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Why are mtb handlebars designed with upsweep?

10K views 17 replies 11 participants last post by  Xcyclist  
#1 ·
I notice that pretty much all mtb handlebars are designed with about 5 or 6 degrees of upsweep. I find that the upsweep puts a lot of pressure on the outside of my palms and it gets painful, so I roll my bars back to get rid of most or all of the upsweep. If you hold your fists out in front of you, it seems like a much more natural position to have the outside of your palms lower than the inside. So why are bars designed with upsweep?
 
#2 · (Edited)
Well, first, I'd guess that bars with some up and back sweep sell better than completely flat bars, which seem to be virtually nonexistent. And that is probably the result of providing riders with some choice to indulge their personal preference. And, as you point out, you can mostly eliminate it.

I suppose all of your bars are OEM, which probably means they were chosen to be adaptable to rider preference.

I don't find the position uncomfortable and it seems like it might be advantageous to have the outside of your hand bearing on the handlebar for pushing it down in turns, but I haven't experimented with it. I see a couple of articles discussing bars that say the kind of average 4-6 degree upsweep produced a "neutral wrist position," without citing any ergonomic reference. It really isn't much.

But, ultimately, you do you. Most people seem to like some upsweep and if you have a zero upsweep bar there's nothing you can do to gain sweep so there's less ability to "customize."
 
#4 ·
The way handlebar dimensions are described is very unsatisfactory. They really only have one angle with an offset up and an offset back. (Similar to problem with "seat tube angle" on a geo chart for a bike that has a seat tube with a bend)
 
#5 ·
well, easier description is that there’s a bend angle and there’s a secondary <angle, offset>. By rotating bar the bend becomes back sweep and upsweep for the grips. But then a bar can also express an offset at some angle, effectively modifying reach and stack. You could add reach and even lower the stack with bar offset. Point is angle off offset is fixed, the up/back depend on bar rotation.

step 1: imagine if bars were all purely a bend on a plane, with no offset. Assuming there was enough bend you could rotate the bar to get the back sweep and upsweep that you wanted. Then rise is purely a steertube stack problem and reach is purely a stem length problem.

Step 2: make stem as short as possible, and slam it. That’s the lightest stem and shortest steer tube for your bike. Determine the extra reach and stack you want and build it into the bars as an <angle, offset> pair, literally moving the bar grips to where you want your hands. You’ve now got the lightest setup as your custom bar is the straightest solution for you.

conclusion: an offset bar might be optimal for someone… :)
 
#6 ·
I got a new Trek bike that came with the one-piece RSL bar/stem combo. They have 6 degrees of upsweep built in. They are beautiful and light, but I can't rotate the bars to reduce the upsweep. I'm hoping to get used to them, but they make my hands hurt so I might have to ditch them.

For decades I used only flat bars, and set them up level, with no upsweep. A few years ago I started using low-rise bars, and I still like to rotate them back so that there is just a tiny bit of upsweep. This rotation also increases the backsweep, which I think puts my wrists in a more natural position.

I can see where upsweep might encourage keeping the elbows up, and if you view it from shoulder level instead of bar level it looks less like upsweep and more like backsweep, but I still find the standard 5-6 degree upsweep uncomfortable for me personally.
 
#13 ·
I just put this Ritchey Kyote on my rigid mtb.
Love it! May consider trying it on my SC hightower.
FWIW I've been running Kyote bars for three years on my Timberjack, which mostly sees bikepacking duty with some trail riding. Love 'em. And they are (were?) cheap! I found mine for like $32 but that was pre-pandemic. Good amount of 31.8 space at bar center for mounts and straps (was always an issue w/ Answer 20/20 bars), the forward offset keeps effective reach intact, and the backsweep feels great on long backpack days without feeling totally funky on trails (which, for me, was a problem w Jones bars). The Kyote bars are part of the reason I'm considering a move to 12 or 16 degree on my main trail bike.
 
#10 ·
Coming in a bit late here, but worth noting that Syntace bars are spec'd as zero upsweep. I'm looking at a model with 12deg of backsweep. But as others have noted here, the upsweep/backsweep changes as you rotate the bars. If I take a more typical 8deg back and 6deg up handlebar, and rotate it back to a point of 0deg upsweep, then what is the approx. backsweep? I'm too lazy to do the geometric math . . . but seems that rotated 8/6 bar may look very much like a 12/0 bar in terms of final grip angle, albeit with a bit of reach-reducing rearward offset?
 
#11 ·
This is the combined effective angle if the backsweep and upsweep start at the same point on the bar:

Image
 
#15 ·
For a one-piece bar/stem spec'ing upsweep and backsweep makes sense. These Bontrager RSL bars came on a new bike I bought. They have 7 degree backsweep and 6 degree upsweep. They are beautiful lightweight bars, but I wish I could roll them back to get rid of most of upsweep.


Image
 
#16 ·
For a one-piece bar/stem spec'ing upsweep and backsweep makes sense. These Bontrager RSL bars came on a new bike I bought. They have 7 degree backsweep and 6 degree upsweep. They are beautiful lightweight bars, but I wish I could roll them back to get rid of most of upsweep.
Yep, totally agree.

7+6 = 9... :)

I have a few bikes I feel are dialed but no one makes the exact fit I want. Combined bar stem is the dream setup but pretty unlikely for most of us, and thats before considering the price. Beautiful though.

FWIW: Enve 785 m6 bars weigh 215. Their stupid expensive stem is allegedly 85g so total is 300g. The rsl in 800/35 is 270g. Save an ounce and a bunch of money but lose ability to adjust the fit...
 
#17 ·
This sounds like the bars are rolled too far forward. So the ends of your grip are sticking up. The rise is really just from the bend in your bars. And the sweep is to help your hand and wrist stay in line and not having to bend at the wrist. First pic is bars to Forward which will put more pressure on the outside of the palm and bend your wrist. Second pic shows bars that will put your hands wrist in a more natural position. Should help relieve pressure. The bars should be rotated to allow for even grip pressure across the whole hand on the grip. You will still have a very slight rise of the grip. Then rotate my brake levers to a 45 degree angle.
 

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