Bent rear derailleur?

tboy823

hi

Boardman Team FS, Sram X7 10 speed rear derailleur.

I had a bit of a moment whilst riding in some local woods on friday.

Long story short, rear derailleur hanger snaps, chain and derailler end up in the rear wheel spokes.

New hanger fitted, but now the rear setup is really noisy, the gears seem to be indexing properly, but there is some 'slippage' like its hunting for gears that i don't want.

So i took it out for a short ride this morning and when looking down and backwards at the rear setup, it looks like the derailleur is slightly twisted so the bad noise is just the chain rattling thro' the 'not straight' derailleur wheels.

On closer inspection the frame, or derailleur don't look damaged or bent, so i'm thinking perhaps the gears will just need re-adjusting.

Any thoughts on this one as i don't really want to have to fork out for a new derailleur.

Cheers all

nicklouse

pics?

did you fit everything correctly?

inspect for where things are touching.

replace mech....

tboy823

Hi Nick

Thanks for the response.

I tried to take some pics but the best way to see it is by looking down and backwards when sat on the bike, my camera just won't focus on what i need it to because there's so much other stuff in the way!! I'll have another go tomorrow and see if i can get something worth looking at.

As far as i can see there only appears to be one way to fit it, there is some sort of adjustment screw that makes contact with a plate on the deraileur and a piece that stops the derailleur moving around too much, these seem to be in the correct position??

What things to i need to check to see if they are touching (or not as the case may be?)

I'm going to book the bike in with Halfords to get them to take a look, if the derailleur needs replacing, do you think they should do that under warranty? the bike is only a month old and only done around 80 miles!!!

thanks again

cooldad

Not if the mech got trashed in the wheel. 'Bit of a moment' not a warranty item.

tboy823

cooldad wrote:

Not if the mech got trashed in the wheel. 'Bit of a moment' not a warranty item.

I think i might not give them too much detail

Still can't get any decent pics

1mancity2

If the frame isn't bent and you have replaced and fitted the hanger/mech correctly most likely a bent mech.

When you go back to Halfords, you could say its always been like that and see if you get away with it.

tboy823

Ok very briefly as im just about to go out.

Took the mech off today and it all looks straight etc.

BUT
There is quite alot of play here.....

This is the gap......


This is how much it moves....

http://www.youtube.com/watch?v=3eZoT41U ... ture=feedu

This is how wonky it looks....


With some pressure is does seem to straighten.....

This is the chain going into the bottom wheel of the derailleur, chain on big cog on front and biggish cog on rear, so at the extremes but it shouldn't be this far out surely????


cheers for now

nicklouse

looks like a few issues.

1 needs the stops setting.

2 hanger may be bent.

3 mech may also be bent.

get it sorted.

cooldad

And looks like it needs tightening on the hanger.

The Rookie

cooldad wrote:

And looks like it needs tightening on the hanger.

+1, is that big allen bolt holding the mech to the hanger tight?

Simon

nicklouse

they often look like there is a gap but there is not as it is seated on the C clip.

tboy823

nicklouse wrote:

looks like a few issues.
1 needs the stops setting.
2 hanger may be bent.
3 mech may also be bent.
get it sorted.

Thanks Nick - in reply
1 which stops? high and low?
2 its brand new
3 it looks like it when its on the bike, but i can't see how when its off the bike, it looks fine?!?!
i wish i could!!

tboy823

cooldad wrote:

And looks like it needs tightening on the hanger.

The Beginner wrote:

+1, is that big allen bolt holding the mech to the hanger tight?

Yes, its as tight as it will go.

nicklouse wrote:

they often look like there is a gap but there is not as it is seated on the C clip.

I can see the C clip and it looks to be seated in the correct place, if it was seated tighter to the black 'washer', there would be no play?

supersonic

I'd take it to a shop. Looks like the hanger and mech are bent/twisted.

Limit stops - do you know how to adjust it?

tboy823

supersonic wrote:

I'd take it to a shop. Looks like the hanger and mech are bent/twisted.

Limit stops - do you know how to adjust it?

I'm taking back to Halfords tomorrow!! That should be interesting.

The hanger is new, how does the mech bend, it seems such a solid piece of kit?

Have you got a linky to a decent youtube vid for the limit stops please :?:

supersonic

The cage can twist easily.

Try Park Tools website - have a great guide for mech adjustment.

The mech might be bendable back into shape...

tboy823

Thanks for that,

if it is twisted, will it be really obvious when the mech is off the bike?

supersonic

No, usually can only be seen on the bike.

tboy823

supersonic wrote:

No, usually can only be seen on the bike.

OK

Oh well it looks like its down to the lads at Halfords then.

Cheers all

tboy823

So i took the bike into Halfords on Thursday morning for it's 6 week service. Had to phone them today to find out if it was done - and yes its ready for collection!!, couldn't get it today so i'll pick it up tomorrow.

Anyway, went out today and used a mates old Specialised Rockhopper and during one of our stops we were chatting about my derailleur problem and poking around the bikes we were on.

The pivot point of the drailleur and the hanger (indicated on the photo) should be spring loaded - yes??



Well when i took the derailleur off mine it certainly wasn't?!?!?

If it isn't, can the derailleur be set up properly, will it even function properly, and what could have happened to my spring loadedness????

cheers for now

i'll let you know it goes when i get the bike back.

tboy823

So i got the bike back from Halfords today and the good news is that the rear gears now index correctly.

But, it is now very apparant to me that the excessive play in the rear pivot point on the mech hanger is causing the derailleur to twist quite significantly.

I checked out a 9 speed X7 mech in the shop and it was all tight - and not sprung loaded, so to me it looks like there is a shim/washer/spacer missing from mine.

Can anyone shed any further light onto this one for me please?

cooldad

There are no shims, washers or spacers.

tboy823

Ok, but as this seems to be the root of the problem, what do you think can have happened for this excessive play to exist?

and can anyone think of any solutions???

thanks

supersonic

If it is working, then I wouldn't worry about. All my mechs have a bit of play there.