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2 hangers in 2 rides...

concordeconcorde Posts: 1,008
edited July 2013 in MTB workshop & tech
Snapped a hanger last Thursday. Bike rode fine on the Tuesday, then rode on the Thursday and had to cut the ride short as gears were slipping and chain was coming off at the back on the biggest cog when climbing. One of the boys had a look and said my jockey wheel is really worn and the chain is sticking between the jockey wheel and the metal bit. Causing the mech to pull forward and chain come off.

Got home to find hanger was snapped. So I thought I'll change the hanger, that is what must have been causing it as it must have been bent. Changed it, rode it up and down lane and it seemed fine. Brother went out on it last night and it snapped in half again when he was riding up a hill. He said the chain came off once before this but couldn't tell me where it came off (i.e. biggest cog at back etc) as he is clueless.

So now I am thinking it could be the jockey wheel again but I've asked a few people and they've said jockey wheels can be worn beyond belief and cause no bother.

Thinking I may probably be better off just buying a new rear mech. SLX medium cage clutch mech instead of the long cage SLX I have now. And drop the big ring at the front...

Doing my head in!

I've been through 4 hangers in the last 8 months!
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Posts

  • Chunkers1980Chunkers1980 Posts: 8,035
    Sounds like a setup issue.
  • nicklousenicklouse Posts: 50,675 Lives Here
    chain suck.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • concordeconcorde Posts: 1,008
    Sounds like a setup issue.

    Care to expand...?
  • concordeconcorde Posts: 1,008
    nicklouse wrote:
    chain suck.

    I don't think it is chain suck, when it was happening last Thursday me and a mate had a look at it and the only ting we could see happening was the chain being jammed between bottom jockey wheel and the cage bit of the bottom of the mech. The bottom jockey wheel had loads of lateral movement, don't think that is the norm is it?
  • nicklousenicklouse Posts: 50,675 Lives Here
    you say the mech is being pulled forward.

    if it was jamming in the cage it would be pulled backwards. the only way for it to be pulled forward is chain suck.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • concordeconcorde Posts: 1,008
    nicklouse wrote:
    you say the mech is being pulled forward.

    if it was jamming in the cage it would be pulled backwards. the only way for it to be pulled forward is chain suck.

    Ah right, I see. I've confused myself now... :roll:

    When I was backpedaling the derailleur was being pulled towards the front of the bike. Just txt the mate who I was with to see if it was being pulled backwards or forwards when pedaling normally!??!
  • nicklousenicklouse Posts: 50,675 Lives Here
    Concorde wrote:
    nicklouse wrote:
    you say the mech is being pulled forward.

    if it was jamming in the cage it would be pulled backwards. the only way for it to be pulled forward is chain suck.

    Ah right, I see. I've confused myself now... :roll:

    When I was backpedaling the derailleur was being pulled towards the front of the bike. Just txt the mate who I was with to see if it was being pulled backwards or forwards when pedaling normally!??!
    then maybe a stiff link in the chain.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • concordeconcorde Posts: 1,008
    nicklouse wrote:
    Concorde wrote:
    nicklouse wrote:
    you say the mech is being pulled forward.

    if it was jamming in the cage it would be pulled backwards. the only way for it to be pulled forward is chain suck.

    Ah right, I see. I've confused myself now... :roll:

    When I was backpedaling the derailleur was being pulled towards the front of the bike. Just txt the mate who I was with to see if it was being pulled backwards or forwards when pedaling normally!??!
    then maybe a stiff link in the chain.

    Will take a look when I get back home. Looks like it could be any number of things! Great! :roll:
  • nicklousenicklouse Posts: 50,675 Lives Here
    I would not suspect the rear mech. i would not suspect the jockey wheels.

    front rings and chain.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • concordeconcorde Posts: 1,008
    nicklouse wrote:
    I would not suspect the rear mech. i would not suspect the jockey wheels.

    front rings and chain.

    Starting to think that myself. I will take a closer look tonight, I'll borrow a chain wear device thingy and check for any stiff links. Will also check the chain rings for wear.

    Cheers
  • concordeconcorde Posts: 1,008
    My mate says he's pretty sure it was pulling the mech backwards not forwards. Would make sense I suppose as if ti was pulling forwards this would not cause the chain to come off of the top rear cog. The derailleur pulling backwards is more likely to have this effect... (I think!)
  • nicklousenicklouse Posts: 50,675 Lives Here
    most likey a stiff link then.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • concordeconcorde Posts: 1,008
    nicklouse wrote:
    most likey a stiff link then.

