Rear wheel rim problem

[Wayners]

Hi all.

My rear wheel rim has a section about 300mm long where there is a ½mm grove and I can pull out aluminium wire.
Is this a manufacturers fault?

See grove

This is what I've pulled out with my finger nail



Anyone seen anything like this before?

 

[thelarkbox]

Rim brakes? does the rim appear excessively worn? whats the front wheel condition?

how old is the wheel?

Not seen the likes myself?? the pics a bit blurey is it stranded wire? or perhaps a more structural piece of the rim itself?

If necessary relacing a wheel is a doddle thanks to a couple of 10 minute youtube vids and in my limited experience of 1 x wheel build amazon prime next day delivery and no quible returns made time the only factor in getting the right size spokes.

 

[sjpt]

Many rims have wear strips that look somewhat like that. When the wear strip becomes invisible it's time to replace the rim.
It may be your wasn't that well made, and that the wear strip is mostly worn away but the bit left has degraded.

 

[chris_n]

If the rest of it has no groove you are on borrowed time .

 

[saneagle]

The black groove is there to tell you when to replace the rim. When parts of the groove disappear because the bits either side are worn away, it's time to replace the rim. Yours looks Ok at the moment, though it is obviously wearing, so keep an eye on it. The bit you pulled out is just a bit that's peeled off the worn edge. It's nothing to worry about.

 

[Wayners]

Ok. I think it is a little worn out then. 2500 miles on it and I bought nearly 2 years ago. The front wheel has the same milage but doing much better and less wear.

 

[AndyBike]

Ok. I think it is a little worn out then. 2500 miles on it and I bought nearly 2 years ago. The front wheel has the same mileage but doing much better and less wear.

So youre a rear brake dragger then. But 2500 is ok, its paid its due.

 

[Wayners]

Yeah.
Not sure why back brake is doing the damage though.
Going to switch kit to another bike with discs at some point. See if that works better

 

[sjpt]

Some of the most efficient (from the point of view of breaking) rim brake pads also cause the most wear.
Also, if the rim wear and the issue you pointed to at the start are much more on one side of rim than the other it may be that your brakes aren't correctly adjusted.

 

[guerney]

My present rear wheel rim had a wear indicator line. I can't remember if it's now the ridge in the middle, or the groove below it.

 

[matthewslack]

That upper set of marks looks suspiciously like a hole to me!

 

[guerney]

A shadow from a Schwalbe Marathon Plus tyre rubber fang? Round 2 of spot the rim wear indicator line:





The first photo was my phone's camera focusing through a jeweller's loupe, also how I took this pic of my exact likeness which miraculously appeared in a microwaved carrot top the other morning. It even had fangs. I am become Jesus! Will my bike now float on water? I should attempt that wine trick again.

 

[saneagle]

My present rear wheel rim had a wear indicator line. I can't remember if it's now the ridge in the middle, or the groove below it.


View attachment 61017

Death would be imminent.

 

[saneagle]

View attachment 61020

He knows.

 

[kevsbike]

So how do you know if a wear indicator line has never been there or simply disappeared due to rim wear? Can't say I ever noticed one on my cargo bike wheels, which are incredibly sturdy, although I had thought about fitting hydraulic brakes just to be on the safe side.

 

[guerney]

He knows.

Nothing exists.

Death would be imminent.

Has been for months and hundreds of miles, looking pretty much the same. It was cheaper to buy a whole new rear wheel from the amazing BankruptBikeParts than it was to buy a replacement rim, so I did...

So how do you know if a wear indicator line has never been there or simply disappeared due to rim wear? Can't say I ever noticed one on my cargo bike wheels, which are incredibly sturdy, although I had thought about fitting hydraulic brakes just to be on the safe side.

...but the "New old stock" wheel's rim doesn't have a wear indicator line. Periodically take measurements? If the rims wear concave, @Sturmey suggested holding wire or spoke of known width against the rim while measuring, and subtracting wire width.

 

[saneagle]

Nothing exists.




Has been for months and hundreds of miles, looking pretty much the same. It was cheaper to buy a whole new rear wheel from the amazing BankruptBikeParts than it was to buy a replacement rim, so I did...



...but the "New old stock" wheel's rim doesn't have a wear indicator line. Periodically take measurements? If the rims wear concave, @Sturmey suggested holding wire or spoke of known width against the rim while measuring, and subtracting wire width.

Get yourself some superstrong snips, bolt croppers or a Dremmel with cutting disc. Cut out a section of the rim from top to bottom about 3 inches long. Look at the edges to see how thick the aluminium is. If it's too thin, buy a new rim and know that you saved your life. If it's as thick as new, buy a new rim and get many miles of safe riding. Either way, you get a happy outcome. QED.

While you're at it, get a sledge hammer and smash your motor until you can see the nylon gear inside. Have a look at it to see how worn it is. If it's too worn, chuck what's left of the motor and get yourself a rear hub-motor to enjoy thousands of miles of happy ebiking. If it's not worn, see if you can glue the bits back together with some JB Weld, otherwise chuck what's left of the motor and get yourself a rear hub-motor to enjoy thousands of miles of happy ebiking. Either way, you get a happy outcome.

 

[guerney]

Get yourself some superstrong snips, bolt croppers or a Dremmel with cutting disc. Cut out a section of the rim from top to bottom about 3 inches long. Look at the edges to see how thick the aluminium is.

I intend to saw through it and measure, when I get around to replacing the wheel.

Looking at my purchase history, that rim hasn't changed much since January. I've avoided using the rear brakes for months. What's suprised me is the number of bone jarring potholes that rim has bounced over without breaking. Yet another beneficial effect of my intermittent fasting weight loss regime.

 

[Sturmey]

I have experienced rim failure on a number of occasions. In all cases, I got a warning when braking from the brake lever pulsing due to the rim bulging outwards in one spot. In all cases, I just let some air out and the rim got me home. The place where the rim is joined, usually 180 degrees opposite the valve is a vulnerable place. I have on one occasion had a rim failure before the groove wore away. Some people claim that the groove actually causes a weakness in the rim. The Ryde/Rigida rims that I like have no groove but holes appear when they are badly worn but I have seen them bulge out before this.
I have attached an old magazine article below with one suggestion to test rim by over inflating but I think this can damage modern lightweight rims. Perhaps try over inflating only a little extra, say 20psi extra to test and then let the pressure back down to normal.
By the way, I have just worn down a 160mm brake disk from 2mm to 1mm (I read somewhere they should be replaced at 1.5mm) after 19,000Km, so they wear out too, but much less often and are much easier and cheaper to replace. ....The pleasures of cycling in the hills....