[Closed] Bent Derailleur hanger affecting front derailleur shifting??

they're independent - if you can' shift gears at the front the issue is with the front shifter, derailleur or crankset/bottom bracket.

have you changed the Bottom bracket and it's now wrong - bb axle length?

have you adjusted the high/low stops on the front derailleur at all?

Front derailleur could be twisted too - not exactly parallel with the cogs. Thre are various guides on pinkbike on how to do maintenance one of htem wen't into setting up a front mech so it could be worth a look before you go mad.

try this;

[url= http://www.parktool.com/blog/repair-help/front-derailleur-adjustments ]http://www.parktool.com/blog/repair-help/front-derailleur-adjustments[/url]

thanks for all the tips 🙂 Let me investigate! I think I need a new bottom bracket too, bit of a grinding noise coming from it :/

P.S. Bottom bracket has not been changed, and I have been playing with the high/low adjustments- I think I just need a cup of tea !

OK my dad has spent all evening at it following the video/parktool guides-its crazy difficult!

Its hard to get the derailleur cage adjusted so that it doesn't touch the chain when it is at the highest or lowest rear sprocket.

Also on rapid shifts down on the front derailleur going to the smallest front sprocket it falls off but I am trying to adjust this with the lower limiter. Crazy times!

Front and back are independent as said. If this has all worked before but suddenly went wrong there are some options. If it gradually deteriorated then some others.

In the middle chainring you should just about be able to get all 9 gears with no rubbing. In the biggest ring you will get rubbing on the biggest sprocket and v.v.

The falling off inside is due to the L screw.

If you're still stuck then post back.

thanks, I will have a look tomorrow- It has just started happening as the guy I bought it from said it was fine( it was shipped to me. Hopefully just the L screw now then. If its normal to rub on the biggest sprocket thats a big help too. Could I ask what v.v. is? Cheers!

vice versa right?!

hmm I adjust the L screw so it doesn't fall off the smallest cog, but it wont the move onto the largest....

[i] It has just started happening as the guy I bought it from said it was fine( it was shipped to me)[/i]

might have been useful information for your first post..., so it possibly never shifted properly - maybe the front mech is vertically in the wrong position?

Probably a silly question, but you mention the bike was (recently?) shipped to you - is it possible that the front mech got bashed in transit (or whilst preparing for transit, or unpacking for that matter) and has rotated a little on the seat tube? If the cage isn’t set straight, then it’s going to be an absolute pig to set up.

Alternatively, is it possible that the guy you bought it from is telling porkies and it wasn’t actually fine?

Or perhaps the guy you bought it from has a slightly different definition of “fine” to you?

yeah a fair point 🙂 It should be in the right position according to all the online guides.

I wanted to check something, the clamp on the upright has Deore on it but the part that shifts the chain is a FSA item- is this normal?! here is a pic:

[img] [/img]

yeah it must have been bashed in transit so I have been setting it up from scratch, lining everything up etc..

That front mech is bent. The outer cage has been pushed upwards.. Usually by the chain running up underneath it. The top bit, with the mega 9 sticker should be flat. Also, the pivots should be parallel to the chainrings. It might be twisted back a bit there too.
It'll take a careful hand to straighten it, but it's doable.

Looks like both mechs got bashed in transit 🙂

bikewhisperer +1

Did you note the box being bashed on arrival? If so the seller should be able to claim for the damage to the bike and give you the money to get a replacement front mech and rear hanger.

If not you may have bought it from a decent seller who would chip in on getting you a new front mech, they are only £18 from merlin.

cool thanks, making progress! Ok, quick question, do you need to match up all the front drivetrain components for things to work, e.g. have a FSA bottom bracket, a FSA crankset and FSA front deraileur? (I.e. could I use a XT front deraileur ?)

[IMG] [/IMG]

No you don't, I currently have raceface cranks a hope bottom bracket and a sram front mech all working fine together.

Your deore deriller would work fine with thoes cranks if it wasn't bent so badly out of shape.

Also from that pic it looks like you might have a cracked big chain ring 6 or so teeth round from the A of FSA

That's just a scratch on the ring.
TBH, those mechs are always a bit pants and prone to bending and rattling, and they're never as good again once you've straightened them a couple of times. I'd shell out for a conventional style (bottom swing) SLX or XT one and you'd be sorted.

Didn't rear half teh above.. but...

If you bend your rear mech cage in towards the spokes.. its possible to adjust the mech to work in some fashion, but, if your rear mech cage or hanger remains bent inwards then you could well have issues up front.

A bent rear mech/hanger will bring the chain line on the bottom of the front rings further inwards than granny granny woudl do on a perfect setup.. so, its entirely possible that it would cause the chain to get dumped off the smallest chain ring.

So, yes they are independent, but once you have the rear mech causing chain line issues, then the front absolutely will be effected in soem form

imo.

Also, i'd drop that front mech down a bit on the seat tube clamp as you may find that with the chain in granny, the mech is too high to work to keep the chain in granny.

+1 on the height of the mech - should be 3mm above the large ring. You can use a 3mm allen key as a guide.

Front mechs are a proper pain to set up - rear ones not so bad.

I make it a personal challenge to get as little chain rub as possible at either end of the cassette 😈

Thanks! You all have been really helpful. It looks like a crack but it is just a scratch. I think I'll just get [url= http://www.jensonusa.com/Front-Derailleurs/Shimano-XT-FD-M761-Front-Derailleur ]this[/url] if it fits as I am out in the USA for a while

Looks like it should work

it's just the front derailleur's being bent, if you straighten it or just get a new one it'll be fine.

Holy shit! $19!!! Yeah. that'll do the job.

great thanks so much all!

re: my previous post - apologies for the 🙂 I was on my phone and it shoudl have been a 🙁

apologies.

Damn it, I can't seem to post the video from pink bikes tech tuesday for setting up your front mech. Below is the link to it, i found it quite helpfull when i serviced my bike last.

http://www.pinkbike.com/video/159662/

If you can get that XT mech from Jenson for $19 it is a bargin.

Good luck, hope you get it all sorted.

thanks all 🙂

with a bottom swing (high clamp) one you might have trouble with that bottle holder bolt. Looks very close to the level that the clamp will be at.