I feel like some people take it too serious. They will spend $ to save grams. Im not totally sure but Im pretty sure 200 grams isnt the difference of winning or not. I guess every little bit can technically make you faster but on the otherside (great rhcp song) the heavier the bike more momentum it has to it wont loose as much speed as quick and will go faster on the downhills. Im not trying to insult or pick on you if you try to save weight like that but I just would like to hear why try to save such little amounts? I can see replacing a tora 302 with a solid carbon fork to save 3.5 pounds (as I did) or trying to save a pound but why so little amounts? I guess after a while it could add up to a significant amount but then agian, would a pound make the difference? Rider weight would be the biggest factor then. It seems that since Im 120 pounds and most people I race against are 150+ on 23 pound bikes, the fact that mine was 31 pounds seems totally unimportant since I still have a 21 pound advantage.

i think you hit it on the nail when you said "after a while it could add up". After a while it adds up.

i guess. But If there is one last thing you can upgrade, and upgrading it sheds say 200 grams wouldnt it then be pointless?

To an extent you're right. But I think wheels, tires, pedals, and cranks (Everything that rotates) are the most important to be as light as possible. Rotating weight counts way more than the bike's static weight (Eg. frame, bars, fork, etc.).

Unsprung weight is more important than rotating weight IMO. Wheels are obviously important because they're both, but in terms of handling, a weight savings on the fork (or the lowers anyway) or shock (outboard half anyway) is going to yield better performance gains than lighter cranks or pedals, gram for gram, particularly since the latter don't particularly raise the center of mass.

Fat people can lose grams pretty cheap.

i have been wondering...

is a person that weighs 150lbs on a 35lb bike the same as someone that weighs 165lbs on a 20lb bike? how does that work?

Ok. The rotating weight thing makes since. and I was just saying that my weight plus my bike < the weight of a light bike plus a larger guy.

I would think $500 for lessons from a pro or something like that would help you way more than $500 in upgrade parts to make the bike a few pounds lighter.

I just started into MTBing, though, so maybe I'm wrong.

I'm not sure where you would sign up for MTB lessons.

Surely someone offers MTB lessons.

EDIT: Ok, Yahoo shows TONS of results if I search "mountain bike lessons." Clicking on many of them immediately show the lessons being given by a trained pro, etc, so I'm sure you can find some quality ones even if most of them are BS.

Hmmmmmm...I think I'll look into taking a few lessons. That would be fun. What if you wind up with some fat inbred hilbilly on a Next? Wonder if I could get my money back.

A fat inbred hillbilly will probably just drive his Chevy 4X4 up the trail, so no need to worry about the Next. On the plus side, you probably will learn to be faster with him chasing behind you.

Whether or not you get your money back depends on if you can beat him, Roscoe, and Skinny Pete at a frog giggin' contest down by the ol' mill pond and then use your huntin' dawg to flush out more coons than them for the winners victory stew.

You're hittin' close to home son.........

To answer your question in my opinion............."Only to posers!"

How so???

This is a question I've wondered about. I'm guessing that, assuming both riders have the same muscle mass percentage, the 165/20 rider will have the advantage. It makes sense to me that your muscles are already using energy to propel themselves along with everything else, and the bigger rider will have more muscle mass to do that with, so it would even out until you bring the weight of the bike into it.

I'm sure it's much more complex than this, and I'd like to see an answer by someone with real knowledge on this.

Nothing in there has anything to do with the weight of the rider.

Um, what is the "m" then, if not mass? The mass of bike + rider?

The equation makes my head spin even though I was able to deduce most of it.

Couldn't find where you got the equation, but I did find this.
Bicycle Performance

The crux of the question is how big of a bag of dope is each mountain biker carrying?

Did someone say dope**********!!!!!

I've always seen these arguments and wondered. I know that my weight is considerably more than my bike (200lbs with a bike in the mid 30s), so me losing 15 pounds seems like it would be way more of a contributor than dropping a few pounds off my bike, but I don't think so. I say this because the bike is an extension of the body; an outside tool.

By being like this I think the effect of the weight is multiplied, especially noticeable in technical parts of trails. Think of it like golf or baseball. Add a pound to the club or bat and it'll be a huge difference (the physics of swinging something makes the effect more dramatic than riding, but same theory).

Like when people who are heavier say 'try running with a 50lb backpack on,' they're incorrect. It's not the same. Their bodies have the weight incorporated and distributed in a more 'natural' way.

With the heavy rider with light bike versus lighter guy with a heavier bike, I think the advantage is to the heavy rider. There is less of an effect from the weight of the bike, and also when standing up he has 15lbs extra to drive the pedal down with.

At least that's how things work in my own little world... Strippers are also very nice people in said world.

Depends on how close to the border they are.

You must be carrying a few hundred grams of $1's then...

Well... I was.