In Praise of Lightweight Bikes

[simon.r]

I've recently started riding a bike which is a bout 10lbs lighter than my previous regular ride. Coincidentally I'm about 10lbs heavier than I was a few months ago

It doesn't make sense, but I am definitely faster (about 2mph on average) on the lighter bike than the heavier bike, despite the combined weight of rider and bike being about the same. The bikes have similar geometry, tyres etc.

So why am I faster on the lighter bike?

 

[Globalti]

Maybe it has a stiffer frame and transmits your energy to the rear wheel more efficiently.

Not 30 minutes ago I jumped off my 2006 Roubaix onto my neighbour's brand-new Orbea and was really surprised at how much better it climbs and accelerates, probably because carbon frame design has moved on so much in 7 years.

 

[simon.r]

That makes sense.

 

[biggs682]

mine over matter maybe

 

[simon.r]

mine over matter maybe

I've wondered if there's an element of that, but however much the mind wants to be faster the legs seem to say no!

 

[Shut Up Legs]

Perhaps the 10lbs is partly more muscle mass? My weight hasn't changed much over the last several years, but my legs are definitely stronger every year, so I'm reasonably sure I've just replaced some fat with muscle.

 

[Globalti]

Definitely.

 

[raindog]

You haven't mentioned the wheels, but if they're better quality that'll make a massive difference too.
As Globalti says, the big advantage is when climbing - you can really feel the difference then.

 

[Boris Bajic]

I can be the control group in this empirical exercise: I'm fat and my bikes are heavy.

I'm no faster than I ever was, which wasn't fast even then and is now even less so. This is a constant, although at times a variable one.

All data are given in kilogrammes and Miles per Hour or the tangential difference between the square of the two lowest results.

All variables can be calculated and compared with the above data to lend credence and credibility to the conclusions of any associated study.

I make no charge for the above data and do not even request a mention in the appendix of any published paper.

I hope I have helped but I fear that may not be the case.

 

[jdtate101]

Perhaps most of the extra 10lb weight is rotational weight in the wheels which would make a huge difference to climbing and accelerating???

 

[deptfordmarmoset]

Like jdtate and raindog my first thought was the rotational mass of the wheels making much of the difference.

 

[Cycleops]

I think it's the 'feelgood' factor, you have been uplifted by your new steed!

 

[nickyboy]

Reducing your rotating mass with a balancing increase in body weight will reduce the force required to accelerate

It will not have any effect on the force require to overcome gravity when climbing. Unfortunately, for that, a kg is a kg is a kg

So for sure you will be able to accelerate more quickly, it's probably better able to transfer the force you apply and a bit of feelgood....so it's all good

 

[bigjim]

http://yarchive.net/bike/rotating_mass.html

 

[Mr Haematocrit]

Im faster on my heaviest bike, but climb better on my lighter bike