Mountain Biking - Does body weight make a difference?

Hey everyone,
I have a potentially stupid question here, but I'll ask it anyway. Is it easier to maneuver/stay on the bike in technical conditions going downhill if you are heavier than the normal person? I'm not trying to make excuses or anything; I know that my downhill performance is pathetic, hence the name ricochet, but man, my 235 pound friends just freaking fly downhill and it never seems to matter what the terrain is and how tight the turns are. Does the added weight help with traction and with keeping the wheels from going out from under you, or does it make no difference at all? I'm a lightweight 165 and I can't come close to these guys downhill. It's like thier wheels are just sticking to the earth. Just wondering what people thought.

Take care all.

hmm good point, traction could be a part of it but i'm neither light nor fast =].

I think it's the ability to focus and enjoy the ride. Question: are they picking clean lines, or are they kind of flinging themselves DH, and holding on for the ride? I'm somewhere inbetween myself, but I'm 120 lbs. I still have to pedal downhill.

Kinda both; they do ride clean lines, but they can also shift and ride over parts on the trail they want or dodge what they don't want to go over. Their just incredible downhillers, and they hardly ever fall.

it could be a little of both. Their weight saves them from having to worry about pedaling, they automatically go fast downhill(I'm 240 BTW) so now the only thing to worry about is the terrain, and braking. Better than worrying about pedaling, shifting, the terrain and braking. Lees to occupy their mind, and possibly their used to the trail. Ride it enough and anything becomes easy.

Hmmmm. This is true....

The bigger you are the less you have to worry about trees slowing you down :roflmao: Kinda like a charging moose.

I doubt it aid's traction. Momentum is important, but at the same time, a light rider is going to have greater ease in moving the bike.

It is most likely bike setup. If they have things set up correctly, then they will fly.

Skill, practice, etc is all important.

I am 150 and I kill my 230lb friends on the DH's. It's bike setup, skill, and the bike itself. Body motion, and lots of things. Don't rely on suspension and you flat out HAUL ASS.

Well actually if everything else is equal, the heavier rider does have an advantage on downhills. ...fact. It's for the same reasons that a lighter rider has the advantage on the uphills. It's that old engineering "force balance" gig. Gets you everytime.

...sounds like your buddies are just fast riders too. Personally, I'm not that fast on descents.

But I bet you outclimb them huh??

in non-technical descents like say road biking, a heavier rider does have a slight advantage as he gets more acceleration from gravity... ---- for example tandem bikes fly downhill

but for technical descents this slight advantage should be insignificant as rider skill makes all the difference (i.e. on technical descents you rarely ride without braking and proper cornering techique gains more than any small advantges from weight).

i would actually think the opposite: that lighter riders should have an advantage downhill as you have less weight/momentum to corner on the same tires (a heavier rider still rides on the same tires). plus a lighter rider can ride the same bike/tires with less pressure before getting a pinch-flat - so can get MORE traction. i think there is probably a trade-off at some point between muscle and weight, so that the ideal for downhillers is probably in the 155-180lb range.

i'm not a big follower of the pros, but i think most pro downhillers are more your (and my) size in the 150-200lbs range with few weighing over 200.

it sounds like your heavyweight friends just have great technique! assuming you are a strong 165lbs you should actually have the physical ADVANTAGE over your heavyweight buddies. sorry, but sounds like you just need to improve your technique.

P.S. i am 6'1" and 165lbs and while not pro, i'm a downhill/technical specialist. i think if i were 180lbs or more i would not be able to ride as well...

I think it does. I think lighter guys do have an advantage on tech dh sections. They tend to float over stuff as bigger guys look like giant plows with wheels. Of course this doesn't apply 100% of the time. Myles Rockwell was a beast and still floated.

