Carbon Bars - Replace after a crash?
- Thread starter SDA
- Start date
Nautonier
Eats Squid
Messy, but I think it could have been a lot worse. Bars are the one thing you really don't want to give out and you've got every reason to not trust carbon again.
Personally I think bars should be able to take being knocked around a little, I mean, if we're trying to improve our riding, we all have the occasional crash don't we? To replace bars or lack 100% trust in your gear every time you stack is completely suboptimal.
I'm going to keep the carbon bars on my trail bike, but have ordered alloy bars for the big bike. This thread has cost me money...
hungrytiger
Likes Dirt
Keith Scott had it right. No rally cars use a carbon fibre chassis. MTB's are the rally cars of the bike world.
https://m.pinkbike.com/news/first-look-banshees-2016-lineup.html
https://m.pinkbike.com/news/first-look-banshees-2016-lineup.html
Flow-Rider
Burner
My brother broke a set of steel handle bars back in the days of dragsters and his chin smashed straight into the stem then spilt open. Even steel breaks if you miss treat it too much.
moorey
call me Mia
We all see what we want to see. In almost 20 years riding, numerous of those racing DH, I've seen 4 sets of bars snap clean off. All have been in last few years. 3 were carbon with no warning and no apparent prior damage. One was a 10+ yo set of alloy bars on an old clunker at KOB this year.
I personally bent numerous sets of alloys back in the racing days. All pro-tapers. All survived the race/day out after horrible stacks.
I know someone else will have exactly the opposite experience to me. That's fine, run your carbon. I'll pass. Virtually identical story with cranks, btw.
I personally bent numerous sets of alloys back in the racing days. All pro-tapers. All survived the race/day out after horrible stacks.
I know someone else will have exactly the opposite experience to me. That's fine, run your carbon. I'll pass. Virtually identical story with cranks, btw.
Oddjob
Merry fucking Xmas to you assholes
So why is everyone buying carbon framed mtbs?
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Nautonier
Eats Squid
It's a fad. It'll be over soon and everyone will be back to chromoly.
moorey
call me Mia
Bamboo, or nothing.
Nautonier
Eats Squid
Bamboo = more compliance than carbon = less need for fancy suspension
Mr Crudley
Glock in your sock
Can be re-marketed as aircraft quality materials for your humble bike.
hungrytiger
Likes Dirt
Because they are mugs?
scblack
Leucocholic
While I said way back that I would happily ride those bars, on my MTB I have only ever used alloy for bars, stems, cranks. Carbon in those items does not give much advantage over alloy I think. And certainly not at a value I'd generally be happy to pay for a DH bike that's going to be crashed by a hack like me.
Mywifesirrational
I however am very normal. Trust me.
I know its roadie orientated, but still very topical to this thread.
Just not going to hang 5kg off the end of my carbon bars and drop them.
[video=youtube;0stL5Q9b_oo]https://www.youtube.com/watch?v=0stL5Q9b_oo[/video]
Just not going to hang 5kg off the end of my carbon bars and drop them.
[video=youtube;0stL5Q9b_oo]https://www.youtube.com/watch?v=0stL5Q9b_oo[/video]
Nautonier
Eats Squid
Good to see a test like that. Different findings to the one Enve did though - their alloy bar snapped well before the carbon one on the drop test.
But I think I agree wholeheartedly with the majority of comments on here; carbon is fine for XC and trail bikes, but if you're riding DH and potentially having some big offs, then alloy may well give you more peace of mind.
Loving my new Spank Vibrocores, there is definitely some carbon-like dampening going on there and they're actually pretty light at less than 80g more than my carbon bars. I'd have to say the dents/creases from the stem clamps, brakes, grips and bars when I took the carbon bars off were somewhat disturbing, not to mention the scoring from the brakes rotating on the bars. If I didn't trust them before I certainly don't now...
Mywifesirrational
I however am very normal. Trust me.
I am not convinced as to the scientific merits of this test, but I am not an engineer or know much about materials. But I know science.
Alloy vs carbon bars in this test, had a completely different profile, the flat aero bar cross section is completely different to the standard round alloy. Did they test alloy vs carbon or round vs aero bars?
The alloy bar was also fucked post test (?) it looked warped, so the alloy bar also 'broke', depending on how they defined broken.
I'm happy with the renthal carbon fatbars on the AM, DH and XC bikes. No one in the extended riding group has had problems with any brand carbon bars. But I run alloys on the DJ bike, I'm big and figured a frequently cartwheeling bike, alloy 'may' be more appropriate. I also run a heavy alloy bar on the CX bike, as I am not sure light weight carbon road bikes are great option for jumping, and my CX bike is rated to 15cm high drops - whoo! Also snapped the last road stem jumping water bars on a gravel road, so now I use MTB stems on the road and CS bikes...
The last bar I 'retired' was a 350g alloy RF atlas bar after some significantly deep gouges in the alloy, if a bar is going to brake, I'm not sure material matters.
Need a wealthy RB'er to buy all the bars and take them to a lab at a local uni and let the PhD candidates break shit, gouge and break them... Preferably someone who knows nothing of bikes, so they are blinded to brand names and expectation.
.... research funded by Enve Composites (or Spank ?)
ForkinGreat
Knows his Brassica oleracea
What stems for your road bike and CX do you use? I was looking at Easton EA90 for the roadbike. Currently using EA70 but wanting a different degree rise
Mywifesirrational
I however am very normal. Trust me.
Well, the bad news is it was an EA70 I broke, that stem had a hard life, at least the carbon forks didn't shear off.
Strangely I love EA70 bars, using them on the CX bike, not light, but feel pretty solid.
Currently using Thomson X4's, mostly as CRC had them for 80 each on special, then with the -$40 off caper a while back, I got two of them for 60 each. From memory only about 30-40g heavier than an EA70 but noticeable stiffer, which is awesome when sprinting out of the saddle from a sudanese teenager in hot pursuit with a large screw driver in the lovely suburb of Laverton.
Maybe he was just after a draft from a larger fella...
Jim Junkie
Used to sell drugs, now he just takes them
Now that would be a thesis worth doing
.The gouging is an important part as well because if my memory of fracture mechanics serves me correctly, the gouges would become stress concentrators. Basically the same reason sharp angles are not good in high stress areas and rounded curves are used, the sharp point will act to concentrate the stress and start a crack. Once the crack hits a big enough size or stress applied, you get catastrophic failure.
Purely for that reason, I would be retiring a bar with gouges like OP's in it. You've taken a nice smooth rounded surface and added a nice tight angle in it, right around where the maximum stress would be anyway, effectively multiplying the stress at that point.