Good evening all, Just a quick question to all the more experienced riders..

[ayceejay]

Did you ever have that back wheel out Dave? It looks to me (Inspector Clousseau) like it is/was not seated properly, if I am correct this would create the bad shifting YS refers to. If I am correct and the shop installed it that way I think they should replace the whole bike.

 

[Racing roadkill]

No, but puzzlingly there's a lot of gunk on the jockey wheel - given the clean look of things elsewhere, I'm surprised at how mucky it is.

Having a closer look, that whole rear mech looks crash damaged. I'm wondering if the bike had been taken on any 'test rides' before the O.P. got it.

 

[Globalti]

There's a design fault there. You can see that the rear droput (the slot for the axle) is common with the derailleur hanger, an unusual design because normally the hanger will be mounted independently of the dropout and axle. I guess the reasoning of the designer was to have the clamping action of the quick-release (QR) give extra bracing to the hanger. However the hanger is made from a brittle crystalline alloy that is designed to snap sacrificially, saving your frame from more expensive damage. Look carefully at the hanger and you can see that it has several parallel marks on it made by the notches on the back of the QR nut, which are designed to grip down through dirt and muck and ensure the nut doesn't move around in the dropout. I would need to examine the setup carefully but I'd be willing to bet that something has caused the clamping action of that nut to press hard on the un-supported hanger and bend it or at least place it under tension, following which it has done its job and snapped, causing the catastrophic accident that has wrecked everything. It snapped exactly at the point where the bending force would be greatest. Possibly somebody tightened the QR while the axle wasn't fully forward in the slot, leaving those telltale parallel marks and bending the hanger inwards slightly as it was unsupported.

If that's not the explanation, the bike has fallen over and the hanger has got slightly bent and weakened. They are very brittle.

The plastic disc needs to be replaced on the spokes and secure; it's there to prevent the derailleur from contacting the spokes.

I wonder if @Yellow Saddle agrees with my diagnosis?

 

[w00hoo_kent]

I know a botched shift can be enough to do the mech, but I've only heard of it happening on climbs, and this doesn't sound like it was one.

I think I'd have been pretty vocal about expecting a bike to last more than 100 miles before something like this happened to it, especially when I was back in this position with my first C2W bike (Specialized Sirrus so kind of similar). If the bike hasn't been left unattended particularly (so third party damage is unlikely) and the shop built the bike up. I'd be very interested in their explanation of how it happened 'just so it didn't happen again' and considering their complete lack of goodwill on the fix I think I'd also be looking to friends for other recommendations for where to take it to next, and be sure to let them know that someone else will be getting my, likely to be ever increasing, workshop pounds.

 

[MichaelW2]

There's a design fault there. ... several parallel marks on it made by the notches on the back of the QR nut,

notching or scoring of the hanger would create a stress raiser and it would break off below it's design strength.
Can you post some better pics, taken in shade, in focus, not blurred, showing the broken face and the notched side.

 

[User16625]

That is not a warrantee repair. A hanger doesn't give away with age but with sudden overload. I've seen plenty of breaks like that and each and every one of them is due to a bothched shift. Perhaps the first bad shift didn't break the camel's back, but repeated use thereafter did. Soak up the cost, fix it, have someone show you how to shift gears and write it off to school fees.

What is a bad shift? To shift from one cog to another I simply press one of the gear levers. I apply low pressure to the pedals while doing this before going like **** again.
Sounds like one of the limit screws wasnt set properly and allowed his RD to shift too far, passing the rear sprocket and making contact with the spokes of the rear wheel.

To OP, were you trying to use a very "easy gear" when this happened?

 

[Racing roadkill]

What is a bad shift? To shift from one cog to another I simply press one of the gear levers. I apply low pressure to the pedals while doing this before going like **** again.
Sounds like one of the limit screws wasnt set properly and allowed his RD to shift too far, passing the rear sprocket and making contact with the spokes of the rear wheel.

To OP, were you trying to use a very "easy gear" when this happened?