I am just generalizing :)

Well actually if everything else is equal, the heavier rider does have an advantage on downhills. ...fact. It's for the same reasons that a lighter rider has the advantage on the uphills. It's that old engineering "force balance" gig.



in non-technical descents like say road biking, a heavier rider does have a slight advantage as he gets more acceleration from gravity...

sorry, but wrong. the only advantage heavier guys have on a descent is they have more momentum to overcome air resistance. the reason lighter guys have an advantage on climbs is that they have to do less work *against* gravity. but two bodies of different weights falling will fall at the same speed because, unlike your internal engine, gravity pulls with the exact same acceleration on heavy and light alike (9.81 m/s^2, varying only slightly from place to place). it simply doesn't care about your weight because it's an external force field.

what's the difference? a light guy can get out of the wind by tucking. a heavier guy often can't, so the momentum gain attached to weight is usually a zero-sum thing.

so the reason your friends are smoking you on descents probably has a lot more to do with technique. brake before the turn, cut the apex (outside to inside to outside again), accelerate out of the turn, don't skid (ruins the trail and is only faster if you don't know how to use the front brake properly), pick a good line, stay out of the saddle, stay on the ground (jumps slow you down, unfortunately :( , for the same reason skidding does), relax your shoulders, don't grip the bar ... and BREATHE! haha seems like that last is the easiest thing to forget. you are guiding the bike downslope, making corrections when it strays; you are not making it go where you want it to go.

i'd say just practice, *very slightly* pushing your comfort zone until you're ripping down the hill - and you should be hanging with your 230 pound friends no problem.

Quote: in non-technical descents like say road biking, a heavier rider does have a slight advantage as he gets more acceleration from gravity...


sorry, but wrong. the only advantage heavier guys have on a descent is they have more momentum to overcome air resistance. the reason lighter guys have an advantage on climbs is that they have to do less work *against* gravity. but two bodies of different weights falling will fall at the same speed because, unlike your internal engine, gravity pulls with the exact same acceleration on heavy and light alike (9.81 m/s^2, varying only slightly from place to place). it simply doesn't care about your weight because it's an external force field.

well, i was in a hurry and i was afraid someone would complain about my wording...

yes, you are correct that gravity does act proportionally, BUT in most long long-technical descents the increased momentum to overcome drag DOES make a difference as a heavier rider usually has proportionally less surface area than a lighter rider --- i.e. 2 guys both 6" tall, both with broad shoulder and one 160lbs and another 230lbs --- the frontal surface area of the heavier guy and his bike will probably be only marginally greater although his weight is SIGNIFICANTLY greater. or a Tandem where the back rider barely increases the drag, but obviuously adds to the weight.

but as i stated before, for technical descents this slight advantage should not be a factor - actually as
Maelstrom and I stated more weight should be a DISADVANTAGE (but rider skill is what really determines it)

The point is to be smooth and consistent, when you pass your friend, trailside with a flat or broken part(non body wise) wave hi and keep going if the going's hard, if not stop and help. Unless the friend is injured, then you stop regardless.

lol sorry about that then nathan, the word acceleration threw up a red flag for me!

you are also correct about the weight and surface area argument. take a typical length scale for a human (like height, for lack of a better), then weight goes as volume or height cubed while surface area only goes as height squared. but in order to tell whether the weight or the surface area makes a greater contribution to any change in speed, you have to know the drag coefficient and the cross section of the rider the air sees (ie. when tucked, which rider looks bigger to the wind). friction is pretty tough to calculate, but at higher velocities can generally be modelled proportional to velocity squared. so for a given weight at a given speed, if either drag or cross section are too large then small changes in air resistance will more than offset changes in weight.

in short, differences either way will be small and situation dependent - and the faster the speed, the less difference weight should make. technique, on the other hand will make a big difference. i guess we're all saying the same thing, lol some of us are just more long winded than others ;)

Skill=Fast :D

Big guys, say over 200lbs are at a huge disadvantage. You need a few things to be good in DH racing besides good bike handling skills. One of them is to be in good shape, and if you are a bigger guy you will use more energy moving yourself around and just holding yourself up but your longs are not proportionately larger to give you more oxygen. Big guys get tired, that's all there is to it.

A huge second factor is that big guys can't corner as well. You have more mass to turn but don't have proportionately more traction to turn it with. This is an issue in any form of racing from cars to motorcycles to mountain bikes, lighter things turn faster.

Just the fact that Maelstrom mentioned Myles Rockwell being a "monster" should illustrate that. He is considered absolutely huge for a racer. Guess what HUGE is? 6'2", 195lbs. Most successful racers have been a lot closer to Gracia or Peat's weight.

