Rim Wear: How Worn Is Worn Out? Pics Included

buckmulligan

So I've been keeping an eye on my rear rim for the last 12 months or so, I know it's approaching the end of its life but when do you call it a day and replace it?

The wheels in question are Mavic Ksyrium Elites; the front isn't so bad at all, but the rear is looking more and more treacherous every time I look at it! :shock: I'm well aware that it's not cost-effective to buy new rims and rebuild these wheels, so it'll just be a case of binning it and buying a replacement.

I've had these wheels since late-2012, so they've served me well but where do you draw the line with regard to rim wear? Do Mavic rims from around this time have a wear indicator at all?

Front:


Rear:

ugo.santalucia

The rear is very bad... new wheels time...

Bobbinogs

Yepp, i would agree with that. Not worth risking a blowout as they can be very messy and are always an end of ride event. The obvious thing to do is look for someone selling a decent rear wheel...and then you realise that lots of people have a decent front wheel and not the rear. Throwing an excellent wheelset away when just a single rim is worn is the main reason I went down the handbuilt route...and have never regretted it.

meanredspider

How many people do most of their braking at the rear?

Garry H

How many people drag the front break?

ugo.santalucia

meanredspider wrote:

How many people do most of their braking at the rear?

In my career as a wheelbuilder I have replaced a rim or two... never seen a front wearing quicker than a rear. The rear wheel is always filthier than the front

meanredspider

I just hardly ever use my rear brake. Can't remember the last time I replaced the rear pads on the Volagi and I've never changed the pads on the Foil. Obviously a different story on the MTB

chrisw12

Bobbinogs wrote:

Yepp, i would agree with that. Not worth risking a blowout as they can be very messy and are always an end of ride event. The obvious thing to do is look for someone selling a decent rear wheel...and then you realise that lots of people have a decent front wheel and not the rear. Throwing an excellent wheelset away when just a single rim is worn is the main reason I went down the all my bikes have disc wheels...and have never regretted it.

Fixed it for you

But joking aside, the op is on the verge of something major happening on that back wheel, but had the sense to ask for adivice, how many people don't? In these days of health and safety regulations , I can't see why rim brakes are actually road legal....

bondurant

Yeah! Or tyres!

buckmulligan

chrisw12 wrote:

But joking aside, the op is on the verge of something major happening on that back wheel, but had the sense to ask for adivice, how many people don't? In these days of health and safety regulations , I can't see why rim brakes are actually road legal....

Well I've just returned from another 55 miles on it so I wouldn't say I'm that sensible :oops: But yes, now that I know how badly worn it is, I was a bit more concerned every time I hit a bump or pothole. Perhaps I should switch back to my winter wheels until I can source a replacement.

As for front vs rear rim wear, I certainly primarily use the front brake when coming to a gentle stop, but I suspect most of the wear comes from aggressive braking into corners where I use both brakes hard, and possibly subconsciously favour the rear. I agree that the build-up of dirt and grit can be much worse on the rear caliper and probably contributes significantly to the rate of wear, which is even more annoying because that feels very much as though it's preventable.

*SIGH*

Man Of Lard

meanredspider wrote:

How many people do most of their braking at the rear?

Me, ever since a "moment" in 1985 where the brakes failed to retard me at all coming down a hill towards a traffic-light controlled crossroads... The front brake suddenly bit really quite hard as I reached the stop line as the lights turned to red and I forward-rolled over the bars (still strapped in to the pedals) and came to a halt in a dirty puddle in the middle of the road.

Bobbinogs

I think the weather plays a huge part in rear wheel wear. I always brake on the front by choice but will also use the back when needed. The back wheel, in crappy weather, is always dirtier than the front...and the rear is needed more when wet front rims don't grip enough. So the rear gets used more in the wet...and it is dirty. Hence, accelerated wear.

