Rear Rim cracked around spoke hole

[Mycroft]

as the title says

I only noticed because Of an unrelated punc*ure, there are 2 cracks/splits on either side of a spoke hole in the aluminium of the rim.

so

Is it safe to go on riding? (managed 35mph on it at the weekend)

its a Alex CA-20 on a Marin Muirwoods 2009 and I can't find any way to buy another, so whats my best option for a new rim?

I'm wondering if I should rebuild the wheel myself once I've bought a new rim, but as I have never done anything like that before, would I be better off getting the LBS to take my money and do it for me?

the bikes only just over a year old and this has happened AND the bottom bracket has started to grind worringly.

Should I just hand the whole thing over and get a thorough repair/service?

how much is all that likely to cost (more of less) ?

thanks in advance

 

[accountantpete]

I'd deduce that this is the rear wheel?

It needs replacing as if it goes any further the spoke will become loose and put more pressure on the spokes either side etc leading to possible failure mid-ride.

Building a wheel takes a bit of practice and patience and some of the cheap hubs are not going to last long anyway so I'd look at a new wheel as being the best option.

The BB probably needs a service at least - although it may need replacing as again some of the components are not too hard wearing.

Personally I'd advise having a think about servicing your own bike - it's not too difficult.

 

[Matthames]

Is the bike still under warranty?

Cracks around the spoke holes are usually a sign that the spokes have been over tightened.

Is it safe to go riding on? The answer is a resounding no, a cracked rim will fail catastrophically, throwing you from your bike.

 

[Mycroft]

Rear wheel yup (sorry should have said)

bike about 4/5 weeks out of warranty (typical int it)

thanks for the replies guys I've been and done my shopping today on it, and decided that although I COULD do it myself, I just wouldn't feel confident in my own work (wheel building), so I'll be calling the LBS.

I think if it was the BB or the wheel alone, I might have a go, but I'm just not interested in what I perceive as "stress" at the mo.

I'm very grateful for the feed back though, a cracked rim isn't something I've come across before.

 

[andrew_s]

Is it safe to go riding on? The answer is a resounding no, a cracked rim will fail catastrophically, throwing you from your bike.

If it's a crack from a spoke hole that heads towards the adjacent spoke, it's not a serious problem. All that will happen is that the spoke will lose tension as the nipple starts to pull through, and you'll get a wobble in the wheel that you can't do anything about.

The dangerous cracks are those that form in the rim sides due to the brakes wearing the rim away.

 

[Mycroft]

If it's a crack from a spoke hole that heads towards the adjacent spoke, it's not a serious problem. All that will happen is that the spoke will lose tension as the nipple starts to pull through, and you'll get a wobble in the wheel that you can't do anything about.

The dangerous cracks are those that form in the rim sides due to the brakes wearing the rim away.

ahh. thats the kind they are, 2 cracks going towards the other spokes, under 1 cm but i now notice a 3rd one, so its LBS today

 

[e-rider]

Yes, this happened to one of my mavic rims. IT IS NOT SAFE TO KEEP RIDING. When I noticed mine it had occured around 5 different eyelets so the wheel was close to collapse!
The causes are:
1. using narrow, higher pressure road slicks on MTB rims (common cause)
2. excessive tension in the spokes, usually on the RH side (if more than one hole is cracked are they all from spokes on the RH side?); as a result or poor wheelbuilding.
3. a dodgy rim/wheel