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Doctor
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dustinp43 said:
Hi Guys, can you tell me the difference between the 2 types of bars...I'm looking into getting a new bar and I always see the 2 different options?

Is the 31.8 stronger?
You'll need to have a stem that will accommodate the larger diameter bars.

I'd assume that 31.8 is stronger than 25.4 diameter, all other things being the same (material, workmanship, etc.). Have you ever broken a handlebar? Me neither. So, does it matter?

It may be that this new, larger diameter of bars is for carbon-fiber usage.

jeff
 

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Alien Surf Team
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From an engineering point, even though a larger diameter would have more distance around the circumference it could have a thinner wall and end up being lighter. To some limit this is true. However I think in reality given the same model bar the larger one is just going to be stronger and very slightly more heavy.
 

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Razorfish said:
From an engineering point, even though a larger diameter would have more distance around the circumference it could have a thinner wall and end up being lighter. To some limit this is true. However I think in reality given the same model bar the larger one is just going to be stronger and very slightly more heavy.
Exactly. You can make stronger bars lighter and you can make burlier bars as well.
 

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The oversized 31.8mm clamping diameter bar is stiffer and either heavier or weaker (needs to be heavier to be the same strength). Our local Easton rep said that my favorite handlebar, the Havoc 25.4mm, is 20 or 25 percent stronger than the Havoc 31.8mm bars (which are approximately the same weight, and same material and manufacturer). I'm 225 lbs and do a lot of DH/FR, and I strongly prefer the 25.4mm bars because they have more give (not nearly as hard on the body on a multi-day Whistler trip).
 

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watermoccasin said:
The oversized 31.8mm clamping diameter bar is stiffer and either heavier or weaker (needs to be heavier to be the same strength). Our local Easton rep said that my favorite handlebar, the Havoc 25.4mm, is 20 or 25 percent stronger than the Havoc 31.8mm bars (which are approximately the same weight, and same material and manufacturer). I'm 225 lbs and do a lot of DH/FR, and I strongly prefer the 25.4mm bars because they have more give (not nearly as hard on the body on a multi-day Whistler trip).
That only means the 25.4 Havoc is a heavy bar, but oh well
You think manufacturers would make something that isn't actually worth it?
 

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Old man on a bike
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noodletips said:
Not needed, but is it worth it? That's another question altogether.

jeff
Well luigi did say worth. The manufacturers surely find worth in new stuff to sell, but as to having real value? That's another question altogether...:rolleyes:
 

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retrogroucho
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No question worth asking is a stupid question, I'm not sure why you'd say that. But like the others said, since the center section of the bars receive the most stress/force, the larger diameter (ie more surface area) can better distribute a greater amount of force before failing.
 

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Honestly, I bought mine for the look. I like the oversized look better. It just seems to fit the bike I have. I went with a Race Face Deus XC and a Thomson x4, and they're the best looking parts on my bike right now. The front looks nice and dialed with the shimano xt shifters and deore levers. The rest of the bike...looks like a frankenbike, but its getting there.

I also liked how with the Thomson you don't need as much torque. Not sure if that has anything to do with the bar diameter though.
 

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I seem to remember when the oversize bar appeared, Thomson were slow at re-working their stem to match. Something about them needing to re-work the design to be strong enough. If I understood it correctly, you couldn't just make the hole bigger in the stem, otherwise you'd be removing valuable material. So they had to totally re-work the whole stem/handlebar hole. Now I trust Thomson stems totally, but I wonder if we have weaker stems from other manufacturers as a result of the newer handlebar size?
 

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I just picked up a 31.8 RF stem and bar. Well, it's bigger. I think with the bar, it also depends on how far the 31.8 tapers. I hated an FSA bar I had because the 31.8 went into the grip area, preventing proper inboard placement of equipment. The RF ones I have taper before the bends. Then there's the clamping type (4 bolt/2 bolt) and other factors.

Stronger/weaker? I don't know. I think the clamping type has a bigger influence, as I went from a 2 bolt to a 4 bolt bar clamp. 31.8 also allows me to use different bars that are generally available in OS, though that is insignificant. I can also interchange with my gf's bike now, so things are quite a bit easier.
 

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I think that physics logically give the 31.8 bar the edge.

1) The added clamping surface the 31.8 bar gives is something I didn't take into account.
2) Also, the possibility to use more material (without taking weight into account) will obviously make for a stronger bar.
3) The wider diameter also helps distribute the stress the bar regularly takes, this would make for thinner walls and reduced weight with about the same strength.
4) Also, my impression is wide bars only come in the 31.8 format? (I might be wrong here, someone correct me)

Anyway, IMO 31.8 bars are the way to go. At the end it's a matter of personal opinion and what each of us like. But I believe there are a couple of reasons why oversized bars are not only a marketing deal, but a better bar.
 
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