Hi y’all. Hope everyone had a good Xmas. In preparation for IMC, I have the following question:
If I drill 8-10 (1/4") holes in my handlebars and don’t use any cork tape on my handlebars, how much time could I save (approx.) during IMC? I use TTT handlebars. I’m 5’9" and 180 lbs., but plan to be around 160 lbs. for IMC.
Are you serious?!
OK - 2.75 secs over the 112 miles
let me see…8-10 holes…by my calculations…absolutley…nothing!!! : )
Instead of sacrificing your body by making your handlebars weaker…just cut 3" off your shoe laces and you’ll save about the amount of weight. : )
112 miles without bar tape might make matters worse. You may become so uncomfortable that any time savings will be lost by your moving around and taking road shock directly into your hands. : )
Seriously…I don’t think it will ever matter.
I’d bet you’d lose time due to the added tubulence.
You could get the same weight savings by running the bike without the headset top cap.
-SD
Keep losing your body weight. Up until a certain point, your VO2max will increase as you drop weight. You should therefore be able to sustain greater and stronger efforts over a longer period of time.
Also, go with lighter components that you haven’t artificially diddled with. That “drill the holes in the equipment” is an old gag from the mid-80s that Tinley and the rest of the originals used to do. Besides, it’s dangerous.
Speed costs. Figure a thousand bucks for every pound under 18 or 19, nowadays, to get the bike down to the 15 or so pounds that the TDF riders were sporting this year.
Tony
Not to hijack this thread but, what would the threoretical time difference be for each extra pound over an IM / .5IM be? Also, does it make a difference if it’s a rider pound or a bike pound?
My point, exactly. I’m not an engineer, but there are plenty on this forum. Other than rotational weight of the wheels, I’d say that it’s probably (again, up to a point) easier to take a little of the chubbiness off of the body, and go with lighter components, than to worry about drilling holes and such.
T.
Here is what 400g looks like over a 20k time trial - six seconds on a hilly course.
This was calculated to show the minimal weight disadvantage of using Rotor Cranks compare to conventional cranks. The performance benefits far outweight the speed lost from the additional weight.
As long as your tri bike is under 25 lbs then it really matters little in my opinion.
The thing that cracks me up, especially at the 1/2 or IM distances, is that people will spends thousands to come in with a 17 pound bike, then will load it up with 32 or more ounces of fluid bottles, extra spares, toolkits “Bento boxes” etc., so that by the time they’re done, the bike weighs 22 or 23 pounds. And they waddle onto the bike, bloated by 5 pounds or more of water weight gain and soaking-wet trisuits and such.
T.
You’ll get a DNF when your handlebars break and you wind up in the hospital with a broken collarbone.
Aim for a hearty dump pre-race instead!
So, you agree that a hearty BM could be the answer to the speed issue?
T.
Weight is a second order affect compared to aero, meaning aero is 10 tims more important.
The weight you are saving is less than a gel pack or 1/2 a powerbar.
Since you are either having fun with us or very new to cycling, here is a money saving tip. You can’t buy speed in your first years on the bike. You have to earn your speed with training and hard efforts. You’ll be faster in 5 years than you are today. If you are 20 lbs overweight going into the season, you’ll be working mostly on weight loss.
" Weight is a second order affect compared to aero, meaning aero is 10 tims more important. "
Really? So you’re saying that aero is 10 times more important than mass both on a level road and climbing a 10% grade? How do you measure importance?
Obvious troll.
Really? So you’re saying that aero is 10 times more important than mass both on a level road and climbing a 10% grade? How do you measure importance?
I’m paraphrasing Kraig Willett from his website. He has done substantial studies in the tunnel and using power meters. His website has more data than you can absorb in a day. http://www.biketechreview.com/
I would also take all aero data with a grain of salt. Many times, the data presented is for one item, i.e. a sampling of aero bars are put into a tunnel and a winner is announced. What that doesn’t take into account is the bike itself, rider profile, mission (IM length event or 10-40K length events), course profile, etc.
"I’m paraphrasing Kraig Willett from his website. He has done substantial studies in the tunnel and using power meters. His website has more data than you can absorb in a day. http://www.biketechreview.com/ "
Then you should try to paraphrase more accurately. From http://www.biketechreview.com/archive/wheel_theory.htm
“Roughly, the average rider power requirements on a course with a zero net elevation gain is broken down into 60% rider drag, 8% wheel drag, 8% frame drag, 12% rolling resistance .5% wheel inertia forces and 8% bike/rider inertia. The uphill TT example given is a special case where the rider aerodynamics and the bike/rider weight have nearly equal contributions to power – somewhere around 35% each with wheel mass contributing around 1%. The steeper the hill, the more important mass becomes and the less important aerodynamics becomes.”
Kraig recognizes that there isn’t one single value for the ratio of aero drag and gravitational force. The ratio depends on speed and grade.
I was quite accurate, just not as detailed. The aero drag numbers you quote add up to 88% with rider/bike weight at 8%. Which puts weight 11 times less vital than aero.
I didn’t provide the details because: 1. some items on his site are pay only and I don’t think I have the right to give his stuff away. 2. People should go learn this stuff on their own as you and I did.
I think when the handlebars break and you fall, you will spend 3 months in hospital and rehab and gain 11 pounds from inactivity… leading to a running pace of 33 sec additional per mile.