zaje

Last year I got second hand Ridley X-Bow; very nice bike compare to my previous heavyweight 25 year old MTB. One of the first things I did was wrapping a new handlebar tape. When I unwrapped the old one I discovered that the handlebar was welded at some time. It doesnt look that this has been caused by accident, in case of accident I would expect the damage on the outside, not inside of the drops. The handlebar feels fine, is not flexing and 5 months later is still fine. So my question is what problem handlebar had that it required welding?

JoeTBM 

It looks like there is also some pitting, possibly rust/corrosion repairs?

Is similar on the other side as well?

zaje

No, the other side is clean. The handlebar is aluminum, hard to imagine that it could rust in 5 years up to the point you need to weld it.

JoeTBM 

Well if it is aluminum, it wasn't rust, may just a defect during manufacturer but I still seeing some pitting indicating something caused it

Did you sand it or did you find it that way?

zaje

This is the way I get it, took a photo and wrapped the new tape over it.

Troul 

is there slag in the inside where you suspect it's been repaired?

zaje

I didnt check the inside, maybe when I will re-tape then I will try to get inside.

dsaul

That has clearly been welded or someone used some Alumiweld rods with a torch to fill in something. This was not a manufacturing defect or caused by corrosion. Possibly bent in a crash and cracked when they bent it back. Handlebars are cheap, replace them.

J.Higgins 

This is one of those peculiar unsolved bicycle mysteries that keep me up at night. Not really, haha, but I've seen some weird and funky things in my bike career.

I did a search for this bike, and all of the pics that I could find for this contained what looked like this particular handlebar. The bends and overall shapes all looked like yours, so its probably safe to establish that these are the OEM bars.

Questions:

Is the black coating on your bars actually paint, or powdercoat? It looks like really thin powdercoat to me.
Do you know the previous owner, or have you established enough rapport with the PO to ask them about this?

What this appears to be is the result of using low-temperature aluminum brazing rod to fill in holes, or a crack. Then the braze was sanded by abrasive tape using a shoe-buffing motion.

Did it roll off the assembly line like this, or...

Did someone try to make some sort of modification that didnt work? If so, what sort of mod would someone want to do in the drops like that?

We might need Jack Reacher to help us figure this out.

zaje

Hi, not sure about the crash causing this, the front part is perfect and both ends are symmetrical. asked LBS and they said that the corrosion might be caused by sweat, but that sounds like a bit far shot in the dark.

zaje

This will not be the case which keeps me awake during the night, I am just curious If that will bother me then at some time I will just buy new handlebars, checked local stores that the prices start at about 25euros, thats pretty cheap.

CliffordK

You didn't do the sanding either?

So, definitely a repair of some sort. As mentioned, there are some pits visible on the side.

I'm generally not putting a lot of force on my drops, so I'd probably ignore it if the rest of the bars appear to be sound.

Boroscopes are becoming more common, and might give some interesting info.

AeroGut

Handlebar corrosion to the point of failure is somewhat rare, but not unknown. There was a thread on here about one not too long ago, and a lot of folks from the hot and humid (ie sweaty) southeast US chimed in with stories. Although there are folks who claim that extended exposure to salty sweaty bar tape alone is enough to cause it, my personal opinion is that corroding to the point of failure or serious damage requires an additional galvanic component. More specifically, one mechanism is that the steel lever clamp has a sharp edge or bur on it and it is tightened to the point that the sharp edge cuts through the paint/anodizing/oxide layer and makes contact with aluminum metal. (Recall that even unpainted aluminum naturally forms a protective oxide layer on its surface. Chloride from sweat can eat through it, but slowly.)

Once you have contact between the steel and aluminum, then the clamp provides a good amount of surface area exposed directly to the corrosive salty sweat. Any oxidation of the surface of the steel ultimately results in oxidation of the aluminum metal instead because of the galvanic connection. A galvanic mechanism explains why you'd get excessive corrosion on one side but not the other, which is presumably just as sweaty. It also explains why excessive corrosion is not more common given the number of sweaty riders out there.

The good news is that the repair area doesn't show the characteristic white dust of aluminum oxide, suggesting that there hasn't been additional corrosion since the repair, though it might simply not have been ridden since then. If it were my bike, and I didn't know the person who did the repair, I'd replace the handlebar just for peace of mind, It helps that my local co-op has about a hundred handlebars to choose from for not much money though.

CliffordK

Toss one unknown used bar for another unknown used bar.

I'd be most concerned about the area from the brake clamp to the stem. The part around the clamp looks clean enough with the exception of a tiny silver patch.

It is possible that the previous owner rode almost exclusively from the drops, and thus corrosion impacted only the drops.

I kind of like the curves of those bars. Like many modern bars, they move the brake calipers up near the top. And, there is enough curve to get the hands in without any annoying crimps. Are the bar tops round or flat?

I've found a few good co-op bars, but they are few and far between.

zaje

I like the shape of the bars, they are really comfy to get into drops and can grab brakes easily. The rop is round.

wesmamyke 

Every shop I've worked for has at least one customer with pure battery acid for sweat. We had a guy that kept going through stems, the clamp ears just crumbled and broke off. I think he killed three of them while I was there, oddly no handlebar issues that I remember.

WizardOfBoz

Paint sanded away - poorly. Welding an aluminum handlebar. If you know the alloy (the bar is likely 2014, 7075 or another 7000 series) you can, with proper technique, do a weld but "hot shortness" (the welds tend to crack when they are hot) on other issues make it difficult. And if the post-weld heat treatment wasn't done properly (I think it wasn't: there's still origiinal paint on the bar) you could be looking at fatiigue failures already forming. Unless you are willing to be riding down the street sometime and end up holding the detached part of a bar in your right hand, I'd find another bar with similar shape and replace this one. And saw the original bar in half to prevent reuse. My 2 cents.

WizardOfBoz

BTW, the aerospace industry uses some pretty cool and weird welding technology to joine 2014 and 7075 aluminum for things like space shuttle fuel and O2 tanks. Look up friction stir welding. Welds the parts without melting them. Not appropriate here, though!

dabac

I've got a possible explanation, depending on how old that bar actually is:
BITD there was a manufacturer who made twist shift bar end shifters for drop bar road bikes. Those spots on the side could well be from the grub screw used to hold those from rotating. The patched holes could be from an attempt to combine bar end shifters with internal routing.

( have a pair of those shifters, but they're in "deep storage" and I'm not going to dig them out w/o proper motivation)

WizardOfBoz

Are internal routing holes ever cut on the ID of the bend in the bar? That's a high stress point.

cyccommute 

”Rust” is the term we apply to the oxide of iron. But aluminum, like most metals, can undergo the same reaction with oxygen to form an aluminum oxide…sometime called alumina.

Do not retape these handlebars! The handlebars should never have been repaired in the first place. They should have been thrown in the nearest recycling bin and they should be now. Broken teeth (or worse) will cost a whole lot more than a handlebar.

davidad

I am with Commute, you need to recycle and replace. Aluminum doesn't take well to abuse and has a finite life when flexed.