# Is there significant weight Savings between Alloy and Carbon Posts and Bars?



## jbsmith (Aug 3, 2008)

Considering upgrading to a carbon bar and seatpost, but for the cost I might not unless there's a decent amount of weight savings.

How much weight could I expect to save by going carbon in these two parts?

I've pretty much lightened everywhere else I can (within my budget - wheels, cassette, hubs, crank, pedals)


Thanks!


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## sissypants (Sep 7, 2016)

The answer is yes, you can save a lot of weight in your cockpit (bar, seatpost, stem, saddle).

Handlebars that are carbon can weigh under 100g, but for practical purposes, a 720mmx31.8 flat handlebar will average 140-160g on a weight weenie budget. You can also get chinese handlebars for as cheap as $15 (I use these, no problems).

Seatposts that are carbon can also shave a lot of weight, there is a new chiner seatpost which looks indestructible (nearly) and is becoming mega-popular (more than 2000 orders in the last 3 months across eBay and Aliexpress). It's $31 and 160g for 31.8x400mm with Ti bolts:

https://www.aliexpress.com/item/Roa...rews-Seatposts-135g-UD-Matte/32822592827.html

Unlike handlebars where there are mixed feelings about using Chiner off-brand models (about 1 in 7 break while riding), seatposts seem very robust.

Stems are best left alloy. Get the Kalloy UNO stems from eBay. Sub 100g and $25. Any angle or length you need is available.

If you prefer brand names, you'll be paying a LOT of money to achieve significant weight savings. Check out Mt. Zoom, KCNC, Schmolke, Darimo, Tune, MCFK, etc.


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## JoePAz (May 7, 2012)

I saved 258 grams by changing out my seatpost and handlebar

Stock
Handlebar 720mm aluminim Specialized 315g
Seat post 30.9 400mm aluminium specialized 343

Carbon
Handlebar 720 Raceface Next 179g
seat post 400mm Syntace P6 221g


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## gmats (Apr 15, 2005)

In my experience, finding light weight seatposts were limited (compared to Al). I found good weight savings in Ti. 

Handlebars I've found lightweight carbon bars, especially if you're looking for risers. Ti's hard to make in shapes other then swept. And anything beyond that becomes EXTREMELY EXPENSIVE.


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## jbsmith (Aug 3, 2008)

Thanks for the replies - I'm a little concerned over breaking carbon bars while riding vs bending or denting a metal one - seems like it could be a non-issue vs a catastrophe. so I'm trying to figure out if the weight savings is worth it to me.

Again thanks for the thoughts.


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## GRPABT1 (Oct 22, 2015)

People have been racing DH WC and EWS on carbon bars for years, unless you crash it's a non-issue with a reputable brand bar.


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## sissypants (Sep 7, 2016)

GRPABT1 said:


> People have been racing DH WC and EWS on carbon bars for years, unless you crash it's a non-issue with a reputable brand bar.


I have thousands of miles on $15 carbon bars and never broke one. The #1 reason people break them is because of overtightening brake lever mounts, shifter mounts, and lock-on grips. I've seen four bars that broke this way. The #2 reason people break them is because they want to ride them at some funny angle which the bar wasn't designed to run at. If you mount them centered and with backsweep going back (not up) you should be just fine. Carbon is a unidirectional material, so you take advantage of its properties by installing it correctly and not crushing the fibers.

And I should add, if something breaks, you usually have plenty time to respond. One guy who broke his after a crash said he felt it giving out. That's because bars have 6-8 layers of carbon and they likely aren't all going to crack due to the same impact.


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## GRPABT1 (Oct 22, 2015)

sissypants said:


> I have thousands of miles on $15 carbon bars and never broke one. The #1 reason people break them is because of overtightening brake lever mounts, shifter mounts, and lock-on grips. I've seen four bars that broke this way. The #2 reason people break them is because they want to ride them at some funny angle which the bar wasn't designed to run at. If you mount them centered and with backsweep going back (not up) you should be just fine. Carbon is a unidirectional material, so you take advantage of its properties by installing it correctly and not crushing the fibers.
> 
> And I should add, if something breaks, you usually have plenty time to respond. One guy who broke his after a crash said he felt it giving out. That's because bars have 6-8 layers of carbon and they likely aren't all going to crack due to the same impact.


You must spread some reputation around....

Bang on mate. That said, it's surprisingly hard to get it wrong. I've never used a torque wrench for grips, brakes and shifters despite knowing that I should. I do however swear by fibregrip, this allows much less torque required.


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## sissypants (Sep 7, 2016)

GRPABT1 said:


> You must spread some reputation around....
> 
> Bang on mate. That said, it's surprisingly hard to get it wrong. I've never used a torque wrench for grips, brakes and shifters despite knowing that I should. I do however swear by fibregrip, this allows much less torque required.


Lol you'd be surprised how easy it is for some people to overtighten stuff. After all your allen wrench is 7 inches long, so why not grab the end with five fingers and push it around in circles until your biceps give out?

I haven't used a torque wrench either, but it would be a huge money-saving investment for tightening gone wrong.


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## RS VR6 (Mar 29, 2007)

If you're building the lightest bike possible...yes. If you're on a ~30lb bike...probably not.

I'm running a carbon bar on my XC and trail bikes. Both Enve bars...stem bolts torqued to 4nm. I've got a P6 Hiflex on my XC HT. I do feel that it rides a bit softer than the Thomson I had before. The Thomson felt like a jackhammer.


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## Jayem (Jul 16, 2005)

Strength to weight ratio is much higher, so on my AM stuff I run a DH carbon bar, it doesn't take as much mass to end up with the same strength as alloy. There will always be companies that take it too far, usually less reputable ones. It's not going to suddently crack and let go on you, a catastrophic overload failure of either is going to absorb an immense amount of energy in the process (meaning it's typically in a bad crash it'll absorb energy rather than transferring it to you). An under-load failure can happen with both and is the result of a flaw, corrosion or localized damage. This can cause a crack or delamination that will grow with cycles and it will suddenly fail at some point, not bend, even if it's alloy. I'm not even getting into fatigue here because that is rarely a factor. I'd say most frame failures are the under-load type, but for handlebars the overload is probably more likely given how it will stick out during a crash to "catch" the ground or whatever is in the way.


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## Schulze (Feb 21, 2007)

I've had the worst experience with carbon seatposts and saddles on a hard tail. So unless you're on a fs I'd recommend aluminum seatposts and ti or steel railed saddles. It sucks riding 10 miles with nowhere to sit.


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