Aerodynamics and the everyday cyclist

[Heltor Chasca]

Come on, HC, that's only heavy if you're five foot two...

Only 75mm out

I am designed to push wheelbarrows though and my ex FIL said he’d never start with me because my arms were thicker than legs. (Australian mentality) Instead he let me marry his daughter which was much worse than a fight with an angry bear.

 

[CXRAndy]

What about weight? I am heavy at 73kg. I will leave my lighter comrades behind on descents.

(They soon catch me up on the next hill though)

I think you have said this before.

YOU ARE NOT HEAVY

Im heavy at 98+ kg

I'll piss all over you free wheeling down hill.

panniers and baggy clothing will have a huge drag slowing you down.

 

[Heltor Chasca]

...I'll piss all over you free wheeling down hill....

Very niche, but not for me. Thanks for the offer though

 

[DCBassman]

I'll piss all over you free wheeling down hill.

Very niche, but not for me. Thanks for the offer though

Getting a bit open minded for an aerodynamics discussion!

HAve definitely benefitted on downhills from being porky, overtaking whilst freewheeling others who were really spinning it. Felt good!

 

[lane]

Tyre rolling resistance might have an impact.

 

[Fab Foodie]

Tyre rolling resistance might have an impact.

Minor.
Above pootlin’ speed, aerodynamics is everything regarding speed for any given person. This is why slipstreaming is so effective at maintaining higher speeds.

 

[Tigerbiten]

It's roughly around 15 mph that air resistance starts to get bigger than rolling resistance.
Good tyres and oil tends to lower rolling resistance.
The better your aerodynamic position is, the faster you can go.

YMMV ...........

 

[Shut Up Legs]

What about weight? I am heavy at 73kg. I will leave my lighter comrades behind on descents.

(They soon catch me up on the next hill though)

That's only heavy if you're relatively short. I'm 78kg, and am quite slim, because my height is just under 6'3" (190cm).

 

[PaulSB]

One possibility is wheels. I upgraded to carbon wheels a few months ago and have astonished by the benefits.

Descending is now 3-4 mph faster.

 

[Globalti]

Please tell us more about those wheels. Is it the fact that they are carbon or is it the shape of the rim?

Can you measure the increase in speed as, for example, higher recorded averages for the same route?

 

[CXRAndy]

Getting a bit open minded for an aerodynamics discussion!

HAve definitely benefitted on downhills from being porky, overtaking whilst freewheeling others who were really spinning it. Felt good!

Its always a short lived victory, unlike the suffering going uphill

 

[Illaveago]

You mentioned that it also happens when following other cyclists, which would suggest that unless they are all more aerodynamically efficient than you then you might have a problem. The fact that you mentioned that your rear hub is noisy, have you lifted the rear wheel and spun it to see how long it spins for ? The fact that you are carrying panniers will have an affect on drag and so will wearing jeans.

 

[SuperHans123]

What about weight? I am heavy at 73kg. I will leave my lighter comrades behind on descents.

(They soon catch me up on the next hill though)

Heavy?
Don't take the p*ss!!

 

[nickyboy]

If you're about the same weight overall, it can only be that he is pushing out more watts than you or his drag coefficient is less

I suspect it's a combination of the two. Panniers are well know to be extremely inefficient aerodynamically. On a 2.5% descent it's easy to keep pedalling so he was probably pushing the pedals a bit harder than you too

 

[Tigerbiten]

It's probably a lot of little things that make you slower.
Slightly more drag in the noisy bearing.
Stiff heavy puncture proof tyres have a high rolling resistance.
Panniers have an increased air resistance while a pannier bag is lower.
The higher you sit up, the more air resistance you generate.
Add all the little extra resistances together will add up.
Also if you're not as fit/strong as the person in front then it's harder to keep up.

Luck ...........