These Shimano RS10 wheels came stock on my Giant, and the bleedin bike's only a month old!

I might have had hit a small tree branch, but I'm pretty sure I didn't, as it wasn't even in the part of the road I usually ride.

I'm still reeling of the shock of surviving a catastrophic front wheel failure with nothing more than 3 spots of road rash. No sprains, strains or fractures.

But my shifter and rear deraileur have superficial scratches.

The spokes pulled out of the rim eyelets. One of the customers at the bike shop took a feel of my hub spindle and said it felt really rough, possibly indicating that the hub had seized at that time.

Still, I'm furious. Sure I knew that Shimano R550/RS10 wheelsets were prone to spoke breakage issues, but I had never expected this to happen.

This is America. Sue that bike shop. Or manufacturer. Or something.

I'm not American. But I'm quite sure it's Shimano's fault. I'm getting this replaced under warranty through the bike shop.

Ouch!!! Yes, they do happen. I had a JRA in 1989 or so with my mongoose alta. I was JRA when my tiny freewheel bearings spewed all over the tarmac!

Pops and I had to walk up to a pay phone and call Mom to pick us up.

LBS that I bought the bike from didn't believe it either until he saw it, but considering my ignorance and lack of owned tools at the time, he recognized it as a freak occurrence and fixed me right up.

Oh, true. Singapore.. hmm.

No but really - I'm no expert, but a properly tensioned front wheel should not just randomly explode. and as far as I know front hubs don't randomly seize, either, not when they're set up correctly. This is, of course, assuming that you're sure that nothing got caught in your wheels. But if this is Shimano's fault (which I don't think it is), we're not talking warranty replacement, we're talking recall. I don't know enough from your post to make a conclusive and informed judgment, but I tend to suspect that something was definitely not set up properly.

I know.

^ gives new meaning to 'drope the hammer'

Beef, I respect your posts but this is a bit brunt. It is entirely possible that one out of probably tens of thousands of hubs fail catastrophically, an anomoly so to speak. Perhaps a bearing freakishly explodes jamming the others. I dont think this would require a recall it is most likely a one off incident, so yes were back to waranty replacement and since nobody was hurt (thankfully) life goes on....leave the laywers out of it

I'm not ruling out the possibility, as the road was wooded and would have falling branches every now and then. However, the fact that it and its predecessor R550 eat up spokes for breakfast makes me quite sure it's the fault of the whelset.

All you needed was one or two more zip-ties

Thanks. I was mostly kidding with the whole 'sue them' thing. Maybe it's just the human tendency to point fingers, but something just seemed fishy to me. No unusual load, no impact, smooth road, kerBLAOW.

But you're right, it's probably just a freak accident, I've had stuff mysteriously fail on me before (and sometimes it was my own fault). So I agree, if I were in the OP's place I'd just do the warranty thing as well and thank my lucky stars I wasn't hurt any further.

But if I smashed my head on the pavement and ran over a kitten and got paralyzed from the neck down, then of course it'd be a different story.

yikes. did the spokes poll out of the rim? is that what I'm seeing? theh spokes in the picture look good so if they pulled out of the rim i guess it would be a material failure of the extrution of the rim. crazy. JRA failures happen but that is wild.

mmm... straight pull spokes...

I would have thought shimano quality control would be better, at least you only need to head across the causeway to get a new set.

https://www.cyclingnews.com/tech.php?...heel_factory08

Sh1t!! That's a Dura-Ace crank, right? That is one of my worst fears.
Do you reckon it had anything to do with the sub-freezing temps in which you often ride?

That's one of your worse fears? I once rolled off a curb on a bike whose front skewer was loose.

That sucked. Fork into pavement, hands and face soon to follow.

I'm pretty sure that will never happen to me again.

I've seen a bar failure in a MTB race, that was pretty nasty. I'm going to pray that never happens to me.

Seems like a crank failure would be pretty tame...

My 2008 CAAD9 6 had 130 miles on it when the rear derailleur pulled a suicide maneuver into my rear wheel. Junked the frame, rear wheel, and half the drive train. The limit screws were properly set, hanger and derailleur straight as a whistle, and no apparent funny business in the chain. I wasn't shifting, and was in the middle of the cassette when the rear derailleur got caught. Freaky accidents do happen.

So I jogged from home to the site of the crash (technically, if you didn't 'crash' into something is it still a crash?) and retrieved 5 spokes and my cyclocomputer magnet.

It's surreal not just to be able to walk away from such a catastrophic wheel failure, but to be able to exercise later in the day!



All the spokes that had pulled through were bent. They look like they were compressed from the ends rather than struck by an object in the middle.



Took a look at the nipples and I got a rough idea how the rim failed. The flanges of the nipples that rested on the rim holes were tapered. Not to mention, unreasonably small for a 16-spoke wheel.

The taper probably acted as a chisel, progressively enlarging the rim hole and subsequently pulling through. These nipples are a new design and are also used on the RS20 wheelset. Shimano's technical drawings show that the previous generation R550 had nipples on the hub end rather than the rim end, with an oversized spoke head on the rim side.

I'm considering escalating this situation by contacting Shimano Singapore directly about what I have found so far.

Oh my gosh this is so fun! It's like Air Crash Investigation, complete with theories and crash site surveys except it's happening to me!

Sorry, mate, but it's really old news. Happened in summer. I think there was a whole thread on it... what else.

I've always considered Shimano stuff to be well-designed, down to the little details like metal tabs on my Deore shifters that were strategically placed to prevent crash damage to the shifter itself. I'm likely to chalk this incident up to an isolated case of poor design.

Too bad you don't have a cockpit voice recorder on your bike, so you could post the tape of yourself saying, "Oh s***!"

Do you have that JPeg hot linked to a keyboard command?

I think I would be having a much closer look at the bend in the spokes to see if there is any damage to the coating -- that, and have a look at the fork. If, as you say, there were branches on the roadway, there is a chance you flicked one into your spokes.

I don't see much of a taper, if any, on the nipples where they would rest inside the rim. What you see as taper, I think, is just the normal shape of the nipple where it goes from round to flats for the wrench, and they wouldn't have any influence on the integrity of the rim.

The fact that there ISN'T any taper on the seating surface might be a clue to what happened, though.

Coating's pristine, except for surface rust on one of the spokes (but this wheelset is just 1 month old!) Fork's surprisingly good, not even a single scratch from the spokes but there's gray where the tyres made momentary contact.

I would think that the branches of the size there would not have taken out 5 spokes at a go at 20kmh (I was just starting to accelerate out of a turn) even then.