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Poll: Do heavier riders descend faster?(27 posts)

Poll: Do heavier riders descend faster?Dog
Sep 20, 2001 1:26 PM
If the media can solve all problems with polls, why can't we? Mathematics and reason doesn't seem to be working.

Big smiles.

Dog
Yes, no contest. (nm)peloton
Sep 20, 2001 1:37 PM
nm
and dog....peloton
Sep 20, 2001 1:39 PM
Admit it. You are secretly pollster, aren't you? ;)
My first poll, proud to say!Dog
Sep 20, 2001 1:41 PM
but, it was intended to be a bit sarcastic. I don't care for serious polls.

Big smiles.

Dog
Clydesdale says "Yes," But we climb slowercory
Sep 20, 2001 1:39 PM
Absolutely. It's the old inclined plane trick, different physics than the heavy-and-light-balls-falling trick, but all I remember about it is the name...
Seriously, I've ridden with the same five or six guys for several years, and I'm by far the heaviest. They always beat me up the hills, and I always beat them coasting down, even when we factor out (as much as we can) tires and varying drag and whatnot. Not only that, I've recently lost a bunch of weight, and now I coast almost even with a guy I used to outweigh by 60 pounds but now outweigh by only about 10. And both of us leave the 150-pounders behind.
Seems to be the only place I have any advantage ...Humma Hah
Sep 20, 2001 1:50 PM
... the iron bike and I dive like a brick.
I will be glad test this theory...Kristin
Sep 20, 2001 1:52 PM
with 4bykn at the Hilly Hundred. Though I'm still convinced that my DB rolls faster than other bikes.

To be a truly objective test, we should be on identical bikes. Can someone send me two um...lets say C-Dale 4000si's? Last one down buys a round at the first RBI event.
I will be glad test this theory...4bykn
Sep 21, 2001 7:20 AM
I think the "weapon of choice" should be Colnago OvalTitans. But I won't be picky if somebody does show up with the 'dales! I imagine it'll be the DB vs the Zep', however. If I win, and people swear it's not on account of my mass advantage, then that would prove Shimano's superiority! ;-)
Yes. And no.mr_spin
Sep 20, 2001 2:00 PM
I'm pretty light, so I'm almost always beaten by a heavier rider who has decent descending skills. I am a very good descender, but more weight clearly has its advantages.

But one good friend weighs at least 30 pounds less than I, and she consistently beats me on descents. Needless to say, I am clueless as to how she does it. It's become a running joke. I watch her from behind, and I don't see her doing anything I'm not doing....
Similar situation...Spinchick
Sep 20, 2001 2:07 PM
A friend that I ride with weighs about 10 pounds more than I do. She on her $3,000 something or other (I try not to look too close) and me on my $900 steel Univega. I ALWAYS descend faster - not just faster but ALOT faster. My bike probably weighs 3 pounds more but she weighs 10 more than I do. I've noticed that my non-high end bike rolls mighty fast down hills. On group rides I'm often the first one at the bottom - and not often the heaviest.
"I watch her behind..."Brooks
Sep 20, 2001 2:29 PM
Oh, from behind. Not a bad view I'm sure. Are you sure you're not riding the brakes a bit? ;-)
Probably rightmr_spin
Sep 20, 2001 2:49 PM
We both have titanium bikes, as well as the same wheelset, so it must be I am using the brakes a little more.

Funny thing is, recently I mentioned to my friend that my brake pads were wearing down faster than usual. Her comment, said with a sly grin, was something like "Mine aren't. Maybe that's your problem!"

I'm a gentleman, so I won't comment on the quality of the view. Let's just say I agree and leave it at that!
re: Poll: Do heavier riders descend faster?farmerfrank
Sep 20, 2001 2:09 PM
Absolutely...They call us the "chunky monkeys."Awesome on descents, great to draft behind but a little slow up the hills. Everyone has their place on rides.
Yes, but good hubs also help...Bruno
Sep 20, 2001 2:19 PM
I weigh 176 and in the decends is when I can go fastest compared to other people in my weekly group ride. But I also noticed that when I changed my wheels that had generic hubs to mavic wheels and hubs my speed while decending increased. In fact in the only situation I can tell these wheels are better is when decending not when climbing.
You betcha!look271
Sep 20, 2001 3:34 PM
Being 185 has it's advantages, sometimes. I am always the 1st down descents in a group ride. Now that I climb not as badly as I used to (I'm still no Pantani or Jiminez!), I can actually beat some people up hills (imagine that!)
re: Poll: Do heavier riders descend faster?VW
Sep 20, 2001 3:58 PM
If two person ride the exact same bike and therefore has the same rolling friction. The bikes mechanical friction is therefore same whether is was riden by the heavier or lighter person. We are also assuming air friction is the same for both rider. They are both the same aerodynamically.

We also know that the rate of free fall acceleration is also the same for all object. That is, if two object is throw out of a tall building, the heavier and lighter object will fall at the same rate if the air resistance is not significent (object is small in size). Both object should hit the ground at the same time. This acceleration is call "g" 32ft/second square or 9.81 meters/second square.

Kinetic force F = Mg (the more familiier formula is F = MA)

where

F is the kinetic force
M is the mass of the object (person + bike)
g is the rate of acceleration from gravity (a constant).

From this, we can see that if a person is heavier, then the kinetic force is higher. In another word, the heavier person has more momentum.

