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How does Bar sweep work?

demo 9

Turbo Monkey
Jan 31, 2007
5,910
46
north jersey
Yup, another demo 9 thread, lets try to keep it civil. I am interested in knowing the science between upsweep backsweep and so on. Most bars are different, although not by much, i cannot find out how it "works". I find that i run almost all of my bars tilted very far back, thats where it feels comfortable, but is there a downside to that. (health wise, or riding wise) It seems that alot of people buy bars on width, but not so much on sweep, which may be equally important? Asked all the people i knew, couldnt get an answer, so any help would be appreciated.
 

ianjenn

Turbo Monkey
Sep 12, 2006
2,998
702
SLO
Ride the bars how they feel most comfortable. Yeah there are kids around here who weigh 140 LBS and have 32" bars probably wear about a 40 in a suite its funny. The bars are wider than their shoulders.
 

sanjuro

Tube Smuggler
Sep 13, 2004
17,373
0
SF
Width is easy to estimate but sweep still tends to be more of a feel. Bars sweep back and up, and tilting them also changes the "feel".
 

Tame Ape

BUY HOPE!!!!!!!
Mar 4, 2003
2,284
1
NYC
Do you own all the bikes in your sig? Since you can clearly afford several different bikes, I'm going to assume you can afford several different bars. Go buy several different bars, mount them and see what works for you.

Otherwise, search this and any other bike forum for information.
 

NoUseForAName

Monkey
Mar 26, 2008
481
0
Anyone ever asked Truvativ/SRAM why they made the Boobar with such a wierd sweep?

Since they sponsor 80% of the worlds top gravity atheletes, you'd think they knew a thing or two about bar sweep etc. At least they'd have a team of test riders to give feedback.

Boobar 7 deg X 5 Deg upsweep, everyone else 8 or 9 deg.
 

was?

Monkey
Mar 9, 2010
268
30
Dresden, Germany
there isn´t that much science behind it.
upsweep = vertical plane, backsweep = horizontal plane.
healthwise, a neutral wrist position is preferable. wider bars may have more backsweep for that reason.
too much upsweep is uncomfortable if you lean the bike for cornering, or move a lot from side to side.
 

demo 9

Turbo Monkey
Jan 31, 2007
5,910
46
north jersey
I can theoretically go and buy a bunch of bars,but id rather not. i have been running sunlines for a while now. V1 19mm rise 745 width, i like them, but i notice i keep mine rotated back a bunch, so the upsweep eventually becomes "downsweep" I happen to like them this way, i recently won a set of atomlab bars, i put them on, and i just dont like them(its all preference) I called a buddy, and he said the sunlines happen to be very "extreme" as far as sweep goes, got me thinking, what its designed for. In a nutshell, do i have X wrists or X preferences compared to somebody else who has Y wrists and Z preferences, ect... I was also curious if it was bad to have my bars beach cruiser style. (obviously not that much) I figure different companies have different sweep for a reason, wasnt sure if there was a science that determines what the best bar for you is.


EX: does backsweep (theoritically) increase/decrease your cornering, will upsweep make you pump better? ect?
^ **** description, but you get the idea
 
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EVIL JN

Monkey
Jul 24, 2009
491
24
Only thing i have found is that on long xc/am rides a 8 degree sweep makes my wrist hurt quite a bit more than with 9 degrees sweep. For anything but purely gravity riding backsweep should depend on your shoulder to handlebar width since to little sweep can hurt your wrist when you ride for extend perids of time.

Otherwise it is more about what feels good and make you feel connected to the bike, for me bars, grips and pedals is the most important factors to feel good on the bike, so its worth to try diffrent setups to feel what works.
 

iRider

Turbo Monkey
Apr 5, 2008
5,648
3,089
Syntace offers most of their bars in several backsweeps (2-3 usually) so you can fine tune to what works for you.
 

Slater

Monkey
Oct 10, 2007
378
0
Actually upsweep is not ergonomical.

Just rest your hands by your side. Totally relaxed. Then raise your arms straight out in front of you, without twisting/moving your hands until your arms are almost parallel to the floor. You'll notice that your hands are in a position that a theoretical bar they're holding has down sweep and back sweep. Ever wondered why clipons on sport bikes are "tilted down"? The lower your bars are, the less upsweep/more downsweep they should have.

Of course there is preference to consider, but physiologically speaking its fairly simple. Personally I've got my Sunline flat bars rotated so that the bend ends up being almost all backsweep and a tad bit of downsweep. It feels great, and has reduced upper body/hand fatigure for me.
 

demo 9

Turbo Monkey
Jan 31, 2007
5,910
46
north jersey
user error man. and really, no comment on my icp pic? i made that especially for you.


but no i feel you. I really liked the sweep on my sunlines. still one of my favorite bars.
I liked the pic, but i cant comment every single 1! IMO, your title should be something to do with "got pics" or "caption whore"
 

dropmachine

Turbo Monkey
Sep 7, 2001
2,922
10
Your face.
I['m not defending Demo9, but give him a break. The guy is asking an actual question seeking to try and understand something. Particularly funny from a group of people that thing 30g on a set of pedals actually matters.
;)

Yeah hes young, dumb and completely clueless about a lot of stuff, but if hes asking an actual question so wheres the harm in trying to teach him? I bet others on here would learn a lot too.

I'd help you out Demo, but to be honest I am not sure either. I know they are trying to reach a balance between natural positioning and putting you in a position to optimize your power output, but beyond that it seems to be all guesswork to me. Since each person is different, I can't see how any one bar would suit all riders. I do know that of all the bars on the market, Answer Protapers seem to have the highest regard to them in terms of feel. But I think it really does just come down to feel, ya know?

