bottle holder bolts for aerodynamics remove or leave in?



Aerodynamics

New Member
Jun 20, 2014
7
0
0
No idea to put this I'm wondering if its more aerodynamic to take the bottle holder bolts out of the frame or leave them in? Or take them out and perhaps cover them with something that wont create drag
 

dabac

Well-Known Member
Sep 16, 2003
2,298
288
83
52
It really doesn't make a measureable difference. Me, I prefer to leave them in.
 

Froze

Well-Known Member
Jul 13, 2004
4,711
756
113
NE Indiana
Those bolts won't cause any drag that would be measurable. Don't get all crazy with the aero ****, keep in mind since 1963 till 2013 the TDF average speed has only gone up 1.3 mph with all the lighter and aero bikes, tech, training, and doping. So now you figure out how much bolts will cost you in time!
 

CAMPYBOB

Well-Known Member
Sep 12, 2005
11,945
2,086
113
Cover them with tape...preferably tape with some sort of raised dot pattern or trip strips that will break up the boundary layer of air.

Doing so will save you .003 grams of drag and cut your 50 K ITT time by a theoretical 1.67 seconds.

This is the type of tape preferred by World ITT Champion, Tony Martin to cover his water bottle mounting screws:

 

Froze

Well-Known Member
Jul 13, 2004
4,711
756
113
NE Indiana
Originally Posted by CAMPYBOB
Cover them with tape...preferably tape with some sort of raised dot pattern or trip strips that will break up the boundary layer of air.

Doing so will save you .003 grams of drag and cut your 50 K ITT time by a theoretical 1.67 seconds.

This is the type of tape preferred by World ITT Champion, Tony Martin to cover his water bottle mounting screws:

Please show us wind tunnel testing to prove just by using that tape alone to cover water bottle mounting screws alone will save 1.67 seconds in a 50k race.
 

CAMPYBOB

Well-Known Member
Sep 12, 2005
11,945
2,086
113
That data is closely held at Freiburg University. I can say we use this same tape to plug the hex recesses found in the bolts of the stem cap. Good for another 0.056 seconds.
 

Froze

Well-Known Member
Jul 13, 2004
4,711
756
113
NE Indiana
So now I'm thinking, oh boy here we go, if covering those tiny bolts with that tape will save 1.67 seconds in a 50k race and some time with the stem cap covered too, which would mean if I covered the entire bike and my helmet and clothes I should be able to smash the world record time in the 50k in my current physical condition.
 

CAMPYBOB

Well-Known Member
Sep 12, 2005
11,945
2,086
113
Your derailleur strings...they're being pulled.



Now...hidden spoke nipples? Those will crush your best TT time!