OP, time to start a "What wheels" thread in RBA ☺

slowbike

I think I've got a rim that would replace that if you fancy rebuilding. The hub fractured during a ride and I've not replaced it - just kept the wheel incase the non-broken bits could be used for spares.
If you're interested I can get a photo and we can go to Pm

robbo2011

Don't use the rear wheel any more, it looks dangerously worn to me. If you can't affort to buy a replacement set right now then why not just replace the rear now and then the front in 6 months or so? There are internet sites that sell mavic front and rear wheels separately. Eg bike24.com

I have been getting worried about the rim wear on my ksyrium SL wheels which have done 27500 km, but after seeing your pictures, i see that they have lots of life still left as they are nowhere near as bad. Although i will replace mine well before they get to that state.

frisbee

meanredspider wrote:

I just hardly ever use my rear brake. Can't remember the last time I replaced the rear pads on the Volagi and I've never changed the pads on the Foil. Obviously a different story on the MTB

I only use mine if the front starts grumbling on a steep descent which I need to creep down because of blind bends or gravel. Never used it on a motorbike, except to trigger the brake light.

fudgey

I was behind someone on an audax last year when his rear rim exploded, sounded like a shotgun going off with the bang from the tube, i shat myself ha!

Anyway it took out about a third of the rim, was quite impressive - and a 7 mile walk for the guy. Luckily it happened on a slight downhill not the big one we had done just moments before.

itboffin

as everyone has said stop riding those wheels especially the rear, trust me when a rim splits whilst riding its never nice and could be seriously bad for your health

rolf_f

ugo.santalucia wrote:

meanredspider wrote:

How many people do most of their braking at the rear?

In my career as a wheelbuilder I have replaced a rim or two... never seen a front wearing quicker than a rear. The rear wheel is always filthier than the front

That is interesting! I always wear my front wheels out. I have two sets of Campag wheels with worn out fronts and serviceable rears. Maybe I need to look for all those folk who wear their rears out and make an offer for their fronts!

Perhaps it just means I'm better at cleaning my rims than everyone else!

I just follow Campags instructions and measure the width of the rim - if it is larger than it is meant to be I replace it (though by then you can feel it anyway under braking without measuring).

Matthewfalle

Even for a sketchy bugger like me that wheel is going straight in the bin. Seriously shot to bits.

Re f/r braking - I'l trail brake the rear but the front is the main one for stopping - same on the moto-sickle. You only realise how much you use the rear brak if you disconnect the cable then go for a spin - it's trail braking Andy all the really slow stuff, like plotting through traffic and stopping at red lights/hot chicks waiting to cross the road.

keef66

^ wot they all said

There's not a lot of metal in a Ksyrium rim to start with; that one looks to be at the point of failure to me :shock:

You're obviously a lucky bugger what with still being alive, so can I have your lottery numbers?

buckmulligan

Thanks for all the input chaps; looking at the rim profile below alongside my photo doesn't exactly inspire me with confidence :?



I guess I should probably retire it but it seems such a shame as I bet they're well under Mavic's claimed 1520g per pair now Maybe I'll take a hacksaw to it when I have a spare minute and see just how close it was to a full-blown catastrophe.

fat daddy

wow .... thats an awesome picture, I have never seen a rim that worn before (perhaps I haven't lived) ... no freaking way would I ride on that, that cant be far away from disintegrating

how many miles have they done ??

Bobbinogs

BuckMulligan wrote:

... Maybe I'll take a hacksaw to it when I have a spare minute and see just how close it was to a full-blown catastrophe.

Yeah, I did that with an old pair of Zondas as I was interested to know how much of a variance there was between measuring with sprung calipers (which simply cannot go perpendicularly across the whole brake track due to the internal tube bed interfering) and the reality (with a rim section cutout). The general guidance is caution under 1mm and replace around 0.7mm so, with the brake tracks tangibly concave and measuring 0.6-0.8, I figured it was time to get the hacksaw out. Turns out the min was actually about 0.8mm so I had at least another month of safe riding on those wheels. Never could work out out to stick the section of rim back in though

buckmulligan

Well Strava says that I've covered ~20,000 km (or 12,500 miles) since I've had them but there's a fair few turbo trainer "miles" in there too, so maybe 8000-10,000 miles at a guess? I try to keep my bikes reasonably clean, but they have seen their fair share of bad weather over the years. How many miles would you normally expect out of a half-decent alloy wheelset?

