Originally Posted by furballi (Post 11009999)

A couple of trips to the bathroom.

Let's see...for an average 150 lbs cyclist, the difference in mass is about 2%. That my friend, is noise in the real world...unless you're doing a time trial.

Want more proof? Buy a cheap $5 speedometer. Put a 5 lbs bag of rice or bean in your backpack and go out for a ride. Come back and let us know if you lost more than 1/2 mph.

http://www.dealextreme.com/details.dx/sku.24075

Originally Posted by gsteinb (Post 11010893)

The difference between a 20lb bike and a 16lb bike is much more than weight. Everything on the lighter and more expensive bike is designed for better performance. Is it necessary? No. Is it nice? Yes. More reliable and responsive equipment certainly helps, perhaps more so with confidence than even in actual race day applications. That's just on the flats though. I lamented riding a rear 404 last week on a mountain climb due to a flat. That was only 5 ounces heavier than the wheel I wanted to ride.

Originally Posted by Grumpy McTrumpy (Post 11020063)

great. a pissing contest in high-school physics

Originally Posted by JohnDThompson (Post 11020531)

What difference does it make? Depends on how much you're being paid to ride it.

Originally Posted by travkat (Post 11020022)

This doesn't address the fact that you may indeed not lose the 1/2mph but you might be working harder (wattage) in order to maintain that speed.

Originally Posted by OhioBuckeye (Post 11009953)

I recently purchased a Trek 1.2 bike and it's spec'd at 20lbs I believe. I see bikes that are double in price and they can be down to 16.5 lbs.

How much difference does that make on a ride? If you've make a similar jump of dropping 3-4lbs of bike weight did it make a huge difference increasing you average speeds?

Thanks

OB

Originally Posted by donrhummy (Post 11020820)

An aluminum bike has a lot of flex (for example)

Originally Posted by Grumpy McTrumpy (Post 11020063)

great. a pissing contest in high-school physics

Originally Posted by SwingBlade (Post 11014262)

It is the relative technological gains as overall bike weight plummets that yields both real and perceived differences. With respect to comparing a 22 pound bike with a 15 pound bike, the meaningful differences are not so much related to weight savings as to the efficiencies resulting from the technological advantages and efficiencies inherent with successively lighter bikes. These efficiencies make a real difference in energy expenditure and endurance particularly with respect to climbs, which is why although speed gains are minimal, performance gains are often meaningful. The accompanying perceived gains of such technology, while perhaps not strictly quantifiable on a case-by-case basis, likely result in varying degrees of improvement in attitude and confidence.

Originally Posted by gregf83 (Post 11019861)

Nope. Any performance improvements while climbing are pretty much solely due to the weight loss. Better components may shift nicer and feel better but they won't make you faster up the hill.

Originally Posted by donrhummy (Post 11020820)

I've found the weight of a bike to be a very small difference, but the stiffness of a bike to be a HUGE difference, especially on climbs out of the saddle. An aluminum bike has a lot of flex (for example) but ride one of the top carbon fiber bikes and it'll literally leap forward on every pedal stroke - zero wasted watts.

Originally Posted by KiddSisko (Post 11033577)

Please. Under no circumstance will there ever be zero wasted watts. There are so many factors that add up to wasted energy. Body position (fit) and pedal stroke being two. A serious road cyclist can take years to develop an efficient pedal stroke. A "top carbon fiber" bike isn't going to magically cure the shoulder heaving Fred out there pedaling squares.

Originally Posted by Braden1550 (Post 11034783)

Every single joint in your leg, connection to you bike (shoes, pedals, hands, seat), and many parts of the bike (chain, cranks, pedals and pedal axles, bearings, wheel stiffness, frame stiffness, frame geometry, chainrings, cassettes, hubs and associated mechanisms, you name it) can each represent potentially wasted wattage.

Originally Posted by DScott (Post 11050253)

I <3 light bike threads!


[video]

Originally Posted by KiddSisko (Post 11050383)

Have you been drinking?