A bad shift, is when you are in way to high a gear, and you try and down shift when you've already pretty much ground to a halt, and you are putting as much through the cranks as you can muster. The result is usually a loud cracking sound, possibly a knackered chain, maybe a shark toothed sprocket, and often a broken rear mech.

 

[Nigelnaturist]

@Dav091, sorry to hear of your issues, I get replacement saddles and wheels after 8 to 12 months if they fail (rims fracturing ect) so for a hanger to fail in two weeks is a warranty issue. If every R.D. failed after two weeks well the company wouldn't be in business.

That is not a warrantee repair. A hanger doesn't give away with age but with sudden overload. I've seen plenty of breaks like that and each and every one of them is due to a bothched shift. Perhaps the first bad shift didn't break the camel's back, but repeated use thereafter did. Soak up the cost, fix it, have someone show you how to shift gears and write it off to school fees.

In all honesty I suspect its more a fault in the casting, my cheap Viking has had more than its fair share of bad shifts over the seven years I have had ( and a fair few under a lot of stress on hills), so to say a hanger that fails in two weeks or so isn't a warranty repair I don't know, its like saying a spoke failing after two weeks isn't a warranty repair, or a sudden failure of a brake cable on your first outing down hill resulting in a trip in hurse isn't

. The only fly in the ointment could be that the argument may be, that someone parking their bike next to yours, may have caused the issue, you couldn't have known that, but they may say it's not their problem, likewise your RD could have been hit by an object, flicked up off of the road, you may not have thought anything of it, but again, they could argue, that's not their problem either. Personally, if I was the LBS, and the warranty route had failed, I'd do the replacement, as a good will gesture.

This you are likely to know about anything big enough to a damage a hanger is going to hit it with a whack of a force.

Over the years my bike has been dropped/fallen been in a few offs, the rear hanger along with the brake calipiers and folks are the only original thing on the bike.

I'd say overshifted and caught the spokes. Which shattered the mech hanger. Saving grace is the mech is about £25 and a hanger should be £15 max.

Most likely poor adjustment of the mech limiter screws, the shop should have checked. Big question - which retailer - if it's a biggy, they don't check, just put bars and pedals on.

Difficult to say as the shop never knows the use of the bike.

I don't know where you are riding but it sounds like a coastal path, not a Red/Black route MTB trail.

This in itself is a warranty claim, its like saying a synchro mesh on a car failing due to a badly sized shim and then someone braking loads of teeth off a gear (not likely I know), if you bought a car and something wasn't set up right and you killed someone.............. get the idea.

 

[Nigelnaturist]

A bad shift, is when you are in way to high a gear, and you try and down shift when you've already pretty much ground to a halt, and you are putting as much through the cranks as you can muster. The result is usually a loud cracking sound, possibly a knackered chain, maybe a shark toothed sprocket, and often a broken rear mech.

Suggest you got cheap kit then, only thing I have broke on the drive chain in 20,000 miles nearly is a front middle tooth, mind you it wasn't the best quality.

 

[Racing roadkill]

Suggest you got cheap kit then, only thing I have broke on the drive chain in 20,000 miles nearly is a front middle tooth, mind you it wasn't the best quality.

Yep, nearly all my kit is not what I'd call high end, I just make sure I can ride properly, it saves any embarrassment. I've yet to experience any bad shift damage.

 

[Nigelnaturist]

Yep, nearly all my kit is not what I'd call high end, I just make sure I can ride properly, it saves any embarrassment. I've yet to experience any bad shift damage.

Must make me a not so good rider as I get the odd one now and again in the 6,000 miles or so I do a year.

 

[Ticktockmy]

I am wondering if you tried to change through the gears to quick, forcing the Chain at too sharp an angle across the Cassette which applied sidewards pressure on the hanger, at least the Hanger did it job and saved the frame. Now just a quick job to remove the hanger fixing screw, pop in a new hanger, and fit a new derailleur. something your LBS should do very quickly.