10 pounds of weight lost adds 1mph to your speed?

[simmi]

Is this true? I totally disregarded this first time I read it but have since read it again so am wondering If there is something in it.
I weigh around 200lb and average between 15 and 16mph.
If I was to reduce my weight to 170 would I then average between 18 and 19mph with no increase in effort?
This can't be right can it?
Sorry about all the questions at the moment, As my wife likes to tell me I am an obsessive, and cycling is my new obsession.

 

[Cycleops]

Might just be true. If you think about it the weight loss means you'll be pushing along a lesser load so a speed increase does sound logical.

 

[MacB]

Yep, if you lose weight and maintain power then your power to weight ratio improves...what that translates to in the real world I haven't the foggiest and I'd imagine there's a whole host of variables to consider.

 

[zizou]

Weight loss aids climbing ability as the power to weight ratio is what is important here but that is much less of an issue on the flat where total power is the key.

So unless your route was very hilly then a gain of 3 or 4 mph is not going to happen just based on weight loss.

 

[shouldbeinbed]

if theres less of you do you go down hills comensurately slower? as there's less for gravity to drag on

 

[400bhp]

No.

Too many factors at play which weight is one of them. Arguably lost weight is a broadly a consequence of training harder, so is it the lost weight that is the driver or the improvement in fitness?

I've lost about 16-18 pounds in the last 12 months. It is one of the things that has made me faster (and what and when is faster by the way?) but my increased fitness is the driver.

 

[Mr Haematocrit]

I weigh 129lb and can comfortably do the speeds you mention, but it is my fitness that permits me to to do this..
But equally if your counting power to weight ratio, you also have to consider the weight of the bike, not just yourself.

 

[dan_bo]

and don't forget- if you achieve zero mass you should be able to do 186,282 miles per second!

 

[MrJamie]

IMHO its a nonsense statistic, weight hardly makes any difference on the flat while cycling. I've ridden a 10 mile circular route (ie. no elevation loss/gain or wind adv.) averaging over 17.5mph and weighing 19 stone, on a heavy 700c hardtail. I could probably lose 60 pounds, but I dont think theres any chance id be sustaining 23.5mph on a hardtail, although i might get some gain. Also 6mph between 20 and 26 is much bigger than 10 to 16, because of how wind resistance scales. From personal experience it makes a huge difference on hills though and is worth losing weight for that.

 

[MattHB]

It would be more accurate to suggest that the amount of power output compared to the weight of the rider could lead to an increase in speed.

Power to weight ratio is everything.

 

[400bhp]

It would be more accurate to suggest that the amount of power output compared to the weight of the rider could lead to an increase in speed.

Power to weight ratio is everything.

Only when there is a material force (gravity) acting against you.

 

[Sittingduck]

If you get lighter, you will likely become faster but a 1mph gain for 10lbs is way too optimistic (IMHO). I have increased my overall rolling avg by around 1.5 - 2 mph in the past 12 months, although I climb considerably faster than I used to. I dropped way more than 10lbs before getting results, however.

 

[Boon 51]

So where are we in the mathmatics of this thread when a 10st unfit bloke rides against a 14st fit bloke.. who would be the faster..

 

[MattHB]

Only when there is a material force (gravity) acting against you.

I was really meaning for hill climbing

This is a really interesting article that explains things. Particularly in respect to hill climbing.

http://wattbike.com/uk/guide/using_the_wattbike/power_to_weight_ratio

Only when there is a material force (gravity) acting against you.

I was really meaning for hill climbing

So where are we in the mathmatics of this thread when a 10st unfit bloke rides against a 14st fit bloke.. who would be the faster..

Again we could look at power to weight. A fit guy can likely put out much more power, and certainly for longer than the unfit guy.

 

[Tigerbiten]

In rolling terrain, around 1,000' climbing in 20-25 miles, loading around 20-25lb shopping into my trailer slows me down by about 1 mph.