    Appreciate the help Nicklouse. Will take a look when I get home from work.
  • MaroMaro Posts: 226
    I would have said maybe a stiff link, or perhaps the indexing is out and the low stop needs a tweak.
    Bird Aeris. DMR Trailstar. Spesh Rockhopper pub bike.
  • concordeconcorde Posts: 1,008
    Chain is fine. No stiff links. Think I've found the issue. Bottom jockey wheel has metal either side, it was all bent which is what chain was jamming in-between, that and the jockey wheel. After yesterdays snap some of the metal has actually snapped off. I think a mixture of the metal at the bottom being bent and the cage being slightly bent meant the chain was jamming. I'll order a new rear mech, just tried and the medium cage clutch SLX mech I want is now sold out! Not amused!!!

    Some pictures below, front chainrings look a bit worn to me too.
  • nicklousenicklouse Posts: 50,675 Lives Here
    replace the cage and it will be fine.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • concordeconcorde Posts: 1,008
    nicklouse wrote:
    replace the cage and it will be fine.
    Ah right, didn't know I could just replace the cage. Will get Googling.

    Cheers
  • concordeconcorde Posts: 1,008
    Doesn't look very easy to buy cages on their own. Part 10 I need off this diagram I think.
  • concordeconcorde Posts: 1,008
    This is getting beyond a joke now! Is there any other common issues that cause mech hangers to snap? I bought a new one for North Wales last weekend just in case one snapped on me, well it did!

    Rode CyB on Saturday, fine, towards the end gear changes were a bit rubbish, couldn't select biggest cog at the back. Thought nothing of it. Next day wrote Degla, three miles in, nearly at top of initial climb, snap! Mech through spokes, snapping cable! Replacement mech of no use as had no cable. Rode single speed. Was okay at the start then kept going on to bigger cog than I wanted, meaning chain was too tight and could barely turn the cranks!

    I've noticed that the rides it goes on is usually the ride after gear changes get a bit dodgy. I tell myself to check it before going out again, but I never do!

    But still, any other things I can check that may be causing this?

    I've been through 6/7 in the last 9 months!

    Cheers
  • The RookieThe Rookie Posts: 27,804
    I'd replace the chain and mech complete, one or the other is doing it!
    Current steed - Whyte T129, 2013 frame, mongrel Revelations, Giant dropper, Stans S1 wheelset. 12, Magura Trail Sport brakes, 1x11. 12.8Kg
  • nicklousenicklouse Posts: 50,675 Lives Here
    Concorde wrote:
    I've noticed that the rides it goes on is usually the ride after gear changes get a bit dodgy. I tell myself to check it before going out again, but I never do!
    so what is causing the gears to go dodgy?

    that will be your problem.

    if you dont check then things like hangers going will happen.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • The RookieThe Rookie Posts: 27,804
    I read it as the Hanger starting to flex, but with hindsight could be wrong.....
    Current steed - Whyte T129, 2013 frame, mongrel Revelations, Giant dropper, Stans S1 wheelset. 12, Magura Trail Sport brakes, 1x11. 12.8Kg
  • concordeconcorde Posts: 1,008
    I've replaced the mech and same thing has happened. I will be getting a medium cage mech shortly and I'll shorten the chain down for that at the same time. Or would I be better off getting a new chain at the same time?

    No idea what causes the dodgy gear changes, it's ok all ride then I couldn't select the top cog. On inspection before I rode the next day I noticed the top jockey wheel was touching the cog so I adjusted the barrel adjuster and this fixed the problem. (The jockey wheel was not touching the cog at the beginning of the ride on the start of the ride Saturday but by the end of it, it was?!)
  • cooldadcooldad Posts: 32,599
    The b screw sets the distance from the cassette, the barrel adjuster adjusts the cable tension. Nothing to do with each other.
    You need to read Parktools and adjust things properly.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • cooldadcooldad Posts: 32,599
    Adjusting the barrel adjuster, as in your previous post, without the low limit screw being set correctly will be what sends your mech into the spokes.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • concordeconcorde Posts: 1,008
    That's what I meant, I adjusted the B screw not the barrel adjuster. And the limit screws were set correctly before doing this.
  • The RookieThe Rookie Posts: 27,804
    The upper jockey location is a combination of factors, b-screw preload on the upper spring, and then the upper spring 'fighting' the lower spring, if something 'changes' it's still possible for the jockey to hit the lowest gear (biggest - top cog is the smallest, assume you meant biggest/first and not top?)
    Current steed - Whyte T129, 2013 frame, mongrel Revelations, Giant dropper, Stans S1 wheelset. 12, Magura Trail Sport brakes, 1x11. 12.8Kg
  • Chunkers1980Chunkers1980 Posts: 8,035
    That's for a normal style mech. Shadow mechs don't use a spring, it just pivots.
  • *AJ**AJ* Posts: 1,080
    First observation is that the bike doesn't look particularly well maintained in the pictures? theres A LOT of built up crud there! built up crud causes issues.
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