I was cleaning my bike earlier and noticed several little cracks in the rim next to the eyelets on my rear wheel – front rim is still perfect. They could have been cracked for a while in theory but I have a keen eye and I'm sure I would have noticed. Do I need to bin this rear rim immediately or is it not that big of a deal. 😕

I must add that I only use the bike for light XC stuff and the wheel has not been abused.

I'd consider buying a new wheelset but the front is sweet so having a new rear wheel built seems the sensible option. Seems pointless doing that if the rim will fail at the eyelets again, though. Is the XC717 rim prone to this problem too?

Thanks in advance…

happened to mine eventually. I bought a new rim and swapped it over myself. Pretty easy and xm317s are quite cheap.

Pics?

Are the cracked ones located in a particular area? Could be that the wheels been over tensioned in places or even run at too high pressure (depends on the type of cracks)

The wife runs 317s on her bikes and I've just done a hub swap for her and she's kept 5 year old 317 rims on one bike and even older on the other. Possibly original 317s so they are capable of lasting.

It might fail gently, it might fail catastrophically. Do you feel lucky? I'd swap the rim or demote the wheel to commuting duty.

I'm sure I read somewhere that this suggests the spokes have too much tension.

Did you buy the wheel built up, or was part of a bike build?

just the excuse you need to buy some blingingly expensive new wheels isn't it?

Certain Mavic rims do this, don't think I've seen one fail before it's been caught & replaced, I'd be warrantying/replacing with a different rim myself.

New rim time, it happens eventually. Might be quite nasty if it goes at high speed I've had a rim fold in on itself at low speed and that hurt

I've run them like that for ages in the past. Had the first one fail recently (I've recently learnt to encourage my wheels to leave the ground 🙂 ). One of the cracks just got bigger, so you could feel it with your fingernail. I'd probably been riding it like that for a while to be honest. Keep riding them – if you only do XC stuff, what's the worst that can happen? – an exrended walk home I suppose……

Definitely don't use it for commuting – higher tyre pressures could cause it to crack more and faster. I've had a sidewall go before (which started off as a wee crack) – instant blow-out on the front. Glad I wasn't on the main road!

I'm sure I read somewhere that this suggests the spokes have too much tension.

Did you buy the wheel built up, or was part of a bike build?

The wheels were stock items on my XTC composite which I've had from new. They haven't been tampered with in any way and still run true as it only gets used for light duties. I do normally run my tyres at around 55psi which doesn't seem excessive.

They've done a few miles now and I guess the rear is under a lot more stress than the front so I suppose I've had my money's worth. I guess I'll either have another wheel built to match the front or go for a new set. 😀

Mavic rims normally have a 2 year warranty. How old are they?

Hairline cracks usually caused by over tensioned spokes. Also what size tyres are you running? Mavic 717 rims not warrantied if you use bigger than a 2.1 tyre for example, not sure what max tyre width is with a 317.

I spotted a couple of these cracks on my rear 717 – Just going to ride it till it breaks.