Big guys, say over 200lbs are at a huge disadvantage. You need a few things to be good in DH racing besides good bike handling skills. One of them is to be in good shape, and if you are a bigger guy you will use more energy moving yourself around and just holding yourself up but your longs are not proportionately larger to give you more oxygen. Big guys get tired, that's all there is to it.

A huge second factor is that big guys can't corner as well. You have more mass to turn but don't have proportionately more traction to turn it with. This is an issue in any form of racing from cars to motorcycles to mountain bikes, lighter things turn faster.

Just the fact that Maelstrom mentioned Myles Rockwell being a "monster" should illustrate that. He is considered absolutely huge for a racer. Guess what HUGE is? 6'2", 195lbs. Most successful racers have been a lot closer to Gracia or Peat's weight.


I weigh 235lbs
You've obviously never raced against a an Expert level Clydesdale and I don't know about you but many of us "bigger" guys have a LOT more stamina than some of the toothpicks I see on the trail.

You've obviously never raced against a an Expert level Clydesdale and I don't know about you but many of us "bigger" guys have a LOT more stamina than some of the toothpicks I see on the trail.

That's a ridiculous comment. Did I hurt your feelings or something? Never anywhere did I say that big guys were slow, just that they were at a disadvantage. I have seen big guys who were fast, just not as fast as the smaller guys. Go back over the DH champions of the last 10 years. Separate them into a list of riders over 200lbs and riders under 200lbs, then get over it.

I weigh 235lbs

Sounds more like you're bashing yourself. I know Clydesdale class riders who can out handle just about anyone else on the course (skinny guys included) I still don't see your so-called "disadvantage".
As far as hurting my feelings :roflmao: yeah right!

As far as the DH champs go who cares? You're the only one talking about DH racing here. He was talking about a decent with his friends- didn't say diddly about it being a DH or an XC or even about it being a "pro race" If you can handle your bike better than the next guy you're going to win - end of story.

Sounds more like you're bashing yourself. I know Clydesdale class riders who can out handle just about anyone else on the course (skinny guys included) I still don't see your so-called "disadvantage".
As far as hurting my feelings :roflmao: yeah right!

As far as the DH champs go who cares? You're the only one talking about DH racing here. He was talking about a decent with his friends- didn't say diddly about it being a DH or an XC or even about it being a "pro race" If you can handle your bike better than the next guy you're going to win - end of story.

I think he was taking two riders of similar ability to rule that out as a possible area of advantage. Then only comparing them based on weight. Take two average riders of similar ability and one is 150 and the other is 250...the 150pound rider has the advantage...take a 250pound good rider with a 150 pound average rider and the 250pounder will be faster...weight does make a difference.

I think he was taking two riders of similar ability to rule that out as a possible area of advantage. Then only comparing them based on weight. Take two average riders of similar ability and one is 150 and the other is 250...the 150pound rider has the advantage...take a 250pound good rider with a 150 pound average rider and the 250pounder will be faster...weight does make a difference.

Yep, that's exactly what I was talking about, an advantage. Not that the lighter guy will be faster, just that weight is an advantage. Skill is also an advantage, balls, decent equipment, being in good health. They are all advantages, things that help.

Maybe a completely unrelated example will make this more apparent to people. If I asked if a rear brake was an advantage in DH racing most folks would agree yes. If you didn't think so you'd just take the brake off your bike and save a pound right? I saw a race where in the first corner Steve Peat ripped his rear brake line out and had to run the whole race with no rear brake. His competitors had an advantage in the braking department. Peat still won the race, he had other advantages, such as skill and fitness.

That wouldn't cause me to go and say something stupid like "If you think rear brakes are an advantage you've obviously never seen Peaty race without one". And if I did, wouldn't it be apparent I was a dumbass?

You've gone too far calling people stupid and dumbass.

I'm not calling anyone anything here. I merely asked if I said something stupid if you would think I am a dumbass. It's a question, not a statement. So, would you?

Any resemblance in my comments to characters real or fictional is coincidence. :D

O.k, busting out my mod duties here!

Raiyn, he's right he didn't call you names, ease up dude! Take a step back, count to 10.

L8R
(Now watching this thread to make sure you guys behave!)

Thanks like I don't have enough to do already!