To be honest, I think Shimano's bloody awful stock-brake pads that came with my calipers were to blame for a good majority of that wear. They always used to make a horrible scratching noise under braking and I remember being alarmed at the wear to the rim after the year or so that they lasted; I switched to Swisstop after that and they seem a lot kinder to the rims as well as actually braking better.

keef66

It's impossible to generalise. I have a pair of RS10s which according to the visible wear indicators are still OK after 10 years use, 7 of those year round. Never used anything but stock Shimano brake blocks / inserts.

However, I only ride for leisure and all of it on quiet country lanes with very little braking. I don't do any stop-start commuting, I'm a relatively light rider, and there's not much in the way of hills round here so my rims have a pretty easy life. My winter / wet weather bike has full guards, which probably helps.

If I weighed 18 stone and commuted somewhere hilly and with luggage I'd probably have disc brakes.

rolf_f

BuckMulligan wrote:

Well Strava says that I've covered ~20,000 km (or 12,500 miles) since I've had them but there's a fair few turbo trainer "miles" in there too, so maybe 8000-10,000 miles at a guess? I try to keep my bikes reasonably clean, but they have seen their fair share of bad weather over the years. How many miles would you normally expect out of a half-decent alloy wheelset?

To be honest, I think Shimano's bloody awful stock-brake pads that came with my calipers were to blame for a good majority of that wear. They always used to make a horrible scratching noise under braking and I remember being alarmed at the wear to the rim after the year or so that they lasted; I switched to Swisstop after that and they seem a lot kinder to the rims as well as actually braking better.

The scratching is the metal embedded in the pad. I don't find Swissstops noticeable less prone than other pads for picking up chunks of alloy after wet weather. The solution, whatever pad you use, is to regularly check the pads for metal and dig the offending chunks out when found.

I'm sure most of my wear comes from the 10% descent to my house at the end of my commute.

Alex99

Bobbinogs wrote:

BuckMulligan wrote:

... Maybe I'll take a hacksaw to it when I have a spare minute and see just how close it was to a full-blown catastrophe.

Yeah, I did that with an old pair of Zondas as I was interested to know how much of a variance there was between measuring with sprung calipers (which simply cannot go perpendicularly across the whole brake track due to the internal tube bed interfering) and the reality (with a rim section cutout). The general guidance is caution under 1mm and replace around 0.7mm so, with the brake tracks tangibly concave and measuring 0.6-0.8, I figured it was time to get the hacksaw out. Turns out the min was actually about 0.8mm so I had at least another month of safe riding on those wheels. Never could work out out to stick the section of rim back in though

Send it to Campagnolo and see if they'll weld it back in Of you could sleeve-join it with something.

Matthewfalle

Smash it with a hammer and chuck it in next door's garden.

Or set fire to it with fire and turn it into a hoop of fire.

mugensi

BuckMulligan wrote:

Well I've just returned from another 55 miles on it so I wouldn't say I'm that sensible :oops: But yes, now that I know how badly worn it is, I was a bit more concerned every time I hit a bump or pothole. Perhaps I should switch back to my winter wheels until I can source a replacement.


*

I would change it sooner rather than later, a mate of mine had a rear wheel which looked in a similar state to yours, I said to him I'd lend him a rear wheel as his didn't look safe but he reckoned he'd get another few weeks out of it and off we went. About 45 minutes later I was riding behind him and he hit a sharp bump in the road and the rim obviously caved and buckled, the rear derailleur caught in some of the spokes and ripped it off breaking the hanger and taking a chunk out of the drop-out at the same time. Not only did he need a new wheel, he needed a new frame and RD also. It was an expensive mistake and a classic 'I told you so' moment.

ugo.santalucia

One of my customers and forum user managed to get to 0.3 mm on his H Plus Son TB14

Alex99

Matthewfalle wrote:

Smash it with a hammer and chuck it in next door's garden.

Or set fire to it with fire and turn it into a hoop of fire.