How long should you ride a set of ali bars before you change them?

I usually change mine when I get bored of them and fancy something different.

When it has a deep gouge into them

Depends on the use and any big crashes.
I’ve had multiple fractures in one wrist from a set of Azonics failing BITD. My other wrist suffered lots of ligament damage. Took ages to heal, so after that I changed them every season. That was probably overkill. I do still treat them as consumables though.

I tend to look at the warranty length and go from there.

Most warranties seem to be 1year

If they last past the first year then they ain’t got a manufacturing fault.

I guess it goes back to what sort of life they’ve had.

I can’t think of anyone I know having bars that have failed to be honest.

I change mine when I want to try something new.

This has crossed my mind recently, when I realised I bought my set of fatbars second hand in 2015 and must have done 5000 miles on them since, including probably a combined month of uplifts and alps trips.

While there’s no scratches or any apparent damage, the bike’s been crashed dozens of times and many jumps cased. Fatigue failure does make me think whether I should replace it.

Out of curiosity, anyone ever seen any actual scientific data on handlebar fatigue limits?

You’re not going to fatigue handlebars. They’re good for millions and millions of cycles. For the small vibrations and small hits billions of cycles. If you can imagine the hardest hit possible without bending or yielding the bars then you’re into hundreds of thousands if not millions of cycles. There are factors of safety built into the material specs and in the actual designs so many layers of conservative design.

Clearly all this assumes a perfect material with no defects or other stress raisers, but from a material property perspective alone, they’ll be fine.

Depends what your doing with them

Rider weight
Type of riding
Type of Bars
how often the bike is ridden

I weight 11.5 stone and ive a set of X-lite Gforce DH bars (bar walls are about 3.5 or 4mm thick) on an XC bike that have been there for 20 years but now only get used a few times a year and Ive no plans to swap them any time soon

it just depends.

After you fluff a step down landing and there’s a loud cracking noise and before you push up for another go would be a good time😳

Not many things compare to the close call I had ~15years ago, when the left side of the drop bars suddenly sheared by the stem clamp, while on the way to work. They were ~7 years old. How I kept hold of the sheared drop to stop it swinging into the spokes, kept my balance and safely braked to a standstill from ~17mph was a miracle.

This has crossed my mind recently, when I realised I bought my set of fatbars second hand in 2015 and must have done 5000 miles on them since, including probably a combined month of uplifts and alps trips.

Personally I’d change them but as mentioned I’ve had bars fail so view the risk differently, £50 verses 6 weeks pay and getting to see your hand at an unfortunate angle.

It’s an old argument but failures have happened to old/damaged bars and it can sting.

Azonics

Guessing that was back in the day.

I presume bars are probably made better now then back then, but I’ve read it’s good to change them once a year if you’re a top racer, once every two years if regular rider.

X-lite Gforce DH bars

X lite bars used to fail along the etch of the big X. I found this out the painful way, 10 miles from home, so wedged a stick in there and put the snapped bit in the handlebar clamp and rode home more carefully..

Dammit, I’d just decided not to buy new bars and spend the money on something else.