How to tell if a rear mech is bent ?

Anonymous

Hey guys.

Wondered if someone could help me.

My last ride out I was blitzin along when I gets this long stick stuck in my derailleur, so I hops off the bike and I had to pull it out with some force, everything felt ok.

The next time I come to ride my bike its just not indexing correctly, usually this is fixed with a couple of turns of cable adjuster but the chain came off the largest cassette ring.

So I went about setting up the high and low stops and taking the slack out of the cable, what used to be a 5 min job was a 2 hour job and its still not perfect.

I am wondering if I bent my rear mech somehow when I pulled the stick out ? and I also wondered if there was a way to test to see if I had bent it out of alignment ?

I have gone up and down the cassette with the bike on the stand and in one particular gear it makes a racket and it dont sound right to me but maybe it is, so heres some pics to explain the gear its in and if this looks right:







I hope its not ruined its an XT one and not even 6 months old.

Any tests I can perform on this one ?

Cheers in advance.

The Rookie

Bent - new one time although the cages are in theory replaceable.

zx6man

Can you not just try bend it back. Mine was damaged at the knuckle so could never get it straight, that looks to be just the cage. I could tell better from the rear, the cogs should be lined up

Anonymous

Oh noooooooooooooooooooooooooo :?

Damn ......

Well, thank you for confirming that mate... am gutted... lol.

Maybe now is time to go single speed anyway.

Many thanks 8)

Anonymous

I'll give that a bash then ZX6Man, hopefully keep me running for now

zx6man

You will tho in BIG/BIG like that see it cross over quite severly.

Chunkers1980

Question is why did you "pull it out with some force" and not tease it out?

It's a precision part with many pivots.

Anonymous

I tried that for 15 mins chunkers and it wasnt havin it, was well jammed in there, rest of ride home was fine and it worked ok, but after a few days I get the bike out again and all is not ok.

Contemplating going 1 x 9 cant be arsed with all this, but its such a cost, I think I will just get a new rear mech and be done with it.

The Rookie

In that case keep the old one for Jockey wheels and other sundry bits you are occasionally very grateful for keeping!

Anonymous

I'm trying to convince myself I can fix this and its not bent, but am not doing a very good job lol.

I just took chain off this is what it looks like, just cant get alignment with the damn thing.



OK so I best order a new mech.

Anyone know how much am looking at if I was to go 1 x 9 ? just a rough cost ? does it have to be expensive ?

Chunkers1980

Looks like your hanger is not too striaght either. From 20 - 120 quid for the mech.

alfablue

Yes, the hanger is bent, why not try that first? £10-£12.

zx6man

Doesn't look like just the cage, that top jockey wheel looks well out. Hard to tell if its mech or even hanger (looks a bit out) .

.blitz

Agreed it does look bent

ime 9sp XT is ace when everything is perfect but it has zero tolerance to mis-alignment and sticky cables. I would take this opportunity to go 9sp SRAM which just keeps shifting and shifting and shifting until it blows up.

But nothing will work if the hanger is bent

Chunkers1980

What? and buy a new shifter too. He's already whinging about the price of the mech.

Chunkers1980

Oh and rubbish.

Anonymous

Ya never have much positive to say do ya chunkers ?

Right guys.. I taken some pics of the hanger and it does seem bent but can this amount cause something so drastic ?

I have the original hanger so am gonna bang that on and see whats what, god I hope thats all it is.

zx6man

Middle (of bottom 3 ofc) pic shows it best mate, could be a winner having a "spare" already. :-)

Anonymous

Yeeha am on it

Thanks everybody

alfablue

yes, that small bend could be responsible, as by the time you get down to the lower jockey wheel that would deviate quite a bit.

Always good to keep a spare hanger!

Chunkers1980

I think you'll find it is just the hanger than was bent. Doesn't have to be much and with the angle is magnified by the cage.

Positive? The guy was basically 'advising' you to buy something that wasn't needed and would not do as they say. I did not mean you were whinging as such, just that you said cheap fix and he was saying to buy a shifter as well as a mech to fix. A classic SRAM is more tolerable to bad indexing and mucky cables rubbish a few people spout on here, it grinds my gears ;-)

Anonymous

Well new (old/original) hanger on and looks like thats sorted it

I bought that red alloy hanger because it was red and would match the bike, but it is way lighter and appears way softer than the original one that came with the bike.