I did get it explained to me like this one time though. Hold a broom at arms length, both arms straight out. Now, slide your hands to the end. Without sweeping back you get an un-natural bend to your wrists, which is not only uncomfortable but also limits your power output, since everything it out of alignment. Its weird too, and then you'd be riding a broom too.

If you wanna get your mind blown, talk to a roadie about seat positioning. It will likely kill you.
 

Tetreault

Monkey
Nov 23, 2005
877
0
SoMeWhErE NoWhErE
there is no science or preferred way to do this, which is why i don't even know how to respond. hold the bars, are the comfortable? no? adjust the positioning, more comfortable? done.
 

dropmachine

Turbo Monkey
Sep 7, 2001
2,922
10
Your face.
I got ya, but that doesn't work for all bars though ya know? I've had some where no amount of fidgeting with them could make them feel right. They were just...wrong. And then some bars that you just stick on, and they're bomber right off the bat. I have no idea why though.

TAKE THAT SCIENCE!!!

 

NY_Star

Turbo Monkey
I know that people make a lot more out of it in the moto and atv world. I have used a flat bar with 11 to 12 degs sweet that i rotated up to have like 9 and 3 or 8 and 3 something like that. A friend had sunlines. They were tilted at a weird angle and it made the bike ride like trash. Hurt you wrist bad. I dont know what it is about them but i think it has to do with length - Width, and Shoulder width. Get it all right and it works, get it wrong and it sucks. I know my bars are wider then my shoulders but i dont know where that rule came from. They feel much better wider but not to an extreme.
 

demo 9

Turbo Monkey
Jan 31, 2007
5,910
46
north jersey
Dropmachine, thank you-moving on, i have the sunlines, i like them, i happen to like them tilted very far down, "beach cruiser" style, i like it, im happy with it, however, i want to make sure that this isnt bad, health wise mostly, but even riding wise. I know many people buy different bars, many people dont care/pay attention, im particularity "sensitive" to bar position, and it can be difficult for me to find what works. I wanted to make sure it wasnt "o you dummy, your 5-11 riding 5 by 9, you idiot, you totally need 8 by 2, because of DW's law" I know when i worked at the shop, roadies constantly got "fitted" to their bikes, sometimes taking an hour or more. I dont happen to know much, but i want to make sure i am not doing anything "bad" Doesnt help when you ride around the races and see every bar tilted forward, and think to yourself, hmmm, why are mine so far back. :)
 

demo 9

Turbo Monkey
Jan 31, 2007
5,910
46
north jersey

forward

neutral

looking at pictures of the pros bikes, seems like most of them are tilted forwards, food for thought for the rest of you, i know i cant ride like that
 

motomike

Turbo Monkey
Jan 19, 2005
4,584
0
North Carolina
demo 9 said:
i have the sunlines, i like them, i happen to like them tilted very far down, "beach cruiser" style, i like it, im happy with it, however, i want to make sure that this isnt bad
Then roll with it. I tilt mine until it feels good, because with bike setup its all about you and not what the internet feels. If you are curious about other setups then tilt your damn bars a different way and ride it to see how it feels.

Ricky Carmichael used to run his bars tilted way back/down for a few seasons or so. It looked so wrong but he was happy with it and no one questioned it. And what sort of health risks are you talking about? Wrist related or something?
 
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davep

Turbo Monkey
Jan 7, 2005
3,276
0
seattle
neutral

looking at pictures of the pros bikes, seems like most of them are tilted forwards, food for thought for the rest of you, i know i cant ride like that[/quote]

The rotation WRT to the ground is irrelevant. What matters is the 'back' and 'up' sweep WRT to a plane from your shoulders to your wrists, and your relative elbow position (in vs out)

Clip-ons were mentioned above, and the reason they are swept downward is great example. Look at a rider on a crotch rocket in a tuck....shoulders are about even with the bars, and elbows are tucked in for aero = downward sweep.

No look at moto where the shoulders are far above the bars, AND elbows are up an out to give more leverage to control the front end...Bars are generally up-swept [U]WRT the ground [/U](actually closer to coplanar to the shoulder hand plane).

The current riding style for the majority of DHMTB pros is elbows up and out, and bars low WRT the shoulder. This dictates more up-swept bar position.

None of this is mysterious...you, like I have hands, elbows and shoulders. Move those body parts and see how their position changes in space.
 
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demo 9

Turbo Monkey
Jan 31, 2007
5,910
46
north jersey
Wrist related or something?
Yes, sort of like how when you learn to type they tell you wrists off the desk otherwise "something bad" will happen. Extremes are extremes for sure, but its worth perusing before i rip down a mountain with a bad position on my wrists, alot of health problems come from posture, id think it would be compounded if you consider what we do,

Dave, thanks for the help, good advice there + rep for u
 

saruti

Turbo Monkey
Oct 29, 2006
1,167
73
Israel
thinking about it,
I think there is a reasone for the placement of the logo on front of the bar.
doesnt the logo should be faceing forward?
 

zdubyadubya

Turbo Monkey
Apr 13, 2008
1,273
96
Ellicott City, MD
demo... to me it sounds like you need a bar with more backsweep than the sunlines. you are tilting the bar sooo far back so as to use some of the upsweep to gain mm's of backsweep. as well, you are running almost 0 upsweep. sounds like you need a flat bar with more backsweep and a shorter stem? the sunline is a 5x9. the sunline flat bar has 11 degrees of backsweep.

maybe try this:



and this:

 

MarkDH

Monkey
Sep 23, 2004
351
0
Scotland
I have my bars rolled forward so that I have practically no backsweep. Can't ride a bike that has rolled back bars, makes my wrists roll back and feels really strange. I wouldn't be too concerned about health problems unless you notice discomfort in your wrists, hands or arms.