on your knees. You might be able to do the lower rpm now, but when you get 20 years down the road, your knees will thank you.

Learning to spin requires some learning, it is worth it.

I think I get what you guys are saying! Either way I am starting to spin a lot more than I used to.

Thanks