If the friction force is the same for both heavy and light person, the friction force has a lot less effect when trying to counteracting the much larger kinetic force of the heavier person. In another word, the bike's mechanical friction has less effect on the heavier person because the heavy person has much more momentum than the ligher person.

Less effect mean, the heavier person doesn't slow down as much by the friction as the lighter person. Just think about a fly colliding with a train will do little to slow the train down. If a fly collided with another fly, the other fly will stop on its tracks.
re: Poll: Do heavier riders descend faster?yeah right
Sep 20, 2001 4:48 PM
A physics teacher would look at this and laugh. Every classical physics problem of this nature can be solved by either by energy-state balance or by using forces and geometry, but please don't mix the two. Also, momentum in and of itself, has nothing interms of a relationship with forces.

BTW: I'm over 280 and I NEVER get passed on straight decents.
Eddy Merckx says...DINOSAUR
Sep 20, 2001 4:46 PM
Go down hill fast, drink lots of beer, bounce lots when hits pavement, get back on bike, go lots faster till you go down again, repeat lots...

Eddy Merckx is my hero
good hero to havezzz
Sep 20, 2001 6:14 PM
especially the beer part. I go as fast as physics let me. Once when I had gained some weight my downhill times did improve over the same course. But then my health is more important than speed.
relax on the bike.breck
Sep 20, 2001 8:57 PM
zzz,
one way to increase the speed on the bike is to relax. Tension slows you down. Percent body fat may be a better indicator of health than scale "weight". Beer should be calculated as 7 gms per calorie, as alcohol is not the usual 4 gms used for carbos, so the effects of a so called 150 calorie bottle of beer is closer to 263 calories which takes maybe 8 miles to ride off. BTW, did add a line to the Vegetarian question you said did not satisfactorily answer, etc.

cheers,
breck
yikes!, zzz ...breck
Sep 21, 2001 6:57 AM
Hay, was up late and spent the day looking for Loosey Goosey whom got scared away last AM by Bob the Cat. My two old fashioned Collie dogs Max and Stormy were sleeping on the job. Bob's a meat eater and Loosey a vegetarian as you might imagine :)

Make that 7 calories per gram and 4 calories per gram :)

....and make that Guinness, St. James Gate, Dublin, Ireland :)))

cheers,
breck
Shooting Star Ranch
Julian, California
Mine too, Dino.breck
Sep 20, 2001 8:41 PM
The great Merckx was one time asked if eating cake was bad for his form.
He quipped, " No, that hills was bad for his form."
One would never have guessed it :)

Semper Fi! Dino

cheers,
breck
Mine too, Dino.DINOSAUR
Sep 20, 2001 9:04 PM
Yeah Merckx was great. A man of few words, he just got on his bike and rode (lots).

Maybe we should re-up and go over a help round up Bin Laden.
I watched a special on TV last week about Chesty Puller. They don't make leaders like that anymore.

Double Semper Fi to you too!
Dino
I hear you, Big Guy ...breck
Sep 21, 2001 7:10 AM
At least it may ( or may not:) be comforting to know that there are a lot of US Old Tymers around to take care of business here at Home if needed. Lot of retired USMC here in the back country and they all feel the same way as you & me, etc.

Hay, see the CHP are back driving Crown Vickies. Still remember your story of the old Dodge "Goat" Magnum doin' the 170+ down the Grapevine outta Bakersfield. Just added a set of TRD dual cats on the V8 Tundra, but will pass on the supercharger for now :)

Semper Fi!
"Don't Tread On Me"

cheers,
breck
I hear you, Big Guy ...DINOSAUR
Sep 21, 2001 8:21 AM
Ford is the only American manufacturer that is pumping out rear wheel drive cars. Thus the explanation for the Crown Vic's. The only reason no one can outrun the patrol cars now is help from the air. The Fords differ from year to year, but they are very comfortable cars to drive.

The legend is they ran a '69 Dodge Polara 440 down the Baker Grade on I-15 (between Barstow and Las Vegas) and timed it at 170MPH. Since the CHP is a year behind with model years this must have happened in 1970. I drove a '69 Polara at the CHP Academy when going through EVOC, fastest car I have ever driven. However my little tricked up 361 Plymouth Satellite is no slouch.

I guess you can relate this to bicycling as when you hit the high speeds you are putting a lot of faith on your tires. Back during the early 70's tire blow outs and flats were common on patrol cars. Same thing with clincher tires, technology has come a long way. Also tire pressure makes a big difference whether on a vehicle or a bicycle. I just had to get something in here about bikes, what happened to the email feature?

Good to see you posting again Breck, did you catch the thread about the Pegoretti CCKMP? (Cocaine cannot kill my pain-Steve Earl)

I can feel the rath of the internet police breathing down my neck for abusing the forum. I plead guilty with an explanation.

Dino
re: Poll: Do heavier riders descend faster?Marc
Sep 20, 2001 7:56 PM
I am a "heavy rider" at 5ft. 8inches and about 200 lbs. The problem with determining the rate of descent is that you first must ascent. Since I do not do much of the latter, I cannot measure the former.
sometimes yes, sometimes no.breck
Sep 20, 2001 8:17 PM
Typically those that can assume the best aero position can descend faster. Increased speed means increased drag. Your heavier bud may not be able to make up the diff., especially if he/she is taller or does not have good down hill aero form. If the down hill descent is steep and has lots of tight turns in it, then all bets are off.

cheers,
breck