I am starting to learn the hard way that this weight weeny balloney is not all its cracked up to be, bullet proof even heavy parts have gotta be the way forward, only cost me about 1500 quid in mods to learn that lesson

When the bike is in the large chain ring and the largest of the rear cassette the chain does come off the bottom jockey wheel at quite some angle still, but its not grinding and making the noise like it was before, I'll have to compare it on a friends bike to see if theirs is the same.

All I have done is put the new hanger on and without any adjustment its already perfect up and down the cassette am that excited am gonna bang the lights on and take it for a spin.

Thanks everybody for their input today, I was this close to getting a new mech and it probably wasnt needed.

I'll confirm once more after test ride if am back in action, hopefully this post with pics may go to serve other newbies who may have the same problem in the future 8)

cooldad

CubeCrazy wrote:

I bought that red alloy hanger because it was red and would match the bike, but it is way lighter and appears way softer than the original one that came with the bike.

Strong is not better with hangers (as long as they are not made of butter). They are supposed to bend before the frame breaks.

CubeCrazy wrote:

When the bike is in the large chain ring and the largest of the rear cassette the chain does come off the bottom jockey wheel at quite some angle still, but its not grinding and making the noise like it was before, I'll have to compare it on a friends bike to see if theirs is the same.

You shouldn't be using big/big or small/small combos anyway - too much of an angle.

Chunkers1980

You do want hangers that are weak though, one of the very few places as it saves your frame. Perhaps if they do bend too easily they are a false economy, but it depends on the price of the mech you're trying to save I suppose.

I knew you'd come round to all this weight weenie stuff, I remember your upgrade thread around a year ago concentrating on the weight over anything else. Fit and forget and going for a good poo is much better and a more longer term time saving approach.

Anonymous

Well just got back from a ride, man the bike rides like new

So it was just a bent hanger afterall.

Interesting points guys on having a weak hanger to save the frame/mech, totally makes sense, I think the thing here is to always carry a spare, such a small light weight component you wont notice this in your rucksack, am gonna defo buy another.

Cooldad a friend of mine always rides round in the large chainring and I was always in the middle, I thought he was mad, so I gave it a go and I can go most places now in the large chainring, fitness has defo come on by it, but I will be sure to go into middle ring rather than large/large for a safer suitable drive.

Yeah I wasted a small fortune on carbon this, 150g that, wish I never had to be fair, even the wheelset wasn't worth 400 notes on this bike, still ya live n learn and i'll know for next time.

Am chuffed to be back on the trails and to think all it was, was a bent hanger :shock:

zx6man

Large/Large combo can supposedely wreck your chain in no time, as said, best to drop to middle and down a few cogs on the back.

Glad you are all sorted.

70\ʹspenguin

CubeCrazy wrote:

Yeah I wasted a small fortune on carbon this, 150g that, wish I never had to be fair, even the wheelset wasn't worth 400 notes on this bike, still ya live n learn and i'll know for next time.

Slightly going off topic but...

I agree the wheels were a bit overkill (crest/switch hubs would have been half the price for <200g heavier), but i dont think you "wasted" money or time on this bike. Ok you arent a racer and you didnt "need" any of it, but it got you on the bike more and riding a lot more also! I guarantee if you hadnt weenied the bike you wouldnt have enjoyed it as much. Now your fitness level is up you can see that the weight isnt as noticable, or needed, but i still maintain what you did was not a waste.

As for going SS, why not just go 1x9, stick a 38 up front and stay in a high gear for as much as you can. then, when you need the lower gears, you can use em.

Or as Mentioned on another thread on here, perhaps look into a CX bike instead - shiney new project......mmmmm new parts.

Anonymous

Yeah some good points there penguin

I am tempted to go 1 x 9 but so far not found out an idiots guide on how to do it, whats required etc, but I do look for info as and when I got time on here.

CX bike is that a cyclocross ? am always interested in a new project :oops:

Chunkers1980

Yep.

70\ʹspenguin

Remove front shifter
Remove chainrings
Remove front deraileur (unless you want it as a chainguide)
Buy singlespeed Chainring 38t
Put it on middle ring placing.
Buy shorter chainring bolts and bolt on ring.
Remeasure chain

Or just read this :P

http://www.bikeradar.com/gear/article/w ... ing-29342/

Anonymous

Thanks a lot guys, also thanks Penguin for the step by step I needed and the link, its bookmarked.

I can see 1x9 coming this way soon 8)