Carrera gryphon v spec mech hanger issues.

[Renegade Rabbit]

Hi there!

I'm a newish Deliveroo rider, for those who haven't heard of it, it's a fast food courier business. They have people on push bikes and mopeds picking food up from all sorts of different restaurants and they deliver it to a customer's door.

I'm currently having issues with my carrera gryphon v spec's mechanism hanger, the issue is, the bolts holding it in place have completely sheerd off leaving small threaded pieces of metal in the holes, there seems no way of getting them out so I can fit new bolts.

I'm at my wits end with this issue, I've already lost several shifts to being without a bike! Any help is greatly appreciated!

 

[Renegade Rabbit]

 

[Crackle]

There's a previous thread which may help you.

https://www.cyclechat.net/threads/gear-hanger-for-carrera-gryphon.181692/

 

[Renegade Rabbit]

Thanks, that's the thread that brought me to this site via Google, I already have the mechanism hanger needed and I have a reliable source for new ones.

The problem I'm having is the leftovers of bolts that are stuck in the threads.

 

[Cycleops]

You’ll have to chip them out with end of a small screwdriver or pick. If whole it’ll need a drill. If you’re not confident doing it ask your LBS.

 

[biggs682]

oh dear that could get messy , if you get it wrong so good luck

 

[Ajax Bay]

Unless you already have a tap for the correct thread dimensions, you are probably better getting this done by your LBS. And if you do have the tap, you'll know what you have to do.
To fit the new hanger you've already got, you'll need the correct stubby little countersunk head screws.

 

[screenman]

For what you have lost in earnings the bike shop would have done the job a few times, speculate to accumulate.

 

[themosquitoking]

Is there anything of the bolts sticking out from the other side of the frame? If so you may be able to get some pliers on them and twist them out. If not take it to an expert with the right tools immediately. Then get a spare bike, secondhand, for around £100 so you don't lose a shift again..

 

[Tangoup51]

You should try drilling them out from the opposite side the bolt head was located. - The act of a clockwise spinning drill-bit biting against the other end of a clockwise thread will probably engage the bolt to turn with the drill bit and unthread outward.

For that, you'll need a small enough drill bit that does not engulf the entire bolt.

but this won't work if the bolt is badly chewed up, as it'd just simply get jammed and stop turning. - You might want to tidy it up with a hack saw or a metal file before you start.

 

[Ajax Bay]

this won't work if the bolt is badly chewed up

Have you looked at the 2 images in the OP?

 

[Tangoup51]

Have you looked at the 2 images in the OP?

Yup can only see one bolt that might pose a problem with my method; hence why i said "you might want to tidy it up with a hack saw or a metal file before you start." can't really see alot given the pictures.

 

[Renegade Rabbit]

Thanks everyone for all the help, I don't really have the required drill set for the job, I'll have to bite the bullet and go down to the shop with it, at least I have a temporary replacement now so I'm not missing work!

Thanks again!

 

[Ajax Bay]

my method

For the avoidance of doubt, I agree your method would work and it looked to me that, without any hacksawing/filing preparation, all three sheared bolts might come out but probably leave compromised threads needing further clearing out before bolting the new hanger on.

 

[Tangoup51]

For the avoidance of doubt, I agree your method would work and it looked to me that, without any hacksawing/filing preparation, all three sheared bolts might come out but probably leave compromised threads needing further clearing out before bolting the new hanger on.

Sadly yes, that is true it can damage threads (thats what happened to me on some occasions doing this method) but, sometimes there's enough left to make it work.
Really, only advise that method for threads that aren't structurally important.