# How much does seven pounds matter?



## Nick09 (Aug 1, 2009)

Okay, I know a 19 pound bike is not worthy of this forum, but, I had a question of how much of a difference there will be between my old bike and new bike. Right now, I ride a '82 Peugeot which weighs in at about 26.5 pounds. I am picking up a new bike, a Fuji Roubaix ACR2.0, which has a claimed weight of about 19.5 pounds. I am heading off to Clemson for school this fall, and I am not sure what it is like biking there, but it seems to be fairly hilly driving around. How much of a difference will the 7 pound loss make, if any?


Thanks in advance


----------



## Oxtox (Aug 16, 2006)

7 lbs is a fairly significant wieght loss. the bike should feel more responsive.

are you asking us to actually quantify the difference in performance for you?

that's not gonna happen.


----------



## Nick09 (Aug 1, 2009)

no, not quantify, just if there is a significant difference, a small one, or just an imaginary one... It may actually be around a 8-10 pound loss, just found out the scale was off a little...


----------



## Mapei (Feb 3, 2004)

Anything over a four pound difference you will notice instantly. Going from a 26 pound bike to a 19 pound one is like going from a Prius to a Porsche. You will break into a grin from the moment you throw your leg over the bike, because even _that _will be easier and more enjoyable. When you begin to pedal, you'll break out in laughter..


----------



## raymonda (Jan 31, 2007)

Usually I would say that anyone is better off losing body weight than bike weight but consider you would be going from a boat anchor to a bike, pull the trigger and buy the new bike. It will improve your ride on a number of levels, not only the static weight but rotational as well. The new wheels should be significantly lighter and thus contribute even further to the perceived weight loss, which may be closer to 10lbs or so.


----------



## Nick09 (Aug 1, 2009)

:thumbsup:


raymonda said:


> Usually I would say that anyone is better off losing body weight than bike weight but consider you would be going from a boat anchor to a bike, pull the trigger and buy the new bike..



Haha. I already bought the bike  Comes in Thursday. I bought it more for the purposes of possibly getting on Clemson's cycling team, but the weight savings sound like they will be much enjoyed! And I am 6' 2" and 155.8 lbs. With at most 7-8% body fat (haven't taken it in a while. Last time it was around 7.5). I don't think I can afford to loose much more, as I am a baseball player by nature, and coaches don't like to put stick figures on the field. The bike is the only thing that can loose the weight at this point. Unfortunately, my wallet cannot handle much more than a 19 lb. 1,600 dollar ride.  Maybe in a few years I will be graced with carbon


----------



## Fixed (May 12, 2005)

*numbers*

With these assumptions, dropping 7 pounds would get you up a 10 km hill 54 seconds faster. Riding by yourself, not a big deal. On the tail end of a road race, that's HUGE.

http://www.analyticcycling.com/ForcesLessWeight_Page.html


<TABLE cellSpacing=5 cellPadding=0 width="50%"><CAPTION>*Benefit From Less Weight*
</CAPTION><TBODY><TR><TD align=left>*This Much Less Weight*</TD><TD align=right>3.175</TD><TD align=left>_kg_</TD></TR><TR><TD align=left>*Over This Distance*</TD><TD align=right>10000</TD><TD align=left>_meters_</TD></TR><TR><TD align=left>*On Hill of Slope*</TD><TD align=right>0.05</TD><TD align=left>_Decimal_</TD></TR><TR><TD align=left>*Faster by*</TD><TD align=right>54.80</TD><TD align=left>_s_</TD></TR><TR><TD align=left>*Ahead by*</TD><TD align=right>307.58</TD><TD align=left>_m_</TD></TR><TR><TD align=left>*Frontal Area*</TD><TD align=right>0.5</TD><TD align=left>_m^2_</TD></TR><TR><TD align=left>*Coefficient Wind Drag*</TD><TD align=right>0.5</TD><TD align=left>_Dimensionless_</TD></TR><TR><TD align=left>*Air Density*</TD><TD align=right>1.226</TD><TD align=left>_kg/m^3_</TD></TR><TR><TD align=left>*Weight Rider & Bike*</TD><TD align=right>75</TD><TD align=left>_kg_</TD></TR><TR><TD align=left>*Rolling Coefficient*</TD><TD align=right>0.004</TD><TD align=left>_Dimensionless_</TD></TR><TR><TD align=left>*Power*</TD><TD align=right>250</TD><TD align=left>_watts_</TD></TR></TBODY></TABLE>


----------



## TomBrooklyn (Mar 15, 2008)

Nick09 said:


> I know a 19 pound bike is not worthy of this forum....And I am 6' 2" and 155.8 lbs.


 Your bike is not worthy of this forum? My road bike weighs about 38 lbs* at the moment with whatever is in the trunk, the lock, but sans water bottle, and I haven't felt my bike is unworthy of this forum. And I wouldn't bother noting my weight in tenths because I can add two pounds swallowing a bottle of Gatorade or drop two by taking a crap or working up a good sweat. 


*Weighed one wheel at a time and summed. I can't pick the bike up on my scale as it only goes to 300 lbs. My bike sports a rack, trunk, lock, and lights etc. as I use it primarily for transportation, although exercise and recreation are significant side benefits.


----------



## purdyd (Jun 18, 2010)

Nick09 said:


> no, not quantify, just if there is a significant difference, a small one, or just an imaginary one... It may actually be around a 8-10 pound loss, just found out the scale was off a little...


on a steep climb where wind resistance is neglible it will save you 3.5 to 4.5%

on the flats, probably nothing

you will accelerate 3.5 to 4.5% faster

you will not coast as fast